electrical wiring double-check

[shooter]

this is the current configuration.  I'm stealing the wires from the AC to hook up a 120vac 30A box for my red-neck RV


the 60A exterior fuse block was installed before the siding, so I can't get full access without ripping off the siding n no way
I get authorization from the Mrs.  I can get to L1 L2 downstream of the fuses


I'm pulling the 240 60A breaker in the subpanel, will replace with a 120 30A, also changing the fuses to 30A in the pull box.
my confusion is ground n neutral.  The sub has an isolated ground from neutral where the mains has neutral and ground together. there is a ground from AC to Sub, but it's capped off, not connected.  So I have 3 wires at the new box; L1 L2 G


my thought L1 stays, L2 becomes N at the sub and I connect the capped off G to G in the sub.
looking for a consensus before i blow things up 
 

[sluckey]

Use some white tape on the L2 wire (both ends) to designate it as neutral.

[shooter]

 
couldn't find white used yellow, rang it out n taped it both ends, trip to Lowes in the AM, lightning by noon 

[PRR]

Yes, we "should" isolate N from G everywhere except the Main Panel.

That's new in the last 30 so I am rather surprised you almost have it.

You MUST have a Ground. Basic safety. Well-proven since 1912. (Before that it was debatable in theory but not in practice.)

You MUST have the White Neutral if you plan any 120V toys in your red-neck RV. The red/black pair only supports 240V. OK for fixed air conditioner or waterheater, not a US toaster or milkhouse heater or radio.

If you absolutely can not get full FOUR conductors, we did use shared G and N, and even on bare wire. Old stoves and driers were wired this way. They are real prone to stray voltage on the appliance shell, even lethal voltage, so the rules changed.

White or pale grey is THE color for neutral. Anything else will confuse those who come after you, and they will curse your legacy. Surely you have white paint? A Brother label maker with white tape?

[sluckey]

trip to Lowes in the AM

Buy a roll of white electrical tape!

A 240V 60A circuit should be wired with #6 copper. You probably have some spare #6 lugs on your neutral buss in the sub panel, but you may have difficulty connecting a #6 wire to a 120V 30A breaker. Be careful and don't muck it up.

[shooter]

That's new in the last 30 so I am rather surprised you almost have it.

I build a "Newhouse" onto the old farm house, I pestered the trades guys at work, at poker, at the BBG.
they all told me the building inspector was a %&*(^(&, so DO IT TO CODE.  so the sub I installed and wired is proper, what a PITA all the white here, all the grounds there....


the RV 120V 30A box and the trailer are both 3 wire, NOT 4.  that's where the confusion began, then when I stole the AC wires there were only 2 connected at the SUB, L1 L2.  I wired the AC AFTER I passed my finals.  There is a ground ROD at the AC and it was connected to the AC and the exterior fuse box.  I stole the ground rod to use on the lighting rods for the barn.

so I have it ready as L1 N(old L2) and the ground wire that wasn't used.  They will be connected in the SUB as L1 N G.

240V 60A circuit should be wired with #6 copper.

the 120 30A wants #10, so I trimmed a couple strands and she fits well into the recept on the box

[sluckey]

the 120 30A wants #10, so I trimmed a couple strands and she fits well into the recept on the box 

I knew you were gonna say that. I was gonna offer a simpler solution. Leave the double 60A breaker in place but move the L2 wire over to the neutral buss. MARK IT WITH WHITE TAPE! So now you have a 60A breaker protecting the #6 copper to your 60 Amp pull box, but now you only have a 120 circuit rather than 240 circuit. You should have two fuses in your pull/disconnect box but you only need one. DO NOT LEAVE A FUSE IN THE NEUTRAL LINE! You only want a single 30A fuse in the 120V line. You can use #10 to supply the 120V outlet for your RV. It's a good idea to use a wire nut to connect the #6 neutral to the #10 neutral. MARK THAT #6 WITH WHITE TAPE! This leaves a 120v #6 connected to the LINE side of your double fuse block and a #10 connected to the load side of the fuse block. No wires connected to the second fuse. Just use that for a spare fuse. I would paint 120V on the outside of that 60A fused disconnect box.

