Backup Generator
I have received some questions on my generator install since mentioning it on the shack page, so this will show how I installed my portable generator into my garden shed for a more permanent install.
When considering a generator I first started to consider what I needed to run. The main things I need, Heat, Lights, Refrigeration. I also planned for a few other conveniences such as cooking and entertainment. I have an electric cooktop and stove, and unless I bought a really large and really expensive generator I wasn't going to be able to run that. So the next best thing was to power the circuit in the kitchen which supplies the countertop outlets. By doing this I can run my electric griddle, microwave, coffee maker, toaster, etc.. I can cook an entire meal with small electrical appliances so that was taken care of. As for entertainment needs, its nice to put in a movie for the kids to keep them occupied, watching TV otherwise isn't a concern because if the power is out to me the cable system in town will be out as well, which means no cable television or internet service during an outage. Which also means no need for power to the computers.
The other factor is COST. What can you afford, and what can you afford to live without?? I spent roughly $600 on just the generator, sure it would be nice to have a whole house generator but consider the size and cost. Do you really need every single item that you normally use on a daily basis during an outage? My answer is no. I want the basics of daily life, I don't need the luxuries. The other factor is the larger the generator the larger the fuel consumption. I can run about 8-10 hours on a tank of fuel with average load, to have a whole house backup, I have figured roughly a 24kW generator to supply my 200a service panel, my fuel consumption would double if not triple. Sure you can run on Propane or Natural Gas but make sure if you go that route you have your own storage tank, don't rely on the city utilities. I have seen outages before where people with generators running off their city gas line had to go fight for a bottle at the local supplier because the city gas lost pressure as well. It CAN happen. Or have a generator which can run off Diesel or Gas as well as switch over to Propane/Natural Gas. This would give you more options depending on the situation. Another thing to think about, if your running just a regular gas powered generator like me then have the tank full after every use and at least 1-2 days worth of spare fuel on hand and treat all the fuel with Stabil to keep it fresh between uses. In my area when the power goes out the gas stations are out, if they don't have power you can't pump gas! Most of them have an emergency plan which involves hooking up a portable generator but they won't do that until its been out for a while, the last significant outage lasted nearly an entire day and they didn't get online with a generator and make gas sales possible until after six hours had passed, so plan ahead!
So now I had my list:
Heat - Consisting of electric baseboard heaters, I can run two off of the generator with enough head room on the generator capacity, this does require turning off other items but in a long emergency backup situation I have other lighting sources available if I needed to free up power for the heat.
Lights - Two circuits of the houses wiring which powers ceiling lighting and ceiling fans in most of the rooms was planned for, not every room has a working light on backup but most do and again I have other lighting sources, rechargeable lanterns and flashlights, etc.
Refrigeration - The last thing I need is a fridge of spoiled food! The refrigerator is going to be on backup as well. I also have a small chest freezer in the basement, but if well frozen it takes days if not a week for that to thoroughly thaw out so I wasn't too worried about it. If in an emergency which results in an extended outage I can run an extension cord to power it temporarily, and this would only really be needed during a summer outage. In the winter time here we have the whole outdoors as a freezer and I could easily go to coolers and snow to maintain refrigeration. Sound silly? Many have done it to keep food fresh during extended outages.
Entertainment - Power to the UPS which powers the entire home entertainment system in the house is easily accomplished with a short extension cord to one of the kitchen outlets that are on backup power. The main thing is I didn't want to overcomplicate things and the primary needs are to be on the transfer panel, if the outage lasts longer and I need power to the TV to entertain the kids that's a quick fix with an extension cord to the UPS.
Communications - The shack has battery backup for the radio equipment, but one circuit is on the generator transfer panel which provides lighting and power to the workbench area, never know what you might need to repair, or just tinker to keep you busy, during an outage so I wanted to make sure I had power for tools and other equipment in the shack. If the outage becomes an extended outage I can simply run an extension cord from one side of the shack to the other to power the DC supply and recharge the battery.
