Take 1: Portable Generator and Manual Transfer Switch
After a few winters, we got tired of being in the dark and being cold with random windstorm induced power outages, so we bought a 5kW portable generator and used that for a storm or two. I even installed a proper 10 circuit manual transfer panel in the house and got the right hookups for the generator so it was a pretty seamless install. You still had to lug the generator out, hook it up, start it, transfer the circuits, feed it with gas, and put it all away when it was done - but it worked. Yes, it was noisy - but we fared a lot better than many of our neighbors did. Those 10 circuits gave us almost everything we wanted in the house - we could heat the place, have most of the lights on, watch TV, use the computer, and cook on a small electric skillet.
Here's a link to the Word document I created and printed out to label the breaker panel at this point. It includes the green labels you see on the transfer panel in the picture above, plus labels for all of the circuits in the main panel, a legend of what goes to what (I used a color printer to print it out), and clear indications of what circuits are on the manual transfer panel.
Take 2: Automatic Standby Generator and Transfer Panel
After a particularly long outage where we spent many hours hunting around for gas at local gas stations (no power == no working gas pumps. Oops!), we decided enough was enough and started planning for a much larger automatic standby generator that was permanently installed and ran off natural gas, with an option to run it on LP as well. The unit we selected is a Guardian 16kW air cooled generator - basically the biggest of the "light duty" units we could find at the time we did this install. After much hunting and pricing, we scored one delivered to our door for just under $3300. Everything was in the box - including a 16 circuit transfer panel and a composite mounting pad - making it a reasonably homeowner-friendly installation, even with the usual required permits and such.
NOTE: Now the air cooled generators in this category go up to 18kW, with more circuits, better controllers to keep the voltage regulation even tighter than it was on the unit we got, and all sorts of fun. And, it's not much more than the 16kW unit like we bought. The step up to liquid cooled is still a huge price jump (figure at least double the cost), unfortunately.
General Details about Automatic Transfer Switches and Panels
The transfer panel on the smaller automatic standby generators units wires pretty much like a sub-panel does - you install a large breaker in the main panel (70A in this case) and move all of the circuits to the sub-panel (aka, transfer switch). Anything in the sub-panel (transfer switch) will be energized when the generator is running and making power. This is easy to do and is only slightly more involved than the wiring for the manual transfer panel. They can be wired without turning off power to the entire house - you can move circuits over one at a time, and if you are skilled enough to add a new circuit to your existing panel, then you can likely handle adding a subpanel style transfer switch. You just have to know how to work inside the breaker panel - at least part of it is live all the time, so you have to not touch things you shouldn't be touching, and be aware of live conductors that can arc, spark, and do unpleasant things to you and/or your house.
The larger standby generators are sized to match the entire power feed to your house, or perhaps a sub-panel in homes with larger electrical services (say, >200A total service). In these "whole house" style generators, they simply place the automatic transfer switch between the power meter and the main electrical panel. When it switches over, it switches the entire load of the house over. The larger units are most definitely not a homeowner friendly project - they require working on the main power feed for your entire house, very large wires, and will definitely require you to talk to the power company ahead of time to arrange the work since they have to pull the meter to your house and then come and hook it back up afterwards.
Research and Planning
I researched the unit pretty extensively and made sure we could fine-tune the panel for our needs before buying it. We knew we were going to convert as much of the house as possible to gas (see the appliances page for more details) and thus would be substantially reducing the "must have" electrical load on the generator. That allowed us to move more "nice to have" 110V circuits over. The transfer panel came with three 220V breakers wired in, and I'm planning to only use two of them. The other circuits will be used for 110V breakers (2 extra over the as-delivered configuration) for a total of either 12 110V circuits breaker slots and 2 220V circuit breaker slots. The transfer panel takes standard Siemens breaker (Type Q) that are readily available as replacements in various styles and amperages. You can even get "double breakers" in this style - the kind where you get two breakers in a 1" single breaker slot. I have a lot of 15A circuits in my house - 6 out of the 10 total circuits on the manual transfer panel, with the other 4 being devoted to 20A circuits. On the new transfer panel, I have one 50A 220V circuit available, and I'm going to use it for our oven. There is a 20A 220V circuit that will power the air conditioning nicely. The existing 10 circuits from the manual transfer panel will move over as-is (though I will have to buy appropriate sized and typed - aka GFCI or AFCI - breakers for them), leaving me with 2 extra circuits I can move. I know I want to move my pond pumps and exterior lighting over to keep the fish alive and light the exterior for safety (1 20A 110V circuit), and I can move the bathroom outlets over as well (1 15A 110V GFCI circuit). That uses up all of the existing breaker slots in the transfer panel. Since I can move to double breakers in a few slots, I'd also like to move over the dishwasher (1 20A 110V circuit), and the front and side spotlights (1 15A 110V circuit), and leave an additional slot (15A 110V) for a later hard-wired smoke detector circuit.
Many of these circuits will see only intermittent use (like the oven), so managing power on the generator will be doable. My main concern is overloading the 70A breaker or wiring that controls the sub-panel during "normal" use via utility power. That wiring - and the sub panel itself - has a limit and it cannot be overloaded. The other consideration is what happens when the generator kicks in and stuff is going full-bore in the house (aka, cooking a turkey or something else in the oven) when it will see full load applied to it without warning. That could also be a problem. Maybe I'll have to choose between my AC and my dishwasher. Life is full of hard choices... :-)
Here's the transfer panel as it came in the box.
Here's the transfer panel with the circuit breakers swapped out and rearranged for the first test fit of things. I also have a Word doc showing this iteration of the circuit breaker layout and usage.
