Generator question (household wiring to be more accurate)

[Threepoint]

Legality is a matter of local code. I know many jurisdictions allow an approved "lockout" device on the breaker panel in lieu of a transfer switch. HOWEVER, I always thought that the lockout device had to be from the same manufacturer as the panel, e.g., Square D, Murray, Siemens, etc. The KirkKey interlocks that Aaron links to are new to me. I would sure check with the local inspectors' office before trying to use them for a residential panel backfeed application.

 

[aczlan]

but if you back feed the house and some one screw up and energizes the power line and kill a line man, it will not be so good, it is illegal to set up a hook up like that,

do it right or do not do it at all,
use a transfer switch that is approved,

That's the point of the trapped key interlock. You have a lock on the main breaker and its mate on the generator breaker, they are installed so that it is physically impossible to turn on the breaker when the lock is locked and the key is removed.
It is physically impossible to remove the key until the lock is in "locked" position (which requires that the breaker be shut off. As such, you cannot turn the generator breaker on unless you have the key from the main breaker. To get that key, you MUST shut down mains power and lock it out (by removing the key) before you can turn on the generator breaker.

They are used all the time in industrial applications to keep people from frying themselves by skipping a step. This is what they were designed to do and what they do every day.

Aaron Z

 

[buickanddeere]

Very interesting Aaron, i didn't see any pictures of them in service panels but it sounds like a logical solution. would this system be acceptable to the safety police?

I don't know why the disdain for the safety police. "They" are taking their own time and resources to try and convince you and others to not maim, cripple, kill or set fire to property. That is hardly mean spirited, in particular when the safety police receive mocking and disdain instead of thanks for caring about you,your family and electrical crews.

 

[Dutch445]

I don't know why the disdain for the safety police. "They" are taking their own time and resources to try and convince you and others to not maim, cripple, kill or set fire to property. That is hardly mean spirited, in particular when the safety police receive mocking and disdain instead of thanks for caring about you,your family and electrical crews.

agree with your comments, i was wondering what other input people might have on that system, and whether
it is acceptable practice or within code to use. i had never seen it before, although i realize there are several
styles of industrial lockout systems.

 

[buckeyefarmer]

Used to use kirk keys on high voltage switches

 

[buickanddeere]

agree with your comments, i was wondering what other input people might have on that system, and whether
it is acceptable practice or within code to use. i had never seen it before, although i realize there are several
styles of industrial lockout systems.

Our old ITE 600V switch gear at work used the kirkkey system if the A & B buses were connected via the tie bus. Then depending either the A or B bus supply breaker was locked open. Providing isolation from a secondary side back feed while we were working on the supply transformer . The kirkkey has it's place but it's not the first choice for a typical service entrance generator transfer switch. Nothing beats the break before make transfer switch.

 

[MossRoad]

So to recap, you have a 6/3 with ground wire running to the subpanel?
If its not feasible to run a new wire from the main panel to where the generator is located, I would look into a Kirk Key type trapped key interlock system such as: Lot of 2 Kirk CK43670 Key Interlock with Key | eBay
View attachment 456392
Then one goes on the main breaker and the other goes on the generator breaker in the subpanel. The way it works is that in order to get the key out, it needs to be locked (with the rod on the lock extended).
In your system, you install one on the main breaker (so that the rod can only extend if the main breaker is off), and the other on the generator breaker (so that the rod can only extend if the generator breaker is off).
Then to switch, you shut off the main breaker, lock the main breaker interlock, remove the key, walk over to the generator breaker, unlock it and turn on the generator breaker.
The 2nd set of keys is to be stored in a safe place marked for what they are for and marked that only one set is to be used at a time.

Aaron Z

We had this discussion back in 2014 and I was waiting for you to implement because I wanted to see how it turned out. You gave a very good explanation as to how it worked back then. And I wanted you to be the guinea pig, too! :laughing:

Here's a link to your great explanation....

http://www.tractorbynet.com/forums/...de-building-powering-panel-6.html#post3927271

 

[aczlan]

The kirkkey has it's place but it's not the first choice for a typical service entrance generator transfer switch. Nothing beats the break before make transfer switch.

That's all well and good if you have a generator in the "typical location" near the service entrance, but what would be the downsides to using it for a non-typically located generator (like the OP is looking to setup)?

Aaron Z

 

[aczlan]

We had this discussion back in 2014 and I was waiting for you to implement because I wanted to see how it turned out. You gave a very good explanation as to how it worked back then. And I wanted you to be the guinea pig, too! :laughing:

Here's a link to your great explanation....

http://www.tractorbynet.com/forums/...de-building-powering-panel-6.html#post3927271

I will have an electrical inspector out soon and I will ask him about it.

Aaron Z

 

[MossRoad]

I will have an electrical inspector out soon and I will ask him about it.

Aaron Z

I appreciate it. :thumbsup: