Emergency generator feed

[oldgoat]

We had the power go out for over 24 hours and some at work were saying that they were turning off the main breaker and just plugging the cord from the generator into a socket to run what they wanted in the house. I was told that you shouldn't do that because in some cases it can still back feed into the grid and possibly hurt the electrical worker that is trying to get power back. However one guy asked the electrician that came to his house to restore power and he said that as long as you have the main breaker off it is OK to plug the generator into the house outlet to get power. I'm just curious of what the real dangers, if any, there is.

 

[Alchymist]

Lots of threads on the web about this. They don't call it a "suicide cord" for nothing. Just google "suicide cord" - you get : About 11,900,000 results (0.06 seconds)

About now there should ooze from the woodwork someone to tell you it's ok, they have done it for years. Just read through the google lists and decide for yourself.

 

[Worsedog]

Yes it will work.

No you shouldn't do it.

You could possibly backfeed the power lines and kill the linemen working to restore your power. That is why a transfer switch is the proper way to do it.

I can see another PVC airline thread starting..........

 

[ishiboo]

We had the power go out for over 24 hours and some at work were saying that they were turning off the main breaker and just plugging the cord from the generator into a socket to run what they wanted in the house. I was told that you shouldn't do that because in some cases it can still back feed into the grid and possibly hurt the electrical worker that is trying to get power back. However one guy asked the electrician that came to his house to restore power and he said that as long as you have the main breaker off it is OK to plug the generator into the house outlet to get power. I'm just curious of what the real dangers, if any, there is.

It's safe in principal.

IF you never turned the main breaker "on" with the generator hooked up, AND nobody ever worked on the system assuming the panel was not fed from two sources (which requires a specific label according to code, I believe, if not it's strongly suggested.), everything would be fine.

The issue is, if for some reason yo forgot to turn off the main breaker, or turned it on with the generator running, you could kill a lineman, or multiples of them, who think they're working on a de-energized circuit.

To me, the risks far outweigh the benefit. It's easy to install a mechanical interlock (and relatively inexpensive) if your wish is to back feed the panel from a breaker. (The breaker still protects operating "backwards", nothing unsafe about it in general.) I don't want to be responsible for killing someone.

If you were working on a circuit you energized, would you like your life hanging on the line from the assumption that a main breaker in someones house using illegal wiring could kill you?

IMO, don't do it.

 

[D.J.]

Went to a electrical safety class just last night (FD Training) by LIVE LINE DEMO and this was discussed at length. The Journey lineman Kyle Finlay (sp) putting on the class said that the transfer switch was about $400 or less for the 200 amp services. I really think that if you can afford the generator you can afford the UL listed transfer switch it takes to make it legal. Why not just run the major appliances off of heavy duty drop cords plugged into the generator directly? Judt my $.02

 

[NWOhioChevyGuy]

You can also put in a generator meter socket, this has a two feed system (double breaker) with an interlock so Main feed and Generator feed can not be on at the same time.

Much less expensive to purchase and install.

I purchased mine from my power company for around $200.

 

[Jack Olsen]

You're getting some good advice. There's a reasonable chance that, sooner or later, you -- or someone in your world -- will flip the main at the wrong time.

 

[Norcal]

You can also put in a generator meter socket, this has a two feed system (double breaker) with an interlock so Main feed and Generator feed can not be on at the same time.

Much less expensive to purchase and install.

I purchased mine from my power company for around $200.

That will depend on the PoCo, they all have different rules & standards,but a genny backfed w/o a transfer switch is prohibited by all of them.

 

[NWOhioChevyGuy]

I agree, that is why i went to my power co for the approved options.

 

[ishiboo]

That will depend on the PoCo, they all have different rules & standards,but a genny backfed w/o a transfer switch is prohibited by all of them.

Isn't an interlock a form of a transfer switch? It mechanically prohibits the two from being connected together. I doubt on a main panel the poco has much say or cares if you're using a mechanical interlock. "Prohibited by all of them" is a pretty assuming statement. I'm sure many permit main breaker interlocks without a double throw transfer switch, especially on portable generators.

 

[ishiboo]

BTW, outside the context of this thread, but since I've never played with solar, what requirements are in place for a grid tied solar system (or generator or whatever)? The PoCo regs I read, just a couple samples out of many, do not require a transfer switch with a paralleling generator. I'm guessing a lockout-tagout compliant switch is required on the outside of the house, or they pull the entire meter when servicing? Or, perhaps a pole disconnect must be added for houses which purposely back feed. Must be a ***** to keep track of.

 

[mrb]

grid tied solar has to have a lockable disconnect switch, plus the grid tie inverters shut down when grid is not present, but the disco is still necessary to make it safe -and someone could always get their inverter into island mode.

 

[5lima30]

+1 on get a properly installed transfer switch, you will NEVER regret it!

 

[Milton Shaw]

The thing that kills linemen is that the power transformer on the pole works both ways. It steps 7000 volts down to 240, and steps 240 up to 7000 when the grid is dead. That's what kills. So you must use transfer switch or you could kill someone.

 

[kbs2244]

The VFD guys I hang around with tell me that when the see solar panels on the roof the first thing they do take an axe to the wires from them.
Then they go pull the meter.
They don't like live wires with all the water they have around.