After I did this, I realized the original wiring from the transfer panel had each wire nicely labeled at the main panel end with the breaker location in the transfer panel, so in doing the re-work above I made the labels wrong and thus made things very confusing down the road. So, I went back to the drawing board and came up with a different breaker layout for the transfer panel. This one preserves all of the original wire locations (they needed to be matched to the breaker capacity/amperage in each slot) and that still worked for what I needed. I also added a new circuit for a later addition of hard-wired smoke detectors throughout the house - I definitely want that to be on the generator. This one also changes out a few of the breakers for ground fault (GFCI) units and a couple more for arc fault (AFCI) units. The regular breakers are pretty cheap (<$10 each) but the GFCI and AFCI units are over $30 each. Ouch.
To do this work, I needed to buy a few new breakers - they are all Siemens type Q breakers.
I was also left with a number of extra breakers from the transfer panel, all Siemens type Q breakers.
More research revealed that the subpanel inside the transfer panel had a maximum rated capacity of 100A, so I switched to a 100A breaker in the main panel and upgraded the wiring inside the transfer panel and between the main panel and the transfer panel to handle the new max 100A load. After getting everything in place and dealing with a few Edison circuits, I had to juggle a few more things to come up with a final circuit breaker layout for the transfer panel. This one even allowed a few more circuits to be moved over - after testing the loads, I found that I could pull a max of just over 60A through the transfer panel, even with the oven broiler on high.
The major electrical power users in your house will be appliances - microwaves, ovens, AC units, etc. - next to them, the lights, TV< and computer gear will use very little power in comparison. And many appliances - like an oven or an AC unit - will run for long periods of time, often when you are not home. Many people stick a roast in the oven and head off to church so it's ready when they get home, for example. This creates concerns for a automatic standby generator - it will attempt to power the entire load on it's subpanel when the transfer switch kicks in. If multiple high-drain appliances are ready to suck power as soon as it comes on, then that could be a problem. If the generator kicks on and then overloads itself and trips the breaker at the generator (there's one there to prevent overloading the generator itself), then you have no power until someone manually resets things. That sort of defeats the purpose of having an automatic standby generator in the first place, so you definitely do not want to do something like that.
As I thought through this problem, I realized that that many appliances - both the hard-wired and plug-in kind - will reset themselves to a "standby" or "off" state upon power loss. This is particularly true of electronically controlled appliances, and it's a very good thing for what we care about here. For example, if your microwave is busy microwaving something and the power drops out, when the power comes back on, it will not be microwaving anything - it will be sitting there doing nothing other than flashing the clock to remind you to re-set it. A dishwasher may or may not follow that, and the same goes for a clothes washer and stove. On the other hand, you have appliances like the AC compressor which will be on if the thermostat is calling for it, and thus may be loading the generator as soon as the generator comes online during a power outage. You need to experiment with your particular appliances and see what does and does not work for you. You can do this by manually cycling the circuit breaker off while the appliance is doing it's thing, waiting 20 seconds, then cycling the breaker back on again. If the appliance comes back on at full-bore, that's what will happen when the generator comes on. If it stays "off", then that's better for what we care about here.
The idea is that the subpanel in the automatic transfer switch can handle a somewhat greater total load than the generator can supply. Generators are typically sized somewhat less than the normal max utility power you can draw. That's fine during normal utility power being applied so long as your wiring and the breaker that feeds the subpanel in the automatic transfer switch is sized to match your intended load. The problem is that you need to manage the load on the generator so you do not overload it. This is generally easy - simply don't turn on everything at once while you're running on generator power, especially high drain things like the stove, microwave, and AC. Those are easy enough to manage once you know you are on generator power - but what about the first few minutes when the generator kicks in during an outage. Even if you are home (which you may not be), you want to be assured that you will not immediately overload the generator and have it trip it's internal breaker. Running out to the backyard or garage and flipping breakers on/off completely defeats the purpose of the automatic transfer switch and auto-start of the generator. Thus the interest in what high-draw appliances will and will not come back on in a running state when the generator power comes on.
Generator Install Planning
Here's the pictures I took as I was scouting out an install location. They were also used to determine the new gas meter location - see the section below on upgrading the gas line and meter for details on that. I was originally hoping to put the generator on the side of the house close to the electrical box, but the setback rules from the property line nixed that idea. When the problem of needing a bigger gas line and meter came up, I decided to put the new gas meter on this end of the house - it's much closer to the gas appliances that way and I save myself from having to run a huge gas line all the way from the other end of the house to where the generator is - it cuts the length of the gas line run by about 2/3rds and keeps it entirely outside of the house - just dig a trench and go.
You'll have to research code in your area to get the exact data, but the general rules are that the generator has to be 3' from combustibles where the exhaust comes out, 10' from an openable window/door, needs 3' of service access in the front, and 18" (I've rounded up to 2') of clearance/access on the "cool" end of the generator. There will also be rules for the required setback from the property line - in my area the setback requirement looks to be 5'. Keep in mind that you cannot plant bushes or shrubs too close to the generator - they are considered combustible.
Due to the placement of my house relative to the property line, I wasn't able to put the generator right next to the house near where the transfer panel is. Instead, I've opted to place it away from the house in the back corner of the yard, so the 5' property line setback requirement also meets the 3' combustibles setback requirement. I just need to keep 3' in front of the unit clear, as well as 2' to the side away from the property line. The actual code is more like 18", but I rounded up to keep the measurements simpler. It's going to be lawn there, so no big deal exactly where the edge of the lawn is so long as it's a few inches away from the generator base. For my landscaping, some rocks or gravel around the generator will fit right in and help keep things low maintenance, free of problems, and easy to clean up. You need to periodically remove any stray branches, leaves, and other yard debris that blows into that area. Also, in my yard that area is basically unused space, so putting the generator there is fine by me.
