Generator Wiring Question.

[JSUnlimited]

Late last year a recieved a few quotes from several electricians for installing a manual tranfer switch so I can eliminate running cords all over the place when the power goes out. The prices ran from $800-$1200 for a manual transfer switch install!!! None of the four electricians had the same plan either.

Today I get the interest again, thinking I can do this myself, I checked out the products on this site:

Reliance Controls

These look easy to install and can be bought cheap from various places.

Then I think, why can't I just put a 30amp double-pole breaker in the panel and feed it from the generators 220v/30amp outlet? As long as the main is switched off during outages and high amp items are shut off? It's cheaper this way and I'm not limited to specific circuits.

I don't want to kill someone, and I've read about the neutral bonding issue. Why would'nt it work?

 

[5030]

Look at it this way. If you do it yourself and it don't work, you MAY turn your house into a large TOASTER. /forums/images/graemlins/grin.gif

I had a certified electrician do mine and there are 2 grounds a common ground and a mechanical ground.

 

[beenthere]

Seems what will work is anything that will disconnect the power company line from your service box.

Years back, when I went from farm to farm with a gen set on a trailer, I'd pull out the meter from its socket and connect to the farm (or house) side of that socket. Shut off all un-necessary circuits so the 10k genset could take the load, and first get the milk cooler going, followed by the compressor to milk cows, followed by the pump to water the cows, and then turn on some circuits to the house to get the freezer and refrig running. When all was 'caught up' and a supply of water pumped, we'd pull the wires and plug the meter socket back in (then let the power company hopefully get power running again).
In a weeks time, a neighbor and I worked most of 24 hours a day for 7 days after an ice storm. Once we found a meter wired upside down, but didn't kill anyone on the power lines by trying to feed the 10k back out from the meter. That is a problem, and I regret we made that mistake. Just killed the genset when we tried but it wasn't good.
For me, before I would do anything, I'd pull that meter out of its socket. That way no harm can take place off the premise.

Tripping the main breaker for the service entrance should do the same, then hooking to the two buss bars that the breakers are snapped to should also work, tripping off all breakers to start with and turning on only the ones needed (like refrig and freezer, after the toilets are flushed).

 

[cisco]

As you suggested works. I've had such for a decade. You need to cut OFF the main breaker, so you don't feed power to the neighborhood (and harm someone). I just put a double pole 220 v breaker in my main panel, and connected it via #8 wire to a 220 plug located within a foot of that main panel. Works fine. As noted, you must turn off amp-intensive feeds from your main panel (mine are a central air conditioner, and a water heater) before you flip the breaker connected to your generator. Mine is a 6500 watt Honda.
Now, on my more recently built country garage/apartment, I had the electrician wiring the place put in a subpanel off the main panel that contains only breakers for the water pump, refrigerator, and 1 light from each room. I've a 3500 watt Honda that works for such, and it plugs into a 220 socket located beside the subpanel, and when the switch is thrown on the subpanel, the switch to the main panel is turned off. The water heater and stove are propane.
So, the homemade set-up cost about $100, and the electrician's about $600 - both work, but I'd much rather have a houseguest (or my kids) use the electrician installed unit, as it's "idiot proof" - you don't have to switch off anything to get it to work, and safely.

 

[nobull1]

I had a panel installed at both the house and barn. My experience is that once you know how it should be done you wouldn't do it otherwise. As far as the price goes it wasn't cheap to have mine done . I am surprised that the electricians didn't have plans that were close to each others. In Nova Scotia the power corp has a detailed explanation of how to do it. They also say it is the only way to do it. The problem is it is simple to do just throw the main breaker then turn on what you need. The power corp has a problem with this though as they are putting the lives of the linesman at risk by hoping you remember to throw the switch. Although this seems simple you have to remember you won't do this often and have to do the procedure in the correct order.Also if you are not at home and someone else has to do this are you sure they would do it right? To activate a transfer panel the main panel has to be disconnected.When the transfer panel is correctly installed it is just a failsafe. I don't believe it is worth the risk but most people in our area do it illegally and hope nothing ever goes wrong. Another issue might be your insurance co and liability. I bet if you called them it would not be a good conversation . If you want to go the illegal route you can pm me and I can tell you how to power you whole house[selected circuits] for less than $30.00 plus the generator cost. Obviosly it would be irresponsable to post how to do this and I will not tell everyone who pm's me so don't bother.

 

[Shimon]

There are a couple of problems with just shutting off the main breaker to run a genset. First off is human error. There is no fail safe way to ensure power is shut off. You need to remember to do it and someone can come along and flip the big circuit breaker on without you knowing which can send power down the power lines which can kill someone. In addition, even if you ensure the main CB is off...your neutral is still connected to the power lines because only the two hots go through the CB. So, if your grounding system isn't up to snuff then if you have a short to ground then you may still send power while on the genset to the power lines and harm some lineman working out there.

