One Generator, Two Outlets, Two Main Panels

[mlange]

Have 400 amp service w/ two main panels, interlocks and a 50 amp backfeed breaker on each, and a 50 amp inlet for each.

I've got a Champion inverter that I've changed to a floating neutral already. It has a 50 amp and a 30 amp outlet on it - both 240v.

Can I run the 50 amp outlet to one of my inlets and the 30 amp outlet (w/ an adapter) to the other one of my inlets? Or will that in effect be bonding the neutrals across the two panels?

 

[mm08822]

The problem is when both cords are connected, the neutral current will split between both cords' neutrals until approximately equal.
This path occurs due to the connection from each panel back to meter pan. This could be a hazard if anyone is working in meter pan.
Also if one of the cords is not connected at the generator end, the exposed neutral blade is a shock hazard.
I have to check the code for this situation specifically as I never ran across this configuration need.

 

[wyliesdiesels]

You mentioned the receptacles are 240v. They should actually be 120/240 4-wire.

 

[mike93lx]

Maybe have the generator feed into panel #1 and then tie panel #2's interlock into a breaker in panel 1. You'll have one inlet that can light up both panels and they'll both have interlocks.

 

[mm08822]

Maybe have the generator feed into panel #1 and then tie panel #2's interlock into a breaker in panel 1. You'll have one inlet that can light up both panels and they'll both have interlocks.

But the parallel path is still present made by each panel's neutral block and conductor through the meter neutral connection.

 

[micromind]

The interlocks are a form of transfer switch. Any number of generators can feed any number of transfer switches.

On of the casinos I used to do electrical work in had 2 separate PUCO services, 4 gens and 17 transfer switches. All code compliant.

 

[mm08822]

2 separate services is different than the OP's 2 panels on a single service.

Transfer switches can include a pole for switching the neutral, so not necessarily the same as an interlock.

 

[Innovate1]

Maybe have the generator feed into panel #1 and then tie panel #2's interlock into a breaker in panel 1. You'll have one inlet that can light up both panels and they'll both have interlocks.

This seems like the best solution. I have two main 200A panels and have the interlock on one panel. If I end up needing to power things on the other panel I would probably go this route as it then allows me to power anything on either panel. I only have a 30A feed and an even smaller generator so will have to seriously limit how much is on at once but could power any of the smaller circuits this way. This doesn't create an alternate neutral path - the interlocked feed between panels is only the two hot lines. The ground and neutral are already connected between panels.

 

[mm08822]

Maybe have the generator feed into panel #1 and then tie panel #2's interlock into a breaker in panel 1. You'll have one inlet that can light up both panels and they'll both have interlocks.

This seems like the best solution. I have two main 200A panels and have the interlock on one panel. If I end up needing to power things on the other panel I would probably go this route as it then allows me to power anything on either panel. I only have a 30A feed and an even smaller generator so will have to seriously limit how much is on at once but could power any of the smaller circuits this way. This doesn't create an alternate neutral path - the interlocked feed between panels is only the two hot lines. The ground and neutral are already connected between panels.

All conductors of the circuit need to be within the same conduit or cable. If your plan is to only connect the 2 hot leads from the tie cb in panel 1 to the tie cb in panel 2 and rely on the existing neutral connections that connect through the meter pan then this is just another code violation. Sure it gets rid of the parallel path but still not kosher.

Put the critical loads in one panel.

 

[mike93lx]

Put the critical loads in one panel

That is what I did in my two-panel setup. Moving a couple circuits was a lot easier and cheaper than tying them together

 

[Innovate1]

All conductors of the circuit need to be within the same conduit or cable. If your plan is to only connect the 2 hot leads from the tie cb in panel 1 to the tie cb in panel 2 and rely on the existing neutral connections that connect through the meter pan then this is just another code violation. Sure it gets rid of the parallel path but still not kosher.

Put the critical loads in one panel.

Perhaps you are correct technically but the neutral and ground lines just go to the meter base on the other side of the wall in my case. And the conductors are sized for 200A services and will have at most 30A when on generator power. Practically speaking it will be fine. Not that I am thinking I will probably ever have the need to do it.

 

[theoldwizard1]

The interlocks are a form of transfer switch. Any number of generators can feed any number of transfer switches.

Interlocks, at least for residential panels, only switch the hots. The neutrals and grounds are straight pass-thru. This is the OPs concern.

 

[wyliesdiesels]

Interlocks, at least for residential panels, only switch the hots. The neutrals and grounds are straight pass-thru. This is the OPs concern.

interlocks actually dont switch anything at all. interlocks are a piece of metal.

 

[wyliesdiesels]

The interlocks are a form of transfer switch. Any number of generators can feed any number of transfer switches.

On of the casinos I used to do electrical work in had 2 separate PUCO services, 4 gens and 17 transfer switches. All code compliant.

not even close. interlocks are a piece of metal. a transfer switch is a double pole double throw switch(in the case of 120/240 service rated TS).

the breakers used with interlocks do not meet that characteristic

 

[micromind]

not even close. interlocks are a piece of metal. a transfer switch is a double pole double throw switch(in the case of 120/240 service rated TS).

the breakers used with interlocks do not meet that characteristic

The code defines a transfer switch as "An automatic or nonautomatic device for transferring one or more load conductor connections from one power source to another".

Certainly, the interlock itself is not a transfer switch but when combined with two breakers it seems to fit the definition.

 

[theoldwizard1]

Certainly, the interlock itself is not a transfer switch but when combined with two breakers it seems to fit the definition.

Poorly stated by myself ! Thank you !