[shooter]

 


It's working, EVERY step was a disaster! when the AC compressor failed 10 years back it took out the 60A AND the 100A that feeds the subpanel, the fuses were good as new!


I bought 2 new 35A fuses, replacing the 60A's, Had 120vac on the load side of new 30A breaker, nothing at the fuses.  I did ring the wires back to the sub earlier so I could make 1 Neutral.  both rang out fine. I couldn't safely get to the line side of the box, so said screw it, bought a 120 30A fuse pull box, trimmed sealtight to get enough wire to reach the new connections, mounted the box, powered up and got proper readings at the RV plug, 116vac L1 to Neutral, 116vac L1 to ground, 400mVac N to G.

DO NOT LEAVE A FUSE IN THE NEUTRAL LINE!

the new box is a 2 fuse marked L1 and R, I installed 2 30A fuses, L1 to L1, Neutral to R. so should I just short the R fuse?

[sluckey]

the new box is a 2 fuse marked L1 and R, I installed 2 30A fuses, L1 to L1, Neutral to R. so should I just short the R fuse?

Show me the box the fused disconnect came in. Or post a link to the exact box you have.

[shooter]

It's past arthritis time n i'm pulling the AM shift at the BBG, hopefully late afternoon Sunday.

[shooter]

the box is 240, in real fine print, it was next to 2 120 single phase that I didn't like for size, or "cheapness"
I screwed up my neck n shoulder roofing, caught a bug, spent the day in bed, hopefully TUE I can "experiment".
I've verified G and N are only .48vac apart so I'm unclear why having a fuse in N is a safety problem.  gonna pull the N fuse and verify L1 and G still
provide power required and no zappies standing on earth and touching the frame.
I get the code thing, the "proper way" thing, for now I'm only interested in the won't get zapped from floating power.
i've been using a 2 wire, no G and you get a pretty good poke standing on earth and touching the exterior metal, THAT I want fixed.

[sluckey]

for now I'm only interested in the won't get zapped from floating power.

And that's why you don't put a fuse in the neutral line. Suppose the neutral fuse blows but the 120V line fuse does not blow. That will allow the 120V to still be present in the downstream outlets or appliances. You can get a very nasty shock if you touch the 120v line and earth ground. By putting the fuse ONLY in the 120V line you ensure that when the fuse blows there will be no 120v present downstream.

The only situation where it is permissible (by NEC) to fuse/break the neutral is if the breaker simultaneously breaks the 120v line also. IOW a double breaker that will trip the 120v line too if an overcurrent condition trips the neutral side of the breaker.

Bottom line is don't put a fuse in the neutral line. Wire nut the #6 neutral to the #10 neutral and don't connect anything to the second fuse lugs. And identify that #6 neutral with some white tape!

Still curious about the fuse that's marled "R". That's the whole reason I wanted to see the shipping box that your new fuse box came in. I wanted to identify the fuse box you bought, manufacturer part number.

And why did you buy a fused disconnect box? Wouldn't a breaker box be more modern?

[shooter]

That's where i got sidetracked, was looking at a "knife lever" box with breaker but it was real crappy, it failed 2 of 5 trys, the lever would hang n you'd have the jiggle to get the arm up to engage the circuit, for $40 it wasn't worth it, the next "proper" box was like the one I bought only single phase, but it was screw type fuse, I have a large pile of big fuses from days gone by, no screw types, soo.
I didn't find any 120 30A exterior  breaker boxes, other than the lever box above.


I'll mount up an isolated terminal block and jump out the N fuse, I'll pick up a lockout tag so I can warn the next person "IDiot wiring, electrician beware"