Now, that being said...I'm guilty of not following my own advice. I have a generator hard wired into my system and I shut off my main CB to isolate. But I keep my generator panel locked when not in use and when I use the generator I lock my main panel so someone can't turn the main CB back on. It's still not fool proof and I can screw things up like anyone else. Also, I've recently upgraded all the wiring in my home and I have new, solid grounds and I check for faults going down the neutral and ground once in a while.

As for pulling the meter...I think that pisses the electric company off. They put those tamper tags on there for a reason. If the meter has been pulled, they have no way of knowing if you've been stealing power by jumpering the terminals. I would check with the electric co before pulling a meter.

As for having an electrician wiring in a manual switch...it depends on what you want. If you only want a couple of circuits to run while on the genset then you just need to remove those circuits from your breaker panel and feed them from a sub-panel which can then be switched between genset and main power (and it switches the neutral too). Or if you want to have your whole house run on a genset then the switch needs to be between your main CB panel and the meter. It can be done a couple of different ways depending on what you want.

 

[Spiffy]

From the human error....to: doing it anyway....to: make sure the ground is good.

Well put!

Couldn't tell you either way about the power companies and meters, but since I always have to be the contrarian and just use the main breaker...never even thought about pulling the meter or what they'd say if I did! /forums/images/graemlins/blush.gif /forums/images/graemlins/grin.gif

 

[beenthere]

Pulling the meter may 'PO' some power companies, but I have never had ours complain in the 45 years that I have been doing it. The seal remained off mine for several years, with the meter reader looking at the meter once a month. Now they read the meter by driving by in their pickup with remote sensor.
I suggest it only as a fail safe way to protect their linemen, and don't worry about whether it gets the power company PO'd at me. /forums/images/graemlins/wink.gif

Along the same line, I recently added a 200 A service, and the building inspector insisted that the 'new' code requires a disconnect within 10' of the meter, reason given so the firemen can quickly locate where the power to the house can be shut off. Hmmm? I wonder why they don't just pull the meter from it's socket? Would be quicker, safer, and save them trying to find the disconnect in a fire. Further more, another code requires the service to be behind a fireproof 'door', so I had to put a drywall door over the service which is the 'disconnect' that the firemen will be looking for 10' from the meter. Go figure that one out. I couldn't and couldn't talk any sense to the inspector either, so I 'hid' the disconnect behind the drywall. /forums/images/graemlins/tongue.gif /forums/images/graemlins/tongue.gif /forums/images/graemlins/tongue.gif

 

[Bird]

I think most power companies won't complain if you let them know when you're going to pull a meter and why. When I bought my place in the country, the meter was on a pole that was rotting, and there was a 100 amp master panel right under the meter. Fortunately, they had used the proper wire from the weatherhead down to the meter for 200 amp service. So I set a new pole next to the old rotten one, bought a new 200 amp master panel, and called the electric co-op and told them I was going to pull the meter the next day to move everything to the new pole. They were quite unconcerned about it.

 

[Hootie]

Recently had a 15kw Generac installed. I shopped around and saw the do it yourself kits. After having it installed by a competent electrician, I am really glad I did not attempt this myself. I watched them install and there are just things you gotta know. The peace of mind is worth alot, in knowing it is going to work and not back feed. I cannot believe that anyone without a THOROUGH knowledge of electricity would attempt this.

 

[techman]

First of all, as stated, a transfer switch is to prevent any possibility that the generator and utility power are never interconnected. If a utility worker is on a pole near your house to fix an outage, and you accidently backfeed the power line, the pole transformer and wiring could become hot and kill the guy. A transfer switch is required by code.

As for transfer switches, the full load switch is quite expensive as you learned. The one you saw (with your link) will transfer a limited number of circuits and is lower cost. This allows the critical circuits to be powered up. Installing one is not beyond the capabilities of a DIY'er who has installed new circuits and breakers in a panel.

The other thing to look in to is a main panel by Square D. They make a normal panel that has the provision to have a breaker that can be connected to the generator to backfeed the entire panel, as you mentioned. The difference is that there is a mechanical interlock lever that does not allow the main to be on when the generator breaker is on and visa versa. It may require replacing your breaker panel to use this one, but that may be a not too unreasonable price in the end.

paul

 

[Justaplain]

I have 3 double pole/double throw wall switches in series with the panel and load.. One pole to gen set and one pole to the service. One is wired to a 240 pump and the other two to freezer etc. They cost me less than 10 bucks per. bcs

 

[George2615]

