I swapped out an electrical panel with a screw in type breaker to a switch breaker. I switched off power at the service box and began the conversion to this Siemens PL Series Load Center

This conversion was done because the owner of the trailer, a good friend's dad, had no power to much of his home. The top breaker, which is not attached in the picture, was taken off after getting no power through to the right or left leg plates (tested with a meter) after turning on the service breaker (2 x 50amp). The black hot leg was not hot from the service but the red had 121v from the service and was hot. I checked the inside panel's main breaker with an ohm tester setting on my electrical meter and when both leads were touching the terminal and I got a reading of 0.1 for both individual terminal posts. However, when I touched the leads to the post and the corresponding plate, I got 1. I believe the problem is with the breaker in the box as well as the breaker at the service. What do you think? Does the electrical look right? I do know that the individual breakers are not the correct amperes that will be needed. I am working with what I was supplied. The electrician that worked on it last had everything on either 15 or 20 amp screw in breakers and left 2 of the spaces for the screw in breakers damaged. It was a mess.

  • This is a photo of the “before” mess, right? Nov 27, 2021 at 0:31
  • No this is the after picture sans the main breaker Nov 27, 2021 at 1:11
  • I am struggling to see how the Service Entrance wires are hooked up. Nov 27, 2021 at 3:00
  • 1
    "This conversion was done because the owner of the trailer, a good friend's dad, had no power to much of his home." - additionally, it is illegal for non-licensed electricians to do electrical work on residences you are not the owner of. If you are going to ignore that restriction, you should at least have the good sense to read up on what you need to be doing before starting the job, rather than halfway through. Nov 27, 2021 at 3:01
  • 1
    I see what appears to be the neutral and ground bus bars reversed, and a jumper between them right across available breaker slots, not a good look. Nov 27, 2021 at 3:04

1 Answer 1


First, you have to fix all this faulty work - or call a pro

It isn't actually legal for you to work on someone else's house. It creates severe liability for you - if anything goes wrong it's all on you. Just between you, me and the woodpost, you can get away with if the work is tip top -- however this work is the exact opposite. It needs to be fixed properly, for your liability reasons alone! Also so you don't kill your friend.

And I don't think I'm telling you anything you don't already know, but it sounds like the urgency of "get-er-done" got in the way of proper work, also perhaps a lack of supplies on-hand such as cable clamps.

They will chase you out of the house once the power is restored, so use that to fix this panel NOW. Then work on the power problems. Also Harper's Rule: if multiple things are broken, fix all the broken stuff because you never know! Let's work the list of things I see.

  • All large lugs must be torqued to spec with a torque wrench. This is important! Torque wrenches intended for 1/4" sockets will have the correct working range. Code actually requires ALL lugs be torqued to spec. Small also. But it's most important for large lugs e.g. main breaker to bus.

  • Neutrals need to be on the neutral bar ONLY. These are the inner bars insulated by the plastic. You can't swap bars like that! If the wires won't reach, either a) extend with wire nuts, or b) mount the panel inverted so main breaker is on the bottom. Both are legit.

  • This is a subpanel. Grounds must be on the ground bar not neutral. Ground bars attach direct to the metal case.

  • The neutral-ground bonding pin must be removed.

  • I do not know what's up with that (apparently factory?) neutral crossover wire, but it needs to go back where it belongs.

  • Feeder must be 4-wire. Copper feeder is not better and is a waste of money. For 50A, #6 AL feeder is fine, and that stuff is dirt cheap. Every lug in the panel is made for aluminum wire (notice the bars are made of aluminum). I would just use #2Al because that makes the house 100A-ready, unless the lugs at the far end can't take #2.

  • Someone drilled a hole in the panel to mount a ground wire. That's all fine except they did it ON A KNOCKOUT. Not allowed there, have to do it, well, anywhere but on a knockout.

  • Can't just bring a cable through a hole! You must put a cable clamp in the knockout and bring the cables through it (according to its rating, they make clamps for 2+ cables). They also make "oops clamps" that can be retrofitted without pulling the cable out, but not for 3 cables in a 1" KO. Talk to a real electrical supply house and see what they have (they'll tell you in 1 minute, unlike Home Depot which will take an hour and give you the wrong thing). The ground wire also needs a cable clamp.

  • The feeder coming in the bottom also needs a cable clamp rated for it, another good convo to have at the electrical supply.

  • The wires come through a wallboard opening behind the panel, as can be seen at all the places that don't have cable clamps. You'll need to chisel that out a bit more so you can fit the cable clamps.

  • Below the panel, those cables aren't rated to run in open air. They need to be inside a stud wall. So I would just get some 2x4 and a bit of plywood and build a stud wall below the panel for them to pass through. Make it easily removable so it's easy to add circuits.

  • The feeder has too much sheath, forcing the wires to make a very abrupt 90 degree turn. Large wires like this have bending radius requirements.

  • All these have a very good safety reason that could kill someone. (panel chassis to neutral - yikes!!!) And by the way, a local ground rod is not a substitute for a ground wire. It needs both.

Other than that, Mrs. Lincoln, this panel sounds like a huge and very worthy upgrade. It sounds like what was there before was a huge mess, but that cannot be used as an excuse to do work halfway.

Only then, chase the lost phase

First, a panel upgrade is fantastic. Your panel is behaving like it has lost a phase.

It's rather simple: measure between the two hot phases (red and black, or black and black depending)... if you see 230-250V, you're alright. If you see 120V or 0V, you have a lost phase between that point and the utility. So check here, check at the exterior main disconnect, go as far as you can without breaking the seal off the meter.

Once you reach the meter, call the utility company. It's almost surely on their end. Report it as an outage, which it is, and they will send a truck PDQ.

Once power is restored, re-distribute the breakers so they are placed evenly on the phases, otherwise you'll have lopsided loading, excessive voltage drop and outside breaker trips. I feel like I have to say this - don't leave empty knockouts in the panel cover! You must fill them with something approved for that purpose - I myself prefer breakers because they fit better than blank covers.

  • 2
    Solid advice here.
    – Solar Mike
    Nov 27, 2021 at 21:33

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.