1952 Single family. Standard 3-wire single phase service. Line A & B with neutral.
Edited: I inspected this distribution panel today and scratched my head for a while on it. Why is there a 3 phase distribution panel with single phase service? Why did the “sparkie” configure the wires this way and jump Line A and Line C? How would this affect the balance of the circuits? The #10 feeders come from a 30 amp in the service. I am writing up the two conductors under one lug but I want to make sure I’m understanding this panel and configuration before I figure out a narrative… There was a lot of substandard and hazardous DIY electrical in this home so I’m already writing hard on this report. I’m just not sure about this particular item and don’t want to incorrectly identify this wiring method.
The OCPD in the service panel for this panel was 30 amps. The wiring appeared to be #10 gauge. Wouldn’t that be acceptable and wouldn’t the means of disconnect be the 30 amp breaker in the service panel?
Jumping phase 1 to phase 3 in a three-phase panel ?
Neutrals double tapped. It can lead to loose connections, overheating, and potential electrical hazards.
This going to be out of phase?
The issue that Jim brought up has to do with the conductor range for the main and neutral lugs of the panel. Since the panel is rated for 125 amps those terminals are likely not the correct size to terminate #10 AWG conductors. Regarding the 3Ø to 1Ø conversion it could be argued that the panel listing would not allow it.
It could also confuse someone if they’re trying to run a MWBC to the panel and end up with both ungrounded circuit conductors on the same leg. That would end up not being a MWBC and the neutral could potentially be overloaded. The entire installation screams of Harry homeowner.
Your voltage readings sound correct. If you went across the three main lugs you should see A-B=248, A-C=0, B-C= 248 volts.
I’ve seen a lot of wiring like that. I’m in a very industrial area. A lot of guys get what we call a Five-finger-discount. Some factory electricians will pilfer materials from where they work and do side jobs for their buddies for a few beers and a pizza.
For many years, electrician was a bid job in auto plants. The only qualification a person needed was seniority. They didn’t have apprenticeships. It was a matter of the blind leading the blind.
All that has changed in the auto industry but I’m not so sure about small manufacturing plants. I’ve seen a fair number of new installations like that in recent years, but not anything like what I saw in the field 40-50 years ago.
As for your question about the load being balanced, that depends on how they arrange the circuits. Load balancing, however, would probably be the least of my concerns.
The real problem is that you don’t know what has been done in the places you can’t see. The panel might only be the tip of the iceberg.
Morning, George. Hope to find you well and in good spirits today.
The remote panel is a mess. You hit the nail on the head by saying, “The real problem is that you don’t know what has been done in the places you can’t see. The panel might only be the tip of the iceberg.”
Well, if the exposed part components are poorly installed, the part of the remote panel we can visibly see, there must be quite a mess downstream.
1: Besides the jumper terminating on Line 1 & Line C, leaving 2 conductors on Line 1 lug, look at the conductors AWG terminating on the OCPD’s.
2: Neutral bus terminations. Double tapping.
I left out the double tap termination on the Square D QO breaker by not marking the arrow dark yellow. You are certain that single pole Square D QO breaker can accept 2 conductor terminations? Still, no excuse for improper conductor AWG.
Point I am trying to make. Look at all the installation defects.
George Wells hit the nail on the head when he wrote; “The real problem is that you don’t know what has been done in the places you can’t see. The panel might only be the tip of the iceberg.”
Yes Square D QO circuit breakers can accept two conductors that are within the ranges written on the breaker, What are you calling out as improper AWG size? From your photo none of those sizes are incorrect for the size of the OCPD present although one of the sizes that you’ve noted is incorrect.
I realize that. Cutler-Hammer single-pole breakers from 10 to 30 amps are designed to accept two conductors in the lug terminal. Those are the only 2 brands I know.
The circuit conductor terminating at the 30 amp breaker appears to look like the same gauge as the 20 amp breaker to the left, unless it is a larger AWG than required. Then no real issues. I never took that into consideration.
I never took that into consideration.