Installed Transfer Switch in House

[jeffcrum]

I believe that the generators (with bonded neutral) that Generlink lists as OK only have the GFCI protection on 110v generator outlet i.e. not the full panel including the 220v. The issue with the truck is that the GFCI protects the 220v outlet and so this outlet will have an issue with the second bonded neutral in the electrical panel

I have put the question to them in email. I also invited them here if they want to come and discuss it with us.

We will see.

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[KGB81]

Ok this is the first information that makes sense to me. GFCI work by measuring the differential between the line current going out and neutral current returning. Any difference bigger than about 5mA and it will trip.

So if you hook the truck to house panel, the circuits get the power from the truck but then the return current on the neutral shunts to ground at the panel's neutral to ground bond. The truck effectively sees a ground fault.

I believe that the generators (with bonded neutral) that Generlink lists as OK only have the GFCI protection on 110v generator outlet i.e. not the full panel including the 220v. The issue with the truck is that the GFCI protects the 220v outlet and so this outlet will have an issue with the second bonded neutral in the electrical panel

 

[chrisp993]

So if you hook the truck to house panel, the circuits get the power from the truck but then the return current on the neutral shunts to ground at the panel's neutral to ground bond. The truck effectively sees a ground fault.

Yes! That's exactly my understanding. But I'm not an electrician so this understanding is ... limited

Tireman's setup earlier in this thread is a straightforward interlock which I thought breaks the live but leaves neutral/ground at panel unchanged ... in that situation, and for the reason described above, I don't understand why the truck doesn't show GFCI fault.

 

[jeffcrum]

Fireman's setup earlier in this thread is a straightforward interlock which I thought breaks the live but leaves neutral/ground at panel unchanged ... in that situation, and for the reason described above, I don't understand why the truck doesn't show GFCI fault.

Totally agree. But, there wasn't a discussion on how the incoming plug was wired.

 

[chrisp993]

Totally agree. But, there wasn't a discussion on how the incoming plug was wired.

I'm confused by your comment ... there are a number of posts earlier in this thread on how the issue can be fixed by cutting wires in the incoming plug (or similar approach) and I was just relating your issue and that earlier approach - there is the same underlying question of how the GFCI on the truck behaves with multiple paths to ground.

 

[jeffcrum]

I didn't think Fireman went into detail on his setup.

Agree that it has been discussed.

 

[jcaspar]

Will something like this work? Wouldn't be too hard to install but would make the main panel a bit of a mess.

 

[jeffcrum]

Will something like this work? Wouldn't be too hard to install but would make the main panel a bit of a mess.

Yes, it will work. I prefer an interlock. Generally cheaper and more flexible.

 

[jcaspar]

Yes, it will work. I prefer an interlock. Generally cheaper and more flexible.

My understanding is an interlock will NOT work due to the bonded neutral in the truck. Interlock would be much easier.

 

[jeffcrum]

The interlock is nothing more than a way to keep main breaker off while generator breaker is on and vise versa.

The wiring is separate. Wiring will have the same issue with what you linked. That is all in the hookup.

 

[jcaspar]

The interlock is nothing more than a way to keep main breaker off while generator breaker is on and vise versa.

The wiring is separate. Wiring will have the same issue with what you linked. That is all in the hookup.

I guess then the question is how is the hookup done?

 

[jeffcrum]

Keep in mind, I am not electrician and am not giving electrical advice. I am having a theoretical discussion.

If your ground and common bars are connected in your breaker box:

You could do what some have done here. Read back through and see about not connecting one of the wires either at the cord end or in the box.

If you want to do it the ... Ummm, other way I guess:
The device you linked will not help. It just extends your boxes wiring out to another box and inserts another switch basically. The connections will still be neutral bonded on the box and at the generator.

Since you cannot break the bond at the generator, you will need something like http://www.reliancecontrols.com/Products.aspx?pl=x_series&c=&f=

A good explanation of why https://diy.stackexchange.com/quest...generator-to-main-breaker-panel/177456#177456

Basically, this box actually separates the circuits completely from your main box when you flip the switch including the neutral and ground over to the generator side.

 

[jeffcrum]

After reading a bunch more, I am thinking more and more that the unconnected ground is fine and the interlock is really the way to go.

If I owned my home, I'd certainly do it myself. But, I rent my house. So, to get permission from the owner, I have to use an electrician. I am hoping they agree!

Again, not advice ?

 

[jcaspar]

Wow. So is sounds like it is actually pretty simple. Install an interlock, a generator power inlet box and disconnect the ground wire in the cord from the truck to the inlet box?

 

[Hullguy]

After reading a bunch more, I am thinking more and more that the unconnected neutral is fine and the interlock is really the way to go.

If I owned my home, I'd certainly do it myself. But, I rent my house. So, to get permission from the owner, I have to use an electrician. I am hoping they agree!

Again, not advice ?

This electrician wouldn’t agree!

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