The diagram below shows the rough layout of the location where I plan to install the generator. The fence is on the top and left, and the fence is on the property line in both cases, so I just measure off the fence and I'm done.
These pictures show the actual generator install site with the approximate location and setbacks painted on the ground. Note that the site is not level - I will have to address that when I prepare the site. Note the pile of retaining wall blocks in the pictures. I had bought them for another project that never happened, so they're just sitting around unused. Given that I need to level that area, they may come in very handy for this project. :-)
You have to get gas and electrical lines to the generator, and the trenches for those need to be dug before you install the generator and before you even lay down the gravel that goes under the generator pad. Remember that you need two trenches - one for electric and one for gas - and they must be a certain depth and a certain distance apart. In my area, they need to be at least 24" apart and 24" deep. Your local home center should be able to rent you a walk-behind trenching unit that can dig the required trenches with ease. You just need to be sure that all of the local utilities are clearly marked before you start digging. Nailing a water line is a messy experience - see further along for details about my experience with that. Hitting a gas line or a buried electrical cable could be deadly. Getting someone out to fix it is expensive - especially since it's "emergency service" and you pay extra for that. Check before you dig - most local utility companies will gladly help you get a locating service out to your house to check on things.
In my case, the new gas meter (see below) ended up being about 60' away from the generator in a straight line. The only buried things I need to worry about are the water line which is right up near the gas meter, and a "French drain" for the downspouts that runs along the side yard. You can see this drain pipe in the meter install section below - it runs parallel to the house, about 3' away from the foundation. I just need to be sure the trenching process doesn't cut into this pipe or unduly disturb it.
For moving the generator, I saw a neat trick on Ask This Old House. They installed one of these generators in a recent episode, and to move it, they slid two 8' sections of metal electrical conduit through the unit - there are holes just for this purpose near the bottom of the generator - and used those sections of pipe as lifting points. By doing that, four guys could pick it up and move it around reasonably easily. It weighs about 450-500lbs, so with 4 guys they are each lifting around 110-125lbs. That's heavy, but doable. Find a few some strong friends who work for beer - just be sure to pay them their beer after they help you put the generator where you need it! :-)
Upgraded Gas Line Install
A generator uses a lot of fuel at full load - it dwarfs the consumption of pretty much any other gas appliance in a typical home. A chart of some typical gas usage rates is below - as you can see, the generator is the biggest by a good margin. This means that the gas line into your house and your gas meter may not be large enough for your desired usage. You may also need to upgrade the gas line inside your house, depending on what other appliances you want to convert to gas. In my case, I was going all out to convert to gas, and I wanted a tankless hot water heater (which is a pretty large gas user at full load) - and the original gas service to my house was barely adequate for my existing usage, so I was going to have to upgrade all of it.
One really cool thing was how they joined the flexible plastic pipe sections and fittings - they are basically "welded" together using a special holding fixture. The fixture holds the tubing in alignment and allows you to bring the ends together or pull them apart with a lever. There is a cutter you insert to square off the ends and the tubes, then you insert a two-sided electrically heated metal plate that acts like a large soldering iron. There's a temp gauge on the plates that you watch, and when the ends of the tubing get hot enough, you remove the heated plate and use the lever on the holding fixture to bring the ends of the tubing together. They melt together and as they cool, form an incredibly strong joint with just a barely noticeable ridge. The guys doing the work said the joint is so strong that the pipe will break before the joint will. It was very fast to do (just a few minutes per joint) and was a very clean install when they were done. This gas line should work virtually forever without any problems due to leaking joints and without any corrosion-related issues.
In addition to the manual shutoff valve, they also installed an automatic one. Should the line "blow out" anywhere, the automatic valve senses the "too high of a flow rate" and shuts off the line right next to the main connection. It will auto-reset after the line is fixed. And it's a completely mechanical valve that is buried and pretty much never needs service. Nifty! I feel much safer knowing that's on the gas line.
Here's some photos of the PSE folks putting in the new gas line. Notice that it's yellow flexible plastic tubing of a larger size, and that they used an air powered boring machine to tunnel the hose from one place to the next - this allowed them to keep the digging and disruption of my yard and the street to a minimum. With the gravel back down, it's hard to tell where they were digging at. My wife looked at it later in the evening and said "Where'd they dig? I can't tell." - and that's a very good thing. The crew was great - very nice guys that did quality work and answered any questions I had about the work. The final install looks good and will work great.
Here's the final install of the meter and the cover for the shutoff valve near the street. Check out some of the rocks they dug up - I asked to keep them so I can use them for some of the landscaping out back later on. Big rocks make nice feature pieces in a rocky area, and they're free for the taking if I grab them now.
Here's some photos of the new gas line work that feeds the stove, dryer, heater, and tankless water heater. In the first picture you can clearly see the T fitting where the generator will hook up - it's pointing down from the main feed. There is also a capped T fitting in the crawlspace for a possible later BBQ and gas fireplace hookup. I did forget to have a T fitting installed above the garage ceiling for a later heater in the garage, but that's relatively easy to add when I want to do that.
Help from Ask This Old House
As if by luck, shortly after buying our generator but before I installed it, Ask This Old House ran a segment that included installing this exact generator and transfer panel - and that episode is saved safely away on my Media Center for later review during the installation work. I took pictures of the TV with the install paused at some relevant points.
The first picture shows the final electrical and gas line hookups on the back of the generator - important points are 1) that they wired the electrical directly to the generator without the connection box that comes with the install kit, and 2) the gas line arrangement with the flex line running straight so it can properly absorb any vibrations from the generator while it's running. I've also seen the line run parallel to the back of the generator - as long as the line is not bent (aka, it runs straight), it should work fine. The second two pictures show the box where the electrical lines from the generator connect to the lines form the transfer panel. This is not the box included in the kit, and it appears to be a breaker or disconnect panel rated for outdoor use. Conduit from the generator runs underground and then into the bottom of this box, and the flex conduit from the transfer panel runs into the back via a hole in the exterior wall of the house.
