Splice/Tap

A

Alwayslearningelec

Senior Member
Location
NJ
Occupation
Estimator
Good morning.

1. Is this a splice or tap in the trough?
2. Can this be done or is there issue with wire sizes/amperage?

1733491617968.png
 
It's a tap. The only potential problem would be making sure the #4s abide by the 240.21 tap rule.

side note: The (2) sets of 3/0 with a #3G doesn't seem correct. If they are paralleling 3/0s the #3G would be too small.
 
Last edited:
There are a few problems with this.
From FC-11 you have a 300 amp OCPD with one set of #3/0 so the wire is too small.
The tap to LP-1 has an EGC that's too small.
The parallel #3/0's are in a single raceway so it appears that they have applied derating to them but the EGC may not be the correct size.
 
infinity said:
There are a few problems with this.
From FC-11 you have a 300 amp OCPD with one set of #3/0 so the wire is too small.
The tap to LP-1 has an EGC that's too small.
The parallel #3/0's are in a single raceway so it appears that they have applied derating to them but the EGC may not be the correct size.
Click to expand...
To add, on either side of the Jbox above the trough, it denotes a single set of 3/0 in 2" conduit and 2 sets of 3/0 in 3" conduit. Not sure what is going on there.
 
Yeah there is something wrong here. My guess is that the 300 amp OCPD has only a single set of terminals so they couldn't parallel out of the FC-11. If they change the #3/0 to 350 kcmil it works.
 
infinity said:
There are a few problems with this.
From FC-11 you have a 300 amp OCPD with one set of #3/0 so the wire is too small.
The tap to LP-1 has an EGC that's too small.
The parallel #3/0's are in a single raceway so it appears that they have applied derating to them but the EGC may not be the correct size.
Click to expand...
No I think it's intended to mean 2-3" That's what 2 sets indicates.
 
Sure hope they don't need 3 phase with a neutral.

There either running single phase with a neutral or three phase no neutral.

I bet if they feed trailers they need a neutral. Yet the panel is 3 phase 4 wire.

Nice to see what the feeder schedule says.

🤔 lots of questions there.
 
Tulsa Electrician said:
Sure hope they don't need 3 phase with a neutral.

There either running single phase with a neutral or three phase no neutral.

I bet if they feed trailers they need a neutral. Yet the panel is 3 phase 4 wire.

Nice to see what the feeder schedule says.

🤔 lots of questions there.
Click to expand...
Good catch. They obviously need a neutral for the panel LP-1.
 
I would also verify the stuff regarding the #4 feeding a panelboard with no MCB. I can not see the breakers in the board but I imagine they will not meet the rules.

240.21(B) / 408.36

Do not reduce the EGC size on a tap. 250.122(G). You size the EGC based on the OCPD for ahead of the tap.


I also have never seen someone confuse pole and breaker before. kind of odd to have a 12 pole mark on the panelboard when they probably mean 12 breakers. The 7 pole on the first board would imply they are all single pole breakers? or are they 3 pole breakers and they have a 21 pole board? I think they are confused. Or I am.
 
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