I figured out what I needed for Amps and also did the math to convert that to Watts for my modest backup. I selected a 5000W continuous, 6250W starting/surge Coleman Powermate generator due to knowing many people who have Powermate units. They seem to be very reliable for the money, affordable, and mine had the good old Briggs & Stratton motor on it. Some of the newer models have the Subaru motor. My only complaint there is I can walk into any hardware or auto parts store around here and purchase parts for the B&S motor, I can ever order a complete overhaul kit from the local auto parts store. But ask them about the Subaru engine and they look at you with a blank stare. I have heard the Subaru is a bit quieter and its reliable, but to me its parts availability and having grown up with Briggs and Tecumseh motors I wanted to stay with what I know.
Now lets talk about how to wire that into your house. First and foremost, you need a transfer switch in most cases, mainly because your local utility wouldn't be too happy if they found out your back feeding your panel. Its possible to do this if you have a Square D brand panel with the lockout on the main breaker, it only allows either the main or the generator breaker to be on, it won't allow both to be on. So why is this important? First of all if you back feed the grid chances are your going to kill someone working on restoring the outage! Secondly your going to end up blowing up your generator and starting a fire and most likely burning down your house or garage when the grid power comes back on and back feeds your generator. You need a safe way to switch to the generator! I went with a pretty basic transfer switch which suits my needs, allows me to transfer selected circuits to the generator as well as monitor the draw on the generator.
This transfer switch, which is the model I use here, allows you to connect six circuits, or bridge the center two for 240v leaving you four 120v circuits. It has breakers, the top row of switches, that protects the circuits when on generator power, and when your on grid power your breakers in your panel protect the circuits. There is a twist lock for the generator cord and Watt meters on each line from the generator. I did a couple modifications to my transfer switch which I will explain later.
The next consideration is where will the generator be when running? Obviously it can't be in the house due to carbon monoxide from the exhaust, and you don't want to toss it outside in the weather considering that chances are when you actually need it the weather is probably lousy to begin with. Around here the power doesn't go out unless its an ice storm in the winter or a thunderstorm in the summer, both conditions that I don't want it running outside unprotected. Also you have to think about security, a generator is worth its weight in gold when there is no power! You have to provide for theft prevention unless your going to sit nearby all day and keep an eye on it. In my case I had a garden shed in the back yard that would be perfect for this use. It keeps it out of the weather, the generator can be chained down to the concrete slab for security, the shed can be closed and locked to reduce noise, and it makes it safer to operate in general. However the exhaust is still something to contend with but I came up with a plan for that, more on that later.
So I know where the generator is going to be, now how do I get the power into the house and the transfer switch? Well a cord of course! I bought a 30ft heavy duty generator cord with twist lock connectors on each end. You can also go to your local home improvement center and get 10/4 cord and some twist lock connectors and make your own, and if you really wanted to you could also bury a run of 10/4 wire from the generator location to the house, that's up to you. For me I went with the cord. Sounds inconvenient to some I'm sure but its not, when I need it I simply grab the cord off its hook by the basement stairs and plug one end into the box on the side of the house and then the other end into the outlet box I installed on the side of the shed, by the time I get that done and fire up the generator and walk back to the house the generator is warmed up and I can now flip over the transfer switch and go to backup power.
Here is the generator Inlet box that I used on the outside of the house. This has a twist lock on the bottom of it and gets hardwired to the transfer switch.
The transfer switch I bought had a twist lock inlet built into the front, before wiring it to the breaker panel in the house I needed to address a few things. One was to take it apart to remove the inlet that it came with and replace that with a voltmeter to monitor the input, and the second was to make a knockout for a box connector to run wiring out the side of it which goes to the outside inlet box.
The inlet box has a male connector just like the transfer switch picture above, so the female end of the cord goes to the inlet box and that leaves a male connector to go to the generator, but I wanted a more convenient connection on the outside of the shed rather than having to pull the cord into the shed each time. So I went to the local home improvement store and bought a dual gang outdoor box, a twist lock outlet, and a weather resistant cover for it. This was the makings for a twist lock outlet to mount on the outside of the shed wall, from there I made a cord with a male twist lock to plug into the panel on the generator.