Not shown here but contained in the show is an easy method for four people to lift the generator using 2 long sections of pipe placed in holes in the base of the generator that are designed for this purpose. That will be much easier than lifting and carrying the unit by trying to grip under the base.
Gas Pipe and Electrical Conduit to the Generator
This is the biggest part of the job when remote-mounting a generator - you need to get fuel out to it, and power back from it. It consumes a lot of fuel, so the lines need to be large, and it puts out a fair amount of power, so the electrical cables need to be large as well. Burying gas pipe and electrical conduit carries a variety of problems that need solving, and they need to be done right. This stuff can kill you if you do it wrong, either by explosion or via electric shock, or both. For me, that meant getting a professional into to run the gas line after I dug the trench.
Digging the trench turned out to be an ordeal undo itself - thank God I wasn't paying someone by the hour to do this. First we ran into huge roots near the generator site coming from the cedar tree in the neighbor's yard. Then the soil was so sandy and filled with small 1" - 2" stones than trench was collapsing in on itself as soon as the trencher got done with it. Then the small stones were getting into the trencher gear and clogging it, requiring lots of "manual intervention" to keep it working. Then we found the remnants of a HUGE cedar stump up near the house while digging the electrical conduit - it was nearly four feet across at the spot we needed to go through for the electrical lines. Then we accidentally ripped up the "French drain" system for the downspouts on the house. The the trencher nearly fell into the trenches as we were trying to finish up - and in the process caved in the final 6' of both trenches. So much for getting a deal on an extra hour of a trencher rental from a buddy.
After that, I tried to dig out the trenches by hand - but between root, rocks, unstable soil, and a five year old daughter who thought collapsing the trenches was a fun thing to do when bored - that effort didn't go so well. So I decided to rent a small excavator (3500lbs unit weight, approx 36" wide with tracks that expanded to approx 54" wide) and just dig the whole area up and go from there. I figured that I had to dig it up to fix the drain system anyway, so I might well quit playing around and just get it dug up. Plus I could split the rental with another buddy who was also installing one of these generators and needed to dig a trench to his generator site the same as I did.
Things worked very well at first - until I hit that stupid stump. Cedar is very rot resistant, and this stump was huge, so even though it had been dead in the ground for years, it was still quite strong. I fought with it using the excavator, hand shovels, and a variety of axes. My big axe even sacrificed it's life (busted handle) on this one. Finally, I got most of the way through it, but it was a chore. I still had to remove a large section by hand later on when I ran the conduit for the electrical stuff. I even got the drain pipes dug up without too much hassle. So far, so good, right?
Then, at the very end of the trench, disaster struck. The main water line turned out to be a scant 12" below grade right where I needed to dig, and faster than you can say "waterspout", I had water shooting 30' down the ditch. After some panic getting the water turned off, I was able to finish the excavation and move on to my buddies house to dig his ditch. Oddly enough, that dig went off about as textbook perfect of an event as could be hoped for. We only had one large root that needed to be cut out of the way and nothing else surprising happened. Back at my house, things were different - emergency plumbing service is expensive, and I paid through the nose (and a few other orifices) for it. The pull from the excavator managed to trash a 4' section of water line outside the house, and it pulled on the line inside the house hard enough to break it up inside the back wall of the garage by the main shutoff valve inside the house. All thanks to the @#$%^ idiot who installed that water line when the house was built. The line under the foundation was barely code depth and the line from the meter was at or below code depth (24" deep), but in the infinite wisdom of the person installing that final 4' of pipe into the house, they decided to install the line near the house - right where digging was most likely - with a huge "hump" in it that brought the copper line up to about 10" - 12" below grade. Maybe you couldn't be bothered to actually cut the copper to length so it would bury correctly? Or you were two lazy to dig the final 4' section of the ditch to the correct depth? You sir, are a moron, and if I ever find you, I'm strongly considering taking the $1700 of plumbing costs that your sub-standard work cost me straight out of your hide. (There, I feel better now. Sort of. Actually, not really. That $1700 was going to be a new big screen TV for my living room. Ugh.) You can see the new water line with shutoff valve in some of the pictures. That makes for three shutoff valves in the line - one at the meter, one buried next to the house, and one in the back garage wall. It's Yet Another Buried Thing that needs an access method in my side yard. Yay.
The gas line install eventually went OK, but not before some confusion on the part of the installer. Due to the distance to the generator and fuel demands of the generator, I had spec'ed out a 1 1/4" line to be installed from the meter to the generator. They showed up with a 1" line with 3/4" connections at each end and no 1 1/4" fittings to connect to the gas line on the side of the house. Yep, my luck was acting up again. A quick trip to their supply house remedied the missing parts and I eventually got 1 1/4" hose with 1" fittings at each end. However, they did - for reasons unknown to me - install a section of 1" line on the side of the house between the 1 1/4" fitting on the main gas line and the 1 1/4" riser going into the ground. The short length of 1" pipe on the house should work out OK - hopefully there won't be enough pressure/flow drop in that short section of line to matter. I'm also not happy about the multiple unions they used to do that short stretch of 1" pipe on the side of the house, but it ought to work. The actual gas install worked fine and passed code without a hitch. It managed to hold 25psi of air for days without any problems, and the code is to hold 15psi of air for 10-15 minutes. At least I'm safe from gas leaks, I hope...
