Voltage Problem - Lighting Circuit

I've also seen this problem caused by loose neutral neutral connections at the transformers, meter sockets & in panels. Ultimately all neutral wires [& grounds] need to end up connected to the center tap in the secondary of the power company's transformer. Loose connections between the panel neutral bus & the tranny center tap cause the panel neutral potential to "float" instead of being about zero volts with respect to ground & about 120 volts with respect to either [240 volt] hot terminal. That wasn't your problem but if lights dim or brighten a lot when 120-volt motors or heaters start check voltage between neutral bus & power line in terminals on either side of your main breaker with these devices are on. I've seen several main breakers develop resistance with age [mainly 100A breakers]. [A weird & rare occurrence that can happen is that a neutral connection opens up in a building & the neutral unbalance fault current flows between ground ground rods &/or cold water pipe bonding to those in neighboring buildings, particularly if they're fed by the same tranny.]
 
Wireaddict said:
I've also seen this problem caused by loose neutral neutral connections at the transformers, meter sockets & in panels. Ultimately all neutral wires [& grounds] need to end up connected to the center tap in the secondary of the power company's transformer. Loose connections between the panel neutral bus & the tranny center tap cause the panel neutral potential to "float" instead of being about zero volts with respect to ground & about 120 volts with respect to either [240 volt] hot terminal. That wasn't your problem but if lights dim or brighten a lot when 120-volt motors or heaters start check voltage between neutral bus & power line in terminals on either side of your main breaker with these devices are on. I've seen several main breakers develop resistance with age [mainly 100A breakers]. [A weird & rare occurrence that can happen is that a neutral connection opens up in a building & the neutral unbalance fault current flows between ground ground rods &/or cold water pipe bonding to those in neighboring buildings, particularly if they're fed by the same tranny.]
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I learned about the open neutral situation personally about 30 years ago when the buried utility opened and did weird excursions in all of the lamps. The repair guy arrived on the scene in less than a half of an hour. When I remarked on how quickly he showed up he responded "We don't want to burn your house down" !!
 
i have to check ground often..when you pop a breaker while welding the amprage has a tendency of straying down the line
 
It is a good practice to tighten the terminal screws ground, neutral and hot, in your breaker box annually. They can become loose over time due to heat expansion and contraction. All wiring vibrates slightly at 60 Hz which can cause bad connections to loosen and insulation to wear through if it touches a sharp edge.

Good connections are very important. I like Ideal "B-cap" wire nuts because you can unscrew them easily. All wire nuts must be the right size and have a metal spring inside. 3M makes some multi-colored wire nuts that have an expanded range that can be very convenient. Remove 3/4 inch of insulation, twist the wires together with lineman's pliers, trim to 1/2 inch, secure with wire nut. Best practice is to tape wire nut to wire, and tape all plugs and switches.

If you have a Federal Pacific breaker box, replace the entire panel ASAP. They to not work, and do not provide circuit protection. Square D, Siemens, GE and Cutler Hammer are the major reputable manufactures of electrical panels. If you have a different brand, do some research or have an electrician check it out.
 
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