Off-Grid Shed

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Old 10-07-20, 06:26 AM
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Off-Grid Shed

I'm wiring an off-grid shed that will never have main power supply, so no concerns of transfer switches or feeding back to the grid. I have a Reliance outdoor rated PR30 power inlet with an L14-30 connector and a Square D QO112M100PC service panel with plug on neutral. I have a 30A generator.

Questions:
1. The PR30 has four wires. I don't know if I'm to connect the white neutral to the ground in the PR30 box or pass it through to the service panel. I actually don't think it matters given my service panel.
2. The service panel has what appears to be two neutral bars and one ground bar which appear to be physically connected. From what I can read, given the generator supplies power to this as the main panel, I am to use the bonding screw. My confusion stems from the appearance that the two neutral bars look linked to the grounding bar, making it somewhat confusing as to which is the neutral bar and which is the ground bar. In fact, the minimal instructions show two build in neutrals ("N"), with a picture showing a ground can be attached to one of the neutrals "where required". So, the instructions are not quite clear as to whether it matters which is truly the ground versus the neutral bar. Now, with OCD, I only imagine the grounds should be on one bar and neutrals on another bar, but electrically it doesn't seem to matter.
3. I am planning on a short run of 10/2 Romex with ground to connect the PR30 and the QO112M100PC given only 30A supply. Jump out to anyone as too small?

Thanks
 
  #2  
Old 10-07-20, 08:39 AM
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Hi, you will need a10/3 cable, the neutrals are connected together and come down either side of the panel, 4 wires from the receptacle into the panel.

Geo🇺🇸
 

Last edited by XSleeper; 10-07-20 at 11:40 AM.
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Old 10-08-20, 05:15 AM
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Thank you Geous.

The panel has four neutral bars (A, B, C, D). The instructions say C can be used as the ground. If I use C as the ground, then the neutral and ground will be connected, even if I don't use the bonding screw. As such, I am confused by trying to keep the ground and neutral separated or not. There are the two incoming hot H connections and the incoming neutral to B. Circuit breaker neutrals to A and D.

In my off-grid project:
1. Bond screw or no? I assume yes.
2. Bar C as ground or separate bar attached elsewhere in panel? I assume to use C and follow diagram.


 
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Old 10-08-20, 06:54 AM
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You are doing a service entrance using a genset correct? So, this is a service panel, not a subpanel. I don't see a ground bus in that panel, only 4 neutral busses. But, in your case, N, the box screw, and all circuit grounds are to be in common.
 
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Old 10-08-20, 02:10 PM
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If the generator has a bonded neutral then the service panel neutral needs to be unbonded and a ground bar needs to be added. If the generator has an isolated neutral then the panel neutral is bonded and a separate ground bar is not necessary. You should run an electrode ground conductor from the generator frame to two 8' ground rods driven at least 6' apart from each other.
 
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Old 10-09-20, 05:29 AM
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Thank you. I see how two grounds are recommended, but water pipes are often considered supplemental so some only use one rod. As I don't have ground water pipes off-grid, I'll need to drive another ground rod. <face-palm> Not easy in rocky land, but easy isn't always the right way.

I am using Honda EU2000i inverter generators, usually alone, but capable of parallel operation. I had run a ground rod already and was going to ground the service panel. I looked at wiring diagrams for the generators, as well as searching for other's opinions online, and it seems these generators have a floating neutral. It would seem grounding the panel with two ground rods, while connecting the ground of the generator through the generator plug to the panel, would be adequate. As I'll be bonding at the panel, I don't believe I'll need to bond at the generator with a cheater plug (https://www.amazon.com/Southwire-Com...dp/B07F4R7BDL/).

Again, thanks for your input!
 
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Old 10-09-20, 05:54 AM
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but water pipes are often considered supplemental so some only use one rod.
Actually, the water pipe is the primary ground and the rod(s) are supplemental.
 
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Old 10-09-20, 07:11 AM
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If the gen has a floating neutral then do as you said, ground rods are connected to the panel and neutral is bonded in the panel and do not use a jumper plug on the gen to bond the neutral at the gen.
 
 

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