The electrical conduit is 1 1/2" and will hold one 8 gauge wire for the ground (green), three 4 gauge wires for the power + neutral (red, black, and white), and four 18 gauge wires - two for the 240V AC signal wires to the generator (blue and yellow) and two for the 12V DC wires (orange and brown) to control the transfer switch relay. The original power + neutral wires were 6 gauge, but due to the distance involved being borderline for that size cable, I moved up to the next size to be sure it was big enough. The increase in the size of the cable means I need to increase the conduit from the 3/4" conduit that comes out of the generator to at least a 1" conduit. I was going to use 1" conduit and had even bought some, but after thinking about pulling all those wires through a 1" conduit, I decided to upsize the conduit run to 1 1/2" - you can't really use too big of a conduit and the bigger it is, the easier it is to pull the wires through it.
The kit that comes with the generator assumes it will be set near a house and that you can mount the junction box right on the house. If you look at the photos from the install done by Ask This Old House, it shows the underground cable going straight up and into the generator. Rather than add a post next to the generator for that junction box, I can get rid of it entirely by doing things the way Ask This Old House did. In the end this will result in a much cleaner install with fewer external junction boxes. I had bought a section of 1" liquid tight flexible non metallic tubing to make the final hookup from the PVC underground conduit up into the generator. To use it, I would have needed to step the size down right where the conduit come out of the ground (1 1/2" to 1"). However, changing conduit size in the middle of a run is a no-no, so I would have had to use a proper pull point so I can access the wires at the size change in the pipe. Even with the 1" conduit I would need to suitably enlarge the hole in the back of the generator to accept a 1" fitting and get the cable hookups done correctly inside the generator, so I eventually opted to use larger 1 1/2" flexible conduit to make the hookups - see the Final Hookups at the Generator section below for details on that.
Fixing the French drain system for the downspouts was a pretty straightforward matter of buying some pipe sections and sticking them together. Since the entire point of this thing is to let the water drain into the ground, you don't even need to glue the sections together if you don't want to. I opted not to. The final sections at the end have holes drilled in the pipe to let the water out. You cover the pipes with rocks and some filter fabric to keep the dirt out, and then cover it all with dirt. Very simple, but you have to get the "clean" rocks from somewhere... Borrow a pickup and head to the local rock/quarry type of place and load up.
The conduit went into the trench easily enough - glue the sections together and glue the bends onto the ends along with some short upright sections to get things above grade. I placed temporary caps on the exposed ends of the conduit to keep water out - you can grab these from the plumbing supply section of the home improvement store. Schedule 40 PVC electrical conduit is the same dimension as schedule 40 PVC water pipes. Normally you shouldn't use PVC water fittings for electrical use, but since it's just temporary to keep the water out it'll be fine. I'll remove them before I complete the install. (Why not use PVC water fittings or pipes for electrical use? The electrical fittings are specifically made to not have any sharp edges on the inside that could damage a wire while pulling it through the conduit. You have no such assurances with water pipe/fittings and inadvertently stripping the insulation off of a section of wire in the middle of a run of conduit could be a very bad thing... Just Say No to using PVC water fittings and pipe for electrical use.) The section of conduit to get up near the house was a bit tricky. Because the gas line was in the same area, I ended up using two 90 degree bends to make it work. One bend turns towards the house, the other turns upwards to get the pipe up and out of the ground. I only have three 90 degree bends in the conduit, so I'm fine for pulling - I believe code is a pull point every 360 degrees of bends. I was trying to avoid the extra 90 degree bend by using the flexibility of the conduit to make an gentle/easy "sweep" to turn towards the house, but it didn't work out. I ended up cutting off the already glued on upright bend and adding another one plus a coupling to make it all work. I guess I should have test fit things in place before gluing them up originally, but I didn't. Live and learn. At the generator end, it's a simple matter of cutting the conduit to length and completing the gluing operations. I had to re-excavate a few feet of trench at the generator end thanks to my trench-collapsing 5 year old daughter, but it wasn't too bad. Once a section of conduit was in and the drain was done in that area, I started backfilling the trench and tamping down the dirt. Walking back and forth on the dirt helped tamp it down, and having a semi-level surface of dirt (once the pipes were buried) made walking around in the trench much easier. It also made getting in and out of the trench easier since it wasn't quite so deep anymore. One all of the conduit was in and glued together, the rest of the trench was backfilled and tamped down. There was a lot of dirt to move to finish filling in the trench, but it went fairly quickly with some help from a friend.
The last piece was to prepare the level gravel pad for the generator to sit on. I put landscape fabric down to help prevent weeds, and a small retaining wall to make it easier to create a level pad. Another load of gravel and some quality time with the tamper got the job done.
P.S. - In some of the first pictures you can see the enormous pile of scrap wood I had to move to dig the trenches. That wood was leftover from various other project and has been sitting there for a year or more. When I moved it, the entire pile turned out to be completely termite laden, so I promptly burned it. You can see traces of the fire in the later pictures. It went up in smoke quite nicely. Bye, bye termites...
Transfer Panel And Wiring Snake
The transfer panel needed to be mounted next to the existing break panel and the wiring snake that came pre-attached to the transfer panel needed to be run back through the garage to meet up with the underground conduit running out to the generator. The mounting for the transfer panel was pretty simple. The exterior wall on my house is just 5/8" plywood with vertical grooves on the outside, and I didn't feel it was thick enough to mount the transfer panel using the existing/factory mount points, and I didn't want it to sit any further outside of the stud bay that it already would - it's pretty deep compared to a normal breaker panel. To mount it securely to the studs but still be inside the stud cavity, I simply spaced out one side of the stud bay to make the opening the same width as the transfer panel and then drilled holes in the sides to mount the transfer panel to the stud/spacer using lag bolts into pre-drilled holes. If you have a standard 16" on center stud arrangement, you'll need a 2x4 and a section of 5/8" plywood cut to the same width as a 2x4 to make the spacer. I also mounted two support blocks below the transfer panel, leaving them about 1/8" away from the exterior plywood to allow the factory mounting plate to slide behind them. The support blocks hold the weight of the transfer panel while you are installing the first lag bolt, and they help hold it up after the lag bolts are installed. It's simple, and very solid.
