I have a client that has a 1 phase 240 volt service that has a 200amp main breaker at the meter panel and two underground pull boxes to his house to a 200amp main panel with a 200amp main breaker. he also has 3 tesla power wall back up units with batteries. As of yesterday all of a sudden his lights are flickering and his Microwave is running really slow. He had PG&E come out and check there side and they said that he has a bad neutral between the main breaker and his 200amp subpanel.
I respliced his neutral wire in one of his pull boxes and he still is having a issue with his microwave. So when i put my meter on his conductors it reads 122v on 1 phase and 130v on the second phase, when he turns on his drill press that 2 phase rises to 148volt ? I have tighten up every connection between his 200amp sub panel and his tesla power wall panel and still getting the same results. I have tighten up all of his grounds and neutral connections. Is there any one out there that can help me with this situation.
Anybody check the receptacle(s) where the microwave and anything else on that circuit that has an unstable voltage?
Are those receptacle(s) fed with a multiwire branch circuit (2 phase wires,( black and red) and one neutral, white wire?
The white wire should be spliced and pig-tailed with only one white wire attached to one neutral screw terminal and not on separate terminals.
If the white wire (neutral) is not spliced and you have two white wires and one attached to each terminal it could cause a series circuit when they are separated. Resulting in higher voltages.
If you open the neutral conductor (separate the two white wires) it will cause unbalance voltages and thus be at a higher voltage.
NEC code requires that they be spliced and have one pig tail wire on the
neutral receptacle terminal.
See 210.4, 240.15 (B)(1) and 300.13(B)
Device Removal
Is there a 2 pole CB feeding those receptacle(s)?
Thanks for reading.
Comments accepted.
TX+MASTER #4544