I noticed I had an issue with no power in parts of my house. Both lights and receptacles affected. I go with my multimeter to the panel, and I have on the 8 breakers on the left and 7 on the right, in thleft side,I have power to 1,3,5 and 7. No power to 2,4,6 and 8. On th right side No power to 1,3,5,7 and power to 2,4 and 6. I see a clear pattern, but don't know what to do going any further.

  • 4
    Call your electric utility and report partial lights out. Electricity is delivered to you as two separate 120v feeds, one of them has a problem. – Tyson Oct 8 '17 at 10:54
  • 1
    Are your 240 V appliances working: a/c, electric range, electric clothes dryer? It may not be good for them to try to use them, if you have one 120 V leg out. – Jim Stewart Oct 8 '17 at 11:16
  • No the dryer is out. Luckilly it hasn't been cool enough to need the furnace. But thank you for your help. I'm gonna call PECO 1st thing tomorrow morning. – Matt Oct 8 '17 at 11:22
  • What kind of electric panel do you have: brand and type? Do you have a single master breaker for the whole panel or do you have 240-V 2-pole breakers in one section and all the 120-V breakers in a separate section? – Jim Stewart Oct 8 '17 at 11:23
  • 1
    If you have a gas kitchen range, it probably has electric igniters. Is it working? What about the refrigerator? What kind of water heater do you have? Most tankless gas water heaters now require 120 V for controls. – Jim Stewart Oct 8 '17 at 11:31

It is clear that you have lost a phase or a neutral. The reason you are getting strange readings is when you experience a phase or neutral loss it can turn some circuits into series circuits. This causes all kinds of weird things and readings to happen.

Start by turning all of the branch circuit and feeder breakers off. Then check the voltages just below the main breaker. You should read approximately 120V to the ground bar on both phase A & B, and 240V across A & B. If you are reading anything other than that. You have lost a phase. Then you can do the same thing to the incoming lugs above the main breaker. If you get different results than what you just read below the main, then you have a bad Main breaker. If you get the same result your problem is either the utility power or at the meter.

If you get the same results above and below the Main, then disconnect the ground wire from the neutral bus and take the same readings both to the neutral and to the ground. If you are getting voltage to the ground and not to the neutral then you have lost a the neutral, and it is usually between the panel and the utility power. Do you have an overhead drop? I have frequently found a break in the drop neutral (the bare wire).

Use extreme caution when taking these readings because you have no real overcurrent protection if you foul up. If you feel uncomfortable then you should bring in professional help.

The bad news is that if it is a main or the meter installation, you will need a professional to do the repair. I would never recommend that a DIYselfer try to make the repair, since it requires a trained person in safety and procedure to perform such a replacement.

The good news is if it's a break in the utility drop. Then they will make the repair.

Stay safe and good luck.

  • Some utilities (the one in my area at least) will pull the main panel cover and tighten main breaker lugs while they are out on a ‘check customers service’ type of call. They stop at that point tho, if a main breaker needs to be replaced they will not, in fact they will pull the meter and red tag the meter can. Customer would need an electrician and emergency city permit at that point. – Tyson Oct 8 '17 at 21:51

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

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