The wiring snake provided by the factory is only about 25' long - way too short for my final install. But it was long enough to get the wiring to the rear of the garage where I could use the factory provided hookup box to make the connection from the factory wiring snake to the wires that will run to the generator via the underground conduit. This saves a bit of money - no need to buy a separate connection box - and cleans things up at the generator itself by connecting the wiring directly into the generator itself - no extra post and connection box are needed there. I routed the wiring snake through the open rafters along with the other house wiring, and into the attic at the rear of the garage. Rather than try to drill through a rather large piece of the house structure where the open rafters meet the attic (it's basically a triple thick rafter with metal ties in/on it), I opted to run the snake below that one triple thick rafter and up through the drywall into the attic. This hole in the drywall will have to be patched to keep the fire-break between the garage and the house, but compared to drilling a 1 3/4" hole (yes, you need one that big to get the snake through it, especially if it has the end still on it) through a triple thick rafter and likely dealing with hitting one or more metal tie plates, and having to drill from a very awkward position on top of a shelving unit, it's a reasonable trade-off. The metal snake is going to protect the wires inside quite nicely for this short piece that runs below the rafter assembly.
The hookups at the connection box went pretty smoothly. Since I ran 1 1/2" conduit underground, I needed to enlarge the center hole in the bottom of the factory provided box to allow the 1 1/2" conduit to connect. It was very tight, but after a lot of quality time with the Dremel and one dead grinding wheel - it worked. I plugged the factory hole at the bottom left with a steel plug, and I had to move the ground connection to the right lower side wall. The factory snake enters the rear lower left of the box through a provided knock-out. The hole in the wall needed to be 1 3/4" to allow the snake end piece to fit properly, and I had to push the connection box and the conduit off to the right a bit to allow that huge hole in the wall to clear a gas pipe running to the dryer, but it all worked without much trauma. I even remembered to caulk around the opening in the wall before I mounted the connection box to the wall, and I also remembered to give the connection box a quick shot of grey paint where I had to grind away at things. No sense putting it in and having it rust out in a few years, right? I even remembered to apply expanding foam from the inside to make sure it was really sealed up tight.
The connection of the transfer panel to the main break panel was a lot of work. I had to run larger 3 gauge cables to carry the full 100A load the sub panel was capable of, and the swap out a bunch of the breakers for AFCI, GFCI, and "double breaker" (two in one, or half-height breakers) to make it all fit. That meant pulling some new wires though the original conduit for the extra circuits, and that pretty well maxed out the original conduit (it was close to the max fill rate, even after I removed the original power cables) and I still needed a couple more wires. I have a lot of very lightly loaded circuits in my house - even with all this I was not able o get my total draw on the transfer panel - including the oven - past 60A per leg. Anyways, I'll be adding another 1 inch liquid-tight non-metallic conduit run on the bottom to handle a few extra wires for the extra circuits. I also moved the wiring for the stove to go directly into the transfer panel - it had the extra cable already in the ceiling and I really don't like using splices on large gauge cables. The shots with the cables hanging out of the box were during the planning and verification phase of this. Things were buttoned up properly after these were taken - see below. I'm just showing the real effect that moving this many circuits has - you end up dealing with a lot of wires and paying attention to details plus doing things in a neat and workmanship-like fashion really pays off in the end! You'll notice that the transfer panel wiring is done nice and neat with no messy wiring. Getting the wiring in the main panel so nice is a bit of a chore, but worth it in the end. Also, I took the time to mark the new wires I pulled with colored electrical tape on each end to make identification easier. I was not able to get individual 6' runs in various color and stripe combinations easily, so I used all red for the extra hots and and all white for the extra neutrals, and tagged them accordingly. Since I have a number of AFCI and GFCI breakers, marking the neutrals proved very helpful for them. Also, I rapidly learned the now-obvious detail that you can't add a GFCI or AFCI breaker to an "Edison" circuit. Live and learn... :-)
Even though I have a few Edison circuits, I pulled a neutral for every hot just in case I needed them in the future - it's much easier to pull them now than later. That means that I have neutrals capped off in the main panel, but they are there if I need them. I also have one extra circuit pulled so I can add hard-wired smoke detectors to the house later on.
After cleaning up the rats nest of wires and doing some final circuit juggling to get everything moved over and working properly, here's the result. Everything is clearly labeled on the panels and nothing is hanging out in the open. The color-coded printed labels you see on both panels are in Word documents I've linked to below, in case you want to see them in detail or you find the labeling here useful for the panel(s) in your house.
Here's the final circuit breaker layout for the transfer panel. This one even allowed a few more circuits to be moved over than I originally planned for - after testing the loads, I found that I could pull a max of just over 60A through the transfer panel, even with the oven broiler on high.
Here's the final circuit breaker layout for the main panel. You'll notice that there is very little left on the main panel. Just a few spare circuits, stuff in the shed, the air compressor in the garage, the electric dryer, and the electric stove outlet I have in the garage (I use an old electric oven for powder coating). Eventually I plan to add a separate 70A sub panel on the back of the house for a spa/hot tub, and I've left a double breaker slot in the top section allocated and marked for that.
Getting the generator in place was a simple, if heavy matter. With the help of three friends, we used some 3/4" galvanized iron pipe sections to lift the unit and carry it into place. There are holes in the lower part of the generator designed specifically for this purpose, very thoughtful of the manufacturer. Other than setting it down, there wasn't much else to do. The old adage of preparation being most of the job really is true...
