My compressor is on its own 240 breaker by itself. While testing all wiring to the garage we noticed that one of the feed wires to the breaker box from the meter approximately 100 ft from from each other was putting out 123 volts & the other side read 0.03 so only half the box is hot. About 5 yrs ago we switched from overhead wiring to under ground for both house & garage & are separate from each other & all has new wiring breakers & boxes. In the garage I currently have all breakers removed except 1 breaker that operates the led lights & outlet boxes, 1 breaker that is connected to a motor home, & 1 that runs the pump for our water well Which the pump is above ground. The compressor breaker is pulled because I feel the motor is fried it had power to all the wires in the back of motor but doesn't work. Now back to the well, every time the well kicks on it draws enough power to dim the lights in garage almost totally out. The pump on well is 120 volt. I'm thinking I have a bad underground main wire from the meter to the breaker box or could it be something else. The power on both each of the lead wires at the meter show 123 volts each. I appreciate any answer you can give. Thank you
Electrical – I went to turn on the air compressor which is 240v & the draw of it dimmed everything & the waterwell pulled power from everything in garage on startup
electrical
Related Solutions
All of your symptoms sound like a faulty Neutral connection. Faulty neutral causes L1 to affect L2, and has no affect on 220 equipment just like you described.
Fix that quick. A faulty neutral can damage your equipment, and because you installed a second ground, it can harm YOU as well. Check that the neutral wire is firmly connected, and using Noalox:
ALL aluminum connections for that matter should be protected from corrosion and thermal expansion with Noalox.
You are lucky that you have a conduit! You have an EASY way to remove the entire length of the neutral conductor to inspect it for damage. You should also take advantage of that conduit to pull a ground conductor through it and use that to ground your sub panel VIA your main panel. Do not use a second ground rod at the sub. It is not worth the risk in your case.
NEC 551.76.C (RV and RV parks) Grounded conductor not to be used as equipment ground. To me that says you need to isolate the ground and neutral and will need a rod at your site.
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Best Answer
This is probably a classic supply line problem. If the pump is on an opposite leg from the lighting, it's "using up" limited neutral capacity due to a poor connection Dangerous. If the pump is on the same leg as the lighting, well (no pun intended), it's taxing a bad hot connection. But I doubt that because the pump probably wouldn't even run. As Ed, 3ph and Harp have repeatedly said here, this situation sounds like an open or compromised neutral feed. Dangerous for everybody and everything. You're going to need to take measurements in various panels to make sure you have 240 across the hots and 120 to neutral and ground. Just recently it was suggested in a situation like this to first contact the power company as they will come out for free to make sure their connections are solid. Let us know what you find, we all learn from that.