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generator distribution panel

4K views 17 replies 7 participants last post by  AllanJ 
#1 ·
As I posted before I'm in a multi family house and wired up a sub panel to split the power from my generator to both boxes in the event of an outage, looking at it again today i was wondering, do I need to bond the neutral bar to the panel? The panel does nothing but distribute power and because of my interlocks could not be used as a legitimate sub panel because the only time it is energized is when the genny is running. I put a ground bar in when I installed it and the neutral bar is not bonded right now.
 
#14 ·
The neutral to ground bonding should already be in place internally in the generator. THAT is the source, and the bonding is to ensure a reliable return path to the source.

No further bonding downstream should be necessary.
 
#15 · (Edited)
Note that if the transfer switch or interlock does not switch the neutral between generator and real main panel then neutral and ground will remain bonded at the real main panel which from the point of view of the generator is a random point downstream.

Then what has been done is to use the aforementioned as the single and "real" grounding point for the neutral and to unbond the neutral from the generator frame. Meanwhile the generator frame is to be bonded to the house ground system.
 
#16 ·
From the sound of it you have the ability to back feed the service and cross your entrance with the generator.

this is how I understand it:

Service drop-(split)----panel 1-------(subpanel that splits to both panels)
-----Panel 2 ------



If this is the case it is an illegal installation.

YOU MUST have a means of MECHANICAL PHYSICAL interlock between or at/in the FIRST point of service entry to the structure and the Generator input.

You cant just flip a breaker on your mains. THEY MUST be interlocked. The generator circuit CANNOT BE ENERGIZED at ANYTIME by the service feed.

Now to answer your question, your ground and neutrals SHOULD be separate from the generator to the panel. Once inside the first panel they can be bonded together. But you run 4 wires from a 240 genset for a reason. You also should have a ground rod that is separate from the service ground rod. (Basically stating your generator should be grounded)
 
#18 · (Edited)
superfluous material deleted

Somehow I abhor having to separate neutrals and grounds in the main panel (turning it into a subpanel) as part of the process of installing a generator. Without doing that we will have neutral from the genny separate from the ground entering the genny panel, perhaps neutral is not bonded to ground there, and neutral stays bonded to ground in two other places, namely in the main panels on each side. Probably innocuous and inconspicuous given the main panels are just a few feet away. Thus I prefer to set up a generator as a separate subsystem with temporary cord and plug connections to the items I want to energize. Particularly if it serves more than one home..
 
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