Wiring to the Generator
The end of the snake and the wires from the generator had a special "weather tight" connector on it for the four 18 gauge wires - if you are using the kit as-was, then it's a simple plug together matter much like a automobile wiring harness. Since I was adding a 70' section of wires between the snake and the generator, I was going to have to deal with that connector. Luckily for me, that exact connector is sold by one of the companies I deal with for automotive electrical connectors. It's a Deutsch DT04-4P connector and I can get all the parts I need from Terminal Supply Co. to make up a mate for it quite easily. Terminal Supply Co. also carries the crimp-on ring terminals I'll need to connect the power + neutral and ground wires to the various studs they need to go to. I just needed to go measure all of the mounting studs to get the right size opening, and then match that up with the wire sizes that will go to them, and order the required parts to get the job done.
Below is what I had to buy to make the connections inside the factory connection box where the new wiring from the underground conduit hooked up to the factory snake. Be aware that the three large connectors for the two hot wires plus the neutral required a very large crimper to get the job done. I happened to have an automotive battery cable crimper available and I used that. I was able to use a normal hand crimper on the ground connection, but just barely.
The most troublesome piece is the special Deutsch connector used for the 4 signal wires. I removed the wires from the original one at the generator by first removing the small green "secondary terminal lock" from the middle of the connector on the pin side. It pried out with a small jewelers screwdriver. I was then able to hold open the tabs that held each of the four pin terminals in the connector body, and then remove the red seal from the rear of the connector with all four wires (with pin terminals still attached) running through it. Then I could easily remove each wire + pin terminal from the seal. Since I was careful about how I removed everything, I could reuse the connector body, seal, and secondary terminal lock - all I needed was four new pin terminals.
Pulling the wires through the approx 70' of underground conduit out to the to the generator was most of the work. There were 3 #4 AWG wires (two hot + one neutral), a #8 AWG (ground), and 4 #18 AWG wires (signal wires between the generator and transfer panel). Lots of pulling lubricant and a couple of good helpers made it pretty easy. We put four spools of wire on the ground rod and hung in between the rungs of a ladder to let the signal wires pull off easily. The ground and three large wires were simply stretched out across the yard and routed into the conduit. I guided the wires into the conduit and made sure to apply plenty of cable lubricant, one helper did the actual pull, and another helper made sure the large wires didn't have any kinks in them plus helped apply the cable lubricant. Once you get that on your hands (or disposable gloves, like I used) it will get on anything you touch. This means that the person guiding the cable into the conduit end and applying the lubricant won't be doing much else.
I found a really simply trick to make pulling wire through new conduit easy. First, tie the end of some mason's twine to the handles of a very thin plastic bag, like the kind you get at a grocery store. Insert the end of the bad into one end of the conduit. Hook up a shop vac to the other end of the conduit and do what ever you need to so that you get a good seal at that end. When you turn on the vacuum, the bag seals the other end of the conduit and will get pulled down the conduit at at amazingly fast rate if all goes well. You'll hear it go into the vacuum so you know when to turn it off. Cut the plastic bag off the twine, and tie the twine to the end of your desired pull rope and pull the rope back through the conduit to the original end. Then you're all set to pull. I bought a small tool to hook up to the wires. It looks like a Chinese finger puzzle and it works amazingly well. I taped all of the signal wires together so one wouldn't fall out halfway through the pull, then taped that to the other four large wires, and then put the pulling took over the end and tied the pull rope to the tool. Simple, fast, and it really does work. You may need to use a smaller piece of plastic (aka, cut up the bag) for smaller size conduit, but the basic idea is the same.
The wiring posts in the connection box are #10 studs, fine thread (32 TPI, if my memory is right) and I had originally picked up an extra set of nuts, lock washers, and washers to use here. I bolted down the wires from the snake, and planned to use the washers and extra nuts + lock washers to connect the wires from the generator. The first set of nuts + the washers on top will give me a bit of a spacer to allow the second set of ring terminals (from the wiring to the generator) to mount to the studs without excessive bending, cleverness, or swearing being needed. The studs are plenty long enough to do this, so I figured I should make this as easy as possible, especially since the total cost of the extra nuts and washers was less than $3, but after I saw the first one hooked up, I decided against doing this. I mounted everything under one nut so that it would be all the way down the stud and that the terminals would be "beside" the plastic arc protection pieces that come in the box. With the second set of terminals spaced out on top of the first set of nuts, I was a bit uncomfortable with the distance from the side of the terminal to the main mounting bolts for the box - it looks like a serious arc hazard to me, so I opted to do a bit more work to get the wiring installed "correctly".
Sadly, I neglected to get any pictures of the actual wire pulling.
Final Hookups at the Generator
The actual hookups at the generator went surprisingly well. The wiring was easy, though I did have to fit the conduit into the hole to get the final wire lengths, then pull it out, cut the wires, install the ring terminals for the neutral and ground, and then do the final conduit install. The only real way to get the wiring into the breaker terminals was by doing it as you installed the conduit, so that's what I did. The wiring was just too short and too stiff to really do anything else. The neutral and ground hookups were pretty simple - run the bolt through all of the ring terminals, and bolt it down. The signal wires were easy to crimp terminals onto and install onto the terminal block after the rest of the wiring was done - it's just small gauge wiring that's easy to maneuver around the other wires and an automotive style crimper worked fine to install the terminals.
Below is what I had to buy to make the connections inside the generator where the new wiring from the underground conduit hooked up to the generator internals. Note that the two main power leads (#4 AWG wire) connect directly to the circuit breaker assembly in the generator and require no extra connectors to be purchased. Be aware that the large neutral connector required a very large crimper to get the job done. I happened to have an automotive battery cable crimper and I used that. I was able to use a normal crimper on the ground connection, but just barely.
