Question on connecting bus 120 v panel to inlet

Corbi

Senior Member
Joined
Mar 6, 2021
Posts
166
Location
New England
I am curious what grade wires you are using to connect your 120 v inlet to your service or 120 v power panel. The directions on the panel say to use 8 gauge wiring, so I bought some for this purpose. What about connecting up the ground/3rd wire? Can that be a more common gauge like 12 or 14? The panel bus bar seems to have smaller screws for the ground wires. I realize that the 12 gauge Romex wiring I’ve purchased for the bus interior has a plain copper wire. I would like to have an insulated wire when I’m connecting the inlet ground to the service panel ground (not neutral) bus bar. I’m thinking that unlike a 9 volt circuit, the 3rd wire is for an accidental break in the neutral wire, so an insulated 3rd wire would work in that case instead of an uninsulated single strand of copper wire. Any thoughts or advice out there?
 
Fire Safe RV w/ Smokey Bear.

Please post picture(s) of the panel so we can see the panel style & termination points.

#8 is good.... blk, wht, grn (& red)? What wiretype are you using to feed the panel? SO cord, romex, conduit w/ thhn.....?

Ground & Grounded Conductor bus terminals ought to accept up to #8. Cut straight, back that screw out, eeaase it on it there.

Also, the Ground is so much more than OP described. Especially with gfci pedistals, diy inverters, rubber tires, metal bus, bare feet(pets/kids) ungrounded neutrals, arc-fault, arc-weld, lightning/surge protection, white fire....

The least resistant path to planet Earth, really is important to 120v RV systems.
 
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Additional info on my 120v connection

I posted a picture of my 120 V panel and the 8 gauge wire I purchased.

I added the ground bus lower right, and the large connectors leading to my inlet fixed to the outside. About colors, since my box and inlet are close together, my plan was to use white paint or marker to id the neutral wire, and another gauge wire of a different color for ground. I also need to ground the panel to the bus frame, correct? (Not neutral). Thank you for your interest and council. I'd rather not become toast!
 

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Can of worms, am I right?

The wire is fine. White marking tape on the neutral, prefered. The ground wire can be derated, #10 green or bare solid copper (better).

That wire type "shall be" pulled into conduit (pvc, emt, rigid) only after the conduit body is completely installed (boxes, pipe, straps, connectors, bushings...).
*Where does the other end of the raceway terminate? An approved box, right. Bell box, pvc... then maybe change over to an SO cord?

The panel looks like a combo, 120v either/or 240v, depending on line (2 hots or 1) supplied and whether or not a jumper is installed connecting the buses.

Three breaker positions on each bus as split phase 240 or six on one if jumped to a single 120v line.

Upload a picture of the label in the bottom of the panel and I'll tell you for sure. It's just my interpretation of the photo.

The ground bar is installed with one screw through the center. Which is ok. What type of screw? Not self tapper, right. Must be mechanically secured. ie drilled & tapped with machine screw (8-32) or nut on the back of bolt. Tight.
 
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I posted a picture of my 120 V panel and the 8 gauge wire I purchased.

<snip>

I also need to ground the panel to the bus frame, correct? (Not neutral). Thank you for your interest and council. I'd rather not become toast!

That is best practice, to ensure any short along one of the branch circuits has a more direct route than your body back to the panel's ground, and ultimately the shore power ground, improving chances that a circuit breaker will trip safely.

What is the brand of that subpanel?
 
More on my panel

Thank you for looking into this; as everyone knows, I'm learning as I go along. The brand of the Panel is Square D. I attached pic of label.

I have some 1/2 in pvc pipe with right angle connectors that I can use to enclose my 3 wires from the inlet to my panel as they leave the inside and connect to the area behind the body where the box will be attached.

Inside, I will attach 12 guage romex from the 15 amp fuse to a standard 3 prong outlet in a metal box.

I was planning to run the wire along the seat attachment bar to the outlet. Only a few feet. I'm wiring for a small fridge.
 

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It all sounds reasonable. Be sure to set each screw lug, then loosen, then reset for all wires. The copper wire will need two tries to seat properly in some cases.

Do a wiggle test of each conductor after the above. Solid conductors are a pain to bend into the right shape as they go into the circuit breaker or bar.

I used 8/3 Romex for my 30A shore power connection. It loops about three feet to a subpanel without conduit. It's in it's own little protected area, so I figured conduit didn't make sense.

For branch circuits I ran the Romex (yes, I used Romex) in plastic surface mount wiremold raceways instead of stuffing them into the chair rail bar. I did a neat job of it and it's relatively easy to inspect.

Speaking of inspection, I recommend you put together a preventive maintenance log and add wire inspections to it, maybe once a year.
 
Moving along

I'm glad to have reached out. I saw on the Ace Hardware a piece flexible tubing with a panel attachment. If I can find one, I'll feel better than having a right angle pcv joint from the inside to the outside connection. It's not easy to match the holes in each box to where the wire is going through. Its taken some sawing and rethinking. Now, if I can just finish the install, I'm ready to take Corbi on the road!
Thanks, Gerard
 
3/4" lfnc

Look for Liquid Tight Flexible Non-Metallic Conduit - LFNC, (brands: Sealtight, Sealproof) remember to pick up two connectors (maybe one 90°?) and a few rigid straps. I'd upsize to 3/4", if you can. Easier to pull through &/or upgrade. (Three #8 is max fill for 1/2" conduit).
 
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