Neutral absent

[Bryanmarsden]

I am running a sub panel from an existing 400A panel RT. RT is being fed from an 800AMain panel in a separate building in a multi building retirement home. The engineer is calling for a 125A 3 pole breaker to feed the new panel LP in a remote building. This will take the place of the existing panel in a laundry room, this remote building currently has its own separate service, by eliminating this it will allow generator control over the LP panel. The problem is that the RT panel does not have a neutral just 3 phases and a ground. There is a 400a disconnect and a different 200a panel in the same room as the RT panel that contain neutrals, is there any code which would or would not allow me to use a neutral lug from one of these other devices (the disconnect is fed from the 800a main and is feeding multiple things one of them being the 200a panel) other than the panel RT in which the breaker would be feeding from?

 

[LarryFine]

1. Welcome to the forum.

2. Not sure of the code, but no, you can not grab a neutral from another feeder. All conductors of a given feeder or circuit must be grouped within one conduit or cable.

3. You should look into:

a. Taking the entire feeder from the source that has the neutral.
b. See if you can add a neutral and a neutral bus to the existing one.
c. Use a transformer to derive a neutral from the feeder that does not have one.

 

[infinity]

As Larry stated you need to run a feeder with it's own neutral in it. If the separate building already has a service of it's own you probably cannot run another feeder to anyway so you might need to redesign the entire thing.

Welcome to the Forum.