I have a manually switched set up for my generator. My generator is a Hobart 250 NT welder/generator rated for 10KW and has a 50A 220V receptacle on the front. I have two electrical panels so I installed a separate main knife switch disconnect in my garage that feeds a panel in the garage and the one in the house. In the garage panel I installed a double pole 50A breaker and fed out a flexible 4 wire lead cord (2 hot,1 neutral,1 ground) and put a 50A male plug on the end. I also mounted a dummy 50A receptacle in the wall by the panel to plug the whip into when not in use. When I lose power, I roll the generator outside the garage door and fire it up. While its warming up I verify the main disconnect from the street power and my 50A breaker are both turned off. Then I unplug the whip from the dummy plug and insert into the generator. At that point I turn on the 50A breaker which then feeds power back into the house. All I do then is watch the neighbors house for signs of street power being restored then reverse my steps to go back to normal power. I typed up a step by step procedure check list to follow and it is posted next to the panel so if I wasn't home anyone could follow the procedure to have house power.
Anyone with a basic knowledge of electricity should be able do this. If you are unsure then hire someone who is knowledgeable. Just be sure the breaker and lead cord you install are rated for the amperage of your generator. I see no need to pull the meter if you have a main disconnect switch. Your 30A generator may not run all items in you house so you may have to be selective and turn off some additional breakers. My previous generator was 5KW w/ 6250 surge and had a 30A plug on it as well. It did a fair job but I shut off many non essential breakers while using it. As some others have said, there is a fully automatic system that will not allow generator power to backfeed into street power. If you have an auto start generator you need an automatic transfer switch. If you have a manual start generator you are responsible for ensuring that your power does not backfeed street power. There is always a chance for human error that could injure or kill someone.

 

[1962]

i pull the meter too. been doing it since the early 90's. i cut the seal wire with wire snips. and replace it when power is back on-grid. the power co wont really take notice unless they start seeing a huge loss per month in your electric consumption. like if i was stealing electricity. i also disconnect the main at the panal. the panal is well grounded, and the generator is earth grounded at it's outside location. the meter socket is about 5' off the ground and i pop a plastic guard over it for safety, and for freezing rain if its winter.
#1 pull the meter and cap it
#2 fire up the genny and let it warm up
#3 select the circuits i want to power at the panal
#4 plug in the genny to house disconnect(main line)
#5 throw the genny power to house switch

 

[VA_Joe]

techman makes good sense.

Use a mechanical interlock to ensure that the mains and gen power are never connected. Not using one could result in both death to a lineman and a manslaughter charge to the person that didn't follow established code (it is no different than killing someone while driving drunk). It's not worth ruining two families over a $50 switch.

BTW - I use the 60 amp Square D mechanical interlock along with a second subpanel for all the generator circuits. The advantage of the 60 amp box (over the 30 amp) is that it gives you more control over which circuits to run at any given time on generator (i.e. even if you have a 30 amp genset) but still supplies more than enough capacity for running all circuits off the mains.

Joe

 

[nobull1]

BTW - I use the 60 amp Square D mechanical interlock along with a second subpanel for all the generator circuits. The advantage of the 60 amp box (over the 30 amp) is that it gives you more control over which circuits to run at any given time on generator (i.e. even if you have a 30 amp genset) but still supplies more than enough capacity for running all circuits off the mains.



I agree, when I had mine installed that was a question the electrician asked. At the time I didn't realize that a 60 amp would give me access to a lot more circuits that I could potentially use. One thing though in our area is if you go to a 60 amp you have to have a manual disconnect switch installed in line. Why I don't really know but that is code.

 

[Shimon]

Hmm...that's interesting about the electric companies not caring too much about pulling the meters. I'll have to call PSE to see what their policy is. Learn something new every day (especially on TBN).

 

[QRTRHRS]

The automatic stand alone systems need to have the feed from the meter to the box changed. It has to run through the transfer switch then to the box. The meter must be pulled and the hot leads to the terminals must be respected. Those systems are slick, the genset can be set up to run periodically. The only drawback is most electricians are not all that well vesed in the genset engine maintanence.

I have not seen one but I think Square D has some kind of breaker that you can wire into to reverse feed. The breaker isolates the box somehow? But then you would need a Square D box.

One of the safest ways for someone who capable of working inside the box but does not want to pull the meter,etc. is to go with a manual transfer switch. With a manual switch, depending on the size, you choose your most important circuits. Each switch has two wires. You remove the hot from the breaker, wire nut that to one wire then secure the other to the breaker. The switches have three positions, line, off or gen. Normally on line, when the power goes off, you fire the generator up, then throw each switch to gen.

The wire from this type of switch takes up a lot of room in the box. If your box is already stuffed, it may be time to upgrade anyway. And, although simple, explaining the procedure to my wife is like teaching her to program the VCR.

Your local codes may have a say in what you do when you set up a backup system.

 

[Jagmandave]

Why not use a simple either/or switch rated for your main panel?

When you're running on line, it's in that position, when you pull it into the gen position, you're disconnected from the line. Then all you have to do is make sure you're not overloading your genset on startup, by throwing your heavy load breakers off. Seems simple enough to me......

It also acts as a service disconnect in the middle "Off" position

 

[QRTRHRS]

Would that not involve pulling the main and rerouting the feed for the installation?

The beauty of the manual transfer switching is that you initialize one circuit at a time. That and someone with an average knowledge of electricity to do the install.

By the way, not that it is any big deal for the average home owner but the self starting gensets with automatic transfer are hardly transparent. There will be a momentary "glitch" until the genset takes over.