Posted: 8/21/2012 5:50:01 PM EDT
|
My brother-in-law is making noises about a generator for his new house. I'd like to do him a solid and point him in the right direction.
I did a search and found many references, but nothing condensed. Does a tutorial exist? Help me Arfcom SF, you are my only hope! Thanks, |
|
Before you drop coin on a manual transfer switch, look at the APC UTS transfer switch. I think I'm about to pull the trigger on the 10 circuit model.
It will make running a generator in your home that is not big enough to run your entire home about as efficient as possible. It will detect surges and cut off lower priority circuits if a bigger load comes online. You can apply guidelines to these circuits, like running the refrigerator at least 45 minutes, etc. You can hook up an inverter or UPS as a secondary backup power source and program some circuits to be un-interruptable. We have frequent summertime storms that might make the power go off a few seconds or minutes. My cable DVR takes close to five minutes to reboot. During rough weather that can be a concern. The UPS (if you size it correctly) can handle those loads to keep them running long enough to get the generator fired up. Heck use it to power the lighting around your panel so that you don't have to find a flashlight. I'm thinking this generator will make the job as "wife friendly" (please note I did not use the term idiot proof  ) as possible in my absence.
http://www.youtube.com/watch?v=sBnve8XvN1s |
|
I'm an electrician and have set up a number of generator systems, from large transfer switch driven setups to simple backup systems for the home. The easiest and cheapest way is to simply mount a small panel next to your regular panel, connected with a conduit. Tehnically, by code, you should have 2 conduits, one for feeders and one for branch circuits, but we did it with just 1 a lot and I don't have an issue with it.
You pull say, a 50 amp two pole circuit off your main panel and backfeed the newer, smaller panel with a 50 amp breaker. DO NOT USE THE LUGS. Pull your ground and neutral from the appropriate busses (I say this because I have pulled off subpanels and main panels, the difference being whether the neutral buss and ground buss are separated, as they should be after the first point of disconnect. (Main panel.) Pull all the circuits you want to run with the generator off their respective breakers and extend them as nescessary to get them over to the new panel. If you buy the same brand subpanel you can just move the old breakers to the new panel. You do not need to move the neutrals or grounds. Typical circuits would be the kitchen circuit your fridge is on, a couple logical lighting circuits, the circuit for the furnace ignitor, and a freezer circuit, which if you are smart, will be on the garage door opener separately (not common) when you wire the house. A separate cold switch to turn of the garage door opener will prevent 'drive by' openers but of course the freezer should not be setup this way. Do NOT put your freezer on a GFI -motor loads can trip them, and it will only happen when you are gone for 2 weeks on vacation. Ask me how many times I've seen this. Now you need to run another conduit outside large enough for # 6 feeders from the generator. If the panel is mounted outside, you can just drop a WP 50 amp twistlock receptacle out of the new subpanel. Use a heavy grade, metal weatherproof cover NOT a plastic one. YOU MUST MOUNT THE GENERATOR BREAKER DIRECTLY ABOVE OR BELOW THE BACKFED BREAKER FROM THE MAIN PANEL. Both SQ-D and GE sell breaker kits (I'm sure CH does also) that are just a simple pivot that fits between the two feed breakers, the one from the service and the one from the generator. Flip either of the breakers in either direction, and the other breaker will be in the opposite postion, so that when the feed from the generator is on, the feed from the house is off. Now make up a 6/4 extension cord that runs from the generator twist lock to the subpanel receptacle. When the power fails, you have to actually go start the generator, but most of us have small ones anyway and can't afford remote start systems. Before you start the generator of course, you plug in the twist lock extension cord. One the genny is running, flip the genny feed breaker in the new subpanel on. Now the circuits you have chosen are being powered off of the generator but are still separated from the main service in case the power comes back on. Of course, you have to do the load calculations to make sure you have a large enough generator - if you do 30 amps it'll run most loads, but not a well. This is the cheapest way to set up a genny safely. ATS systems are expensive, and in my experience, represent more to go wrong in an emergency. I am setting up my place just this way. |
|
Quoted:
I'm an electrician and have set up a number of generator systems, from large transfer switch driven setups to simple backup systems for the home. The easiest and cheapest way is to simply mount a small panel next to your regular panel, connected with a conduit. Tehnically, by code, you should have 2 conduits, one for feeders and one for branch circuits, but we did it with just 1 a lot and I don't have an issue with it. What section of the code is that in? There is no code I am aware of that would prohibit a feeder and a branch circuit from being in the same conduit. Service wiring - yes. Feeders - no. |