The next thing to tackle is the exhaust. I have run the generator with the shed doors open, but obviously this isn't the best option as exhaust still builds up in the shed and chokes out the fresh air supply to the engine as well as making it dangerous going in the shed to check on the generator or to fuel it up. So I started collecting parts to make an add-on exhaust pipe for the generator. They do similar things for generators on RV's and large campers, most of them use a special made exhaust adapter, here is an option that I saw on the web for welding an adapter to the original exhaust spark arrestor. You take the original exhaust off the generator and weld on a 2.5" to 2.25" (both measurements are inside diameter) exhaust reducer onto the face of it over the stock opening. This has the added benefit that you can still use the generator portable with that reducer on there or you can hook it up to your extended exhaust when running stationery.
Now that I have the connection for standard 2.25" exhaust components I bought two elbows, a flex connection, a length of exhaust tubing, a rain cap, and some clamps. If you have a local exhaust shop that can bend up the pieces for you that would work as well. In my case it was cheaper to just order all these parts online and then have the long straight piece of exhaust pipe made up locally, I had them flare one end to fit over the elbow and cut it to length. I also bought some antenna mast wall mounts for supporting the exhaust pipe on the back wall of the shed. If noise is a concern the stock spark arrestor isn't much of a muffler, its basically just a free flow arrestor at best, to quiet it down a bit a cheap high flow 2.25" car muffler would be a good choice. I find it isn't that loud with the exhaust pointed up, the noise is going away from you, but if you want to make it less noticeable just put a muffler inline!
Here is the exhaust stack on the back of the shed showing the mast wall mounts for standoff and support and the rain cap. The hole in the back wall was made with a 3" bi-metal hole saw to leave a bit of room around it, my shed is made of sheet metal, if you have a wooden shed your going to need to make a pass-through to avoid fire, something like a piece of stove pipe or even a piece of larger diameter metal ducting installed in the wall with the exhaust pipe centered in that to create an air space around it and provide shielding for the wood.
Here is the exhaust inside the shed, the flexible section or flex pipe as most exhaust places call it provides for movement of the motor without putting stress on the exhaust. The stock spark arrestor mounts to the motor on these generators not to the frame, so they move with the motor. If you just attached an external exhaust without any give to it you would eventually break the welded reducer or something worse.
The generator needed some more airflow for the summertime, and also in the winter when i want to leave the shed closed while running. The installation of a louvered exhaust fan took care of the heat buildup in the shed. When the generator is running the fan is running, when i shut off the generator the fan turns off and the louvers close keeping it weathertight.
That's it! I now have generator backup power when needed! Make sure if you have a generator, portable, permanent, or otherwise, that you exercise it monthly! I run mine once a month and check the fuel and oil levels, usually the first Weds of the month when I hear them test the tornado sirens, for 10-15 minutes and place a load on it consisting of two 100w light bulbs, one light on each side of the generator output. If you don't you could end up with a dead generator when you really need it! Most don't realize that leaving it sit is not only hard on the engine but the generator head itself, you could end up with one that needs the field excited, not a problem when you got time to work on it, but in an emergency it could be a major inconvenience!
I've had some questions on exciting a generator. After doing this myself on an old generator that was sitting for years here is how I was told to do this and it works!! The things you need... A corded drill, a cordless drill, a piece of metal rod or a long bolt with the head cut off, a work light or lamp. Plug the corded drill and light into the generator, take the piece of metal rod or cut off bolt and fasten it into the chuck of the corded drill on one end, and the cordless drill on the other end, of course you can do this with two corded drills as well if you happen to have a power source to power that other drill. Start the generator and let it run a few minutes to warm up. Depress the trigger on the corded drill plugged into the generator and then depress the trigger on the cordless drill to spin that drill, basically your turning the corded drill into a mini generator to push power into the generator. You should see the light start to light up, when the light comes up to full brightness release the trigger on both drills and let the generator run. If the bulb doesn't start to light try running the cordless or second drill in the opposite direction and do it again, I had to play around with the drills to get it to feed back correctly. If the light remains lit then you successfully excited the generator, put a load on it and monitor the voltages for a while to make sure everything is ok.
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