I have a 120/240 V 3 wire overhead service with the following. Voltage measured at POCO mast connection L1-L2 230V L1-Neutral 114V L2-Neutral 116V.Inside the house I have in the panel at the main lugs L1-L2 220V L1- Neutral 100V L-2 -Neutral 118/120V. I am unable to pull the meter to check voltage there due to a POCO lock that has been installed for whatever reason. Can a faulty meter be causing this type of abnormal reading? Owner tells me that several light bulbs burned out all at the same time and that lights dim considerably when she starts the electric dryer. I was to this house about a week ago and added a dedicated laundry circuit, I did not check the voltage I simply verified the install with a 3 eye GFCI tester. Seems as if it were a neutral problem it would show up when metering the hot legs in the panel. Any thoughts?
Voltage??
- Thread starter nizak
- Start date
- Status
- Location
- New Jersey
- Occupation
- Journeyman Electrician
Almost certainly a neutral problem. Could be in the meter enclosure or at the service point where the SEC's connect to the POCO conductors or even further up the line.
- Location
- Placerville, CA, USA
- Occupation
- Retired PV System Designer
If it is a high resistance neutral problem somewhere between the mast and the panel, this is exactly what you would see. The imbalance between L1 and L2 to neutral should go away if you open all of the load breakers in that case.
hillbilly1
Senior Member
- Location
- North Georgia mountains
- Occupation
- Owner/electrical contractor
Probably a loose connection or burnt lug in the meterbase from the sounds of it.
hillbilly1
Senior Member
- Location
- North Georgia mountains
- Occupation
- Owner/electrical contractor
I don't think it's a neutral problem with those voltages, L1 to L2 voltage is lower than at the mast, probably bad connection on the L1 side. Loose neutral will not affect the voltage between L1 and L2.
bobbymari
Senior Member
- Location
- los angeles ca
If bulbs are blowing usually thats a nuetral problem indication but alot of times youd be getting one low reading on one phase and an abnormally high reading on the other. How bout out of main breaker outside where the meter is did you check voltage comming out before it comes into your inside main lug panel? Definetly sounds like issue is going to be somewhere in that meter panel, could be burning on the buss, loose neutral in the outdoor panel, burned buss screw , I've seen a bunch of different things. Think you need to get poco out there to unlock meter so you can get in there and check it out. Again definetly sounds as if problem is between point of attachment and your interior panel, and yesI've also seen faulty meters not putting out correct voltage
- Location
- Placerville, CA, USA
- Occupation
- Retired PV System Designer
duplicate: please delete.
Last edited:
- Location
- Placerville, CA, USA
- Occupation
- Retired PV System Designer
You mean 114 plus 116 is not 220?
OOPS!
But maybe a bad neutral in addition, or else the burned out light bulbs were just a coincidence.
hillbilly1
Senior Member
- Location
- North Georgia mountains
- Occupation
- Owner/electrical contractor
You mean 114 plus 116 is not 220?
OOPS!
No oops, the OP specifically states at the mast he is getting 230 beteen L1 and L2, inside he is getting 220 between L1 and L2, thats a lot of voltage drop on a run that is probably not 20-30 at the most. So unless his measurements are wrong at the mast, and with L1 at 100 volts to neutral inside, L2 would be much higher than the 118/120 he states if it is a neutral problem.
bobbymari
Senior Member
- Location
- los angeles ca
agreed! but bulbs blowing out is whats throwing me off as thats normally sign numero uno of neutral issue could be a power issue with an intermitant loose neutral issue as well, gotta get in that meter panel
I am going to get the POCO involved in the morning. Even if the meter was not locked I would be apprehensive about pulling the meter out of the socket. The socket looks to be an original 60A that is in rough condition. Years ago I made the mistake of pulling a meter out hot and the fixed jaws in the socket had deteriorated(aluminum or pot metal) and they came out as well. I'm very fortunate I did not have a ball of fire in my face. I am already convinced that regardless of what I find in the can it will end up being a new service upgrade. The panel is a Pushmatic split bus and it's at least 50+ years old in a damp basement.
hillbilly1
Senior Member
- Location
- North Georgia mountains
- Occupation
- Owner/electrical contractor
Good call, I have so many guys that complain that we will not let them install plug in breakers on a live buss, Not even withstanding 70E, I've seen overheated buss insulators that are ready to crumble, and all it takes is the pressure from snapping a breaker in to finish it off. I had one tech call back after I denied him a permit to replace a bad snap in breaker, and made him shut it down. When he removed the old breaker, the buss insulator fell apart when he pulled the old breaker out. He was glad I turned him down.
bobbymari
Senior Member
- Location
- los angeles ca
ahhh the old pushmatic bulldogs. Shouldn't be hard to get a service upgrade outta that one. Good luck bro and be safe!!!!
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