Wiring a portable generator
After the most recent, days-long power outage my wife made me buy a portable generator. I purchased one of 5000 watts (she wants to run a refrigerator, chest freezer and a couple outlets in the kitchen just to plug-in a reading lamp at night. We have a wood stove for the winter and city water.)
I want to make it convenient to use, so my plan was to add a sub panel, next to the main box, which would have two 20 amp breakers. These would be cabled to an identified outlet box outside the house where I could plug-in the generator, using double ended extension cords. I would run ‘jumper wires’ from the load side of four breakers inside the main panel that I wish to use during an outage to the two breakers in the sub panel (these breakers would normally be off, of course). During an outage I would turn the three main panel breakers off and turn on the ones in sub panel. With the generator running the flow of power would be into the sub panel then to the load side of the four main panel breakers and on to the kitchen. All this would be well marked to avoid inadvertent use.
I felt I had everything worked out, but then I thought about the neutral wire. What do I do with the neutral returning from the generator? Should I run these neutrals through the sub panel to the neutral bar in the main panel? This would seem to be logical, but is there a problem if the system is active when power is restored? I want to do this correctly, to avoid accidents or hazards to anyone. I have done quite a bit of wiring over the years, but never anything involving auxiliary power generation. I’d appreciate your opinions. Thanks.
Replies
Careful.......
There are special "kit" with full disconnect switches that must be used with this scenario so as to make sure that you cannot "backfeed" a util co transformer. It kills the connection of your main panel box to the util co.
If backfeeding happens......the transformers will step up the voltage, and send it down the line.....any lineman working on that line will be killed.
P L E A S E hire a competent electrician to do this install for you.
'Pickings' is right on the money. DO NOT DO THIS - hire an electrician. Even tho you may have done ' a bit of wiring over the years', your Q shows you aren't capable. Sorry to be blunt.
All the best...
To those who know - this may be obvious. To those who don't - I hope I've helped.
In addition to what the others have said you have another dangerous point.
"These would be cabled to an identified outlet box outside the house where I could plug-in the generator, using double ended extension cords."
That would give you a hot male connector on one.
You can get male receptacles and then use a standard extension cord with a male connector.
While not common they are available. Used for example on RV's.
talk to 4lorn, we had this discusion here about last nov. this is very dangeours. it can backfeed and kill people working on the lines miles down the road. alot of places illegal.
I agree with most of those who posted here. You don't need advice you need to hire an experienced electrician and get this inspected before you even think of firing this up. This is potentially very dangerous to those who will be working on the lines while power is out.
This is one instance where an attempt to save money, by doing it yourself, could put you into some serious liability situations. If you don't want to be retired, broke and on the street because of law suits then stop doing this on your own and get it done by professionals.
What you are doing is definitely against all known building codes. The only thing you could do safely is fire up the generator and use long extension cords to power your appliances during the outage, completely disconnected from house wiring.
Yea, hiring an electrician is exactly what I've been thinking, the further I have gotten into it. I was posting as a double check, and last ditch hope I was okay. The same storm that pricipitated the buying of a generator also wiped out my old computer (through the cable connection), plus I'm in the middle of a $2ooo.00 tooth implant. But, I do know when to hold 'em and when to fold 'em.Thanks to everyone responding.
That is a heck of a storm to knock your tooth out!
There was a time when I would not have considered spending $2000 on anything, let alone one tooth. But I already paid for a crown on it, and a root canal for it about twenty years ago. It seems crazy to yank it out now. My dentist said, "just be glad it's not your liver!" But I told him if it was my liver, it would be covered!
Thanks to all for your good advice on my little project. I did read the link to PM on the right way to install, but for now I think I continue to use extension cords. That is unless we have more than a couple multi-day outages per year. The aftermath of the latest storm, about a month back, left roads closed for days and hundreds of trees down. Many homes had blue tarps on their roofs, some still do. The power company, AEP, brought in help from two states and used helicopters to find the problem areas. I think it's time to either move underground, or move the utilities there.
Everyone has given you good advice, it's probably best to hire this job out. To show just what's involved, here is an article from Popular Mechanics that does a good job of describing how to install a manual transfer switch, a subpanel, and the appropriate connectors for use with a portable generator. If nothing else it'll give you a good idea of what's involved and why.
http://www.popularmechanics.com/home_improvement/home_improvement/1275631.html
There are two reasonable ways to go. Whole hog with the transfer switch, or just leave all the house wiring alone and run extension cords. Consider the number and duration of times you'd need the generator, getting or storing the fuel to keep it going, etc. Personally, I'd just run extensions.
-- J.S.
This is typically what we install when we aren't putting in full blown systems with an ATS. Put an inlet box on the ext wall run 10 gauge wire to the panel and wire it in. Turn off all breakers, and then only bring up what you need.
http://www.interlockkit.com/
Edited 7/19/2006 8:04 pm by dutchblue