The gas line took a bit of fussing to get everything perfect and make sure the flex line was installed without any bends in it. We also made sure to include a proper union and shutoff valve for later service. I even remembered to paint the gas pipe grey to help prevent rust. I also fogged the back of the generator near the electrical conduit - while making the larger hole for the fitting, I managed to scrape up the paint and didn't want it to rust out.
The flex line and generator hookup used 1/2" NPT fittings, so that's that the final sections of pipe, union, and shutoff valve are sized at. It makes for a dramatic step down to go from the 1 1/4" pipe to the 1/2" pipe in a single fitting, but it's what is needed here. The short run of 1/2" pipe will flow the required amount of gas for the short distance right at the generator, but not for the long run back to the house. I probably could have gotten by with a 1" line back to the house, but it was right on the border, and I decided to go larger to be on the safe side.
The flexible electrical conduit is 1 1/2" liquid tight flexible metallic conduit - not the non-metallic kind. We had a hard time locating the right non-metallic fittings and conduit, and this worked out for us. I got the 90 degree fitting on eBay from a surplus store for a good price. It pays to look around when dealing with stuff outside what you can get at the local Home Depot. In this case, I got my fitting plus two a friend needed for a similar generator install for about 2/3 the price (even after shipping) that the local electrical supply house could get them for, and they're nicer fittings than what the electrical supply house carried.
The final hook up was the grounding rod at the generator - the manufacturer requires a separate grounding rod to be installed at the generator and connected to a special terminal on the outside of the generator at the lower right rear corner. I bought a a fence post driver and used that to pound in an 8' ground rod behind the generator. The fence post driver is basically a heavy metal tube about 2' long with a heavy metal cap welded on one end. There are two handles, one on each side of the main tube, that run the length of the unit. You basically place it over the end of the item you want to drive into the ground, lift it up a foot or so, then ram it downwards. It's like a sledgehammer that's guaranteed to hit the target every time because of the tube. To make the install as easy as possible, I waited until the ground was soft from a few weeks of wet weather (otherwise known as December/January in the Seattle area) and the ground rod went in surprisingly easily. Simply spearing it into the ground got me the first 2+', and pushing it in by hand went another couple of feet. I was then able to stand on a ladder and safely use the fence post driver to drive the rod in until it was close to ground level and the ground rod driver was running into the ground. At that point the bottom of the ground rod was getting into drier and denser soil so it got harder to pound in the remaining couple of feet, but not impossible. Once I got the top of the ground rod down to ground level, I dug a small hole around the top so that I could get the entire grounding rod below ground level the required depth. For the ground wire hookup, I used some spare #4 AWG wire from the generator hookup and ran it in a trench from the back of the generator out to where the grounding rod was. At the grounding rod, I used a clamp rated for direct burial to make the final hookup. All in all, installing and hooking up the grounding rod was a reasonably simply process that took less than an hour to complete.
Generators and Your Broadband Internet Connection
An interesting point is that our DSL connection stayed up most of the times that we have been on generator power. I wasn't really pondering this until we got the portable generator installed, and then I tried it just for kicks when we on generator power - and it worked! How? The "central office" for the phone company (aka, where your phone and DSL line runs to) is generally both battery and generator backed so the phone continues to work in emergency situations, so the equipment there stays alive pretty much all the time - which includes the DSL equipment on their end of the line. This is important because as long as the phone line is not physically cut (say, due to downed trees), your DSL connection will generally work so long as your DSL modem has power. This means that a generator at your house will keep your DSL connection alive in most cases. On the other hand, cable modems generally do not work during a power outage, even if you are generator equipped. In the experience I've had so far (which has been confirmed by various folks), the cable company is much less resilient to power outages and your cable modem is pretty much down until power is restored, even if you are on a generator. Combined with the fact that the cable company does not hand out static IP's even if you want to pay for them, and well, my choice to go with DSL was pretty much sealed. Speakeasy kicks butt - they are, hands down, the best ISP I've ever had. Unfortunately, I eventually ended up going to Comcast business service (via a cable modem) to get a faster hookup. Dealing with their business class folks is much better than consumer class stuff. Static IP's, 24x7 support, and frankly, it was something like $10/month cheaper than my DSL was when I switched. Speakeasy was awesome, but they were constrained by the antics of the local phone company at every turn. Anyways, at least with my business class service, I've yet to see a power outage take down my internet access, but we haven't had an area wide outage of any significant length yet to test that theory out. We'll see how it goes...
I wanted to get a few things onto generator-backed circuits, one of which was my wireless access point in the hall closet. To do this, I added a new drop from an outlet in the den, into the crawlspace, and up into the hall closet. Not hard, just tedious. It takes longer to patch the drywall than anything else on projects like this... The paint match was pretty close despite having to buy a fresh quart of paint to do the touch-ups.
The hall closet end of the work. I had previously added a light in the closet on a switch, and an outlet in the hall (back side of the wall in these pictures) plus an outlet up high with a network tap for the wireless router, along with some new and improved wiring for the thermostat. This is roughly the center of the house/property so it works out well for range and signal strength, and tucks out of sight nicely. But it was all on the circuit for the shed outside lights and the crawlspace lights, and we used the outlet in the hall to run the vacuum. The thought of the vacuum motor sending electrical noise into my wireless router was an issue. So, I tapped the den circuit to power the top outlet in the closet and left the rest alone. Due to the previous work, I had un-patched sheetrock, with the cut-out sheetrock bits simply set back in place. That made it easy to do the wiring work - pull out the loose sheetrock, pull some wires and do the re-wiring, and I was done with the electrical bits. After that I patched the drywall. Unfortunately, I didn't get any pics before I patched the drywall, but you can see where the patches are in the first two photos. The primer is a much brighter white color than the existing wall color...
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Page last updated 01/15/2012 03:42:32 PM