Ask the Question

mrouse · Joined: 22 Nov 2003 Posts: 2 Location: Indiana

Our house is 5 years old. I have an office that is on the same circut as our family room. This past summer, I started experiencing low voltage in my office. It only happens at night, starting arround midnight, and continues until about 6:00 a.m. It takes the form of a cyclical voltage drop. In other words, about every 15-30 seconds, the voltage will drop from 118 to less than 110, and then come back up. I have a UPS on my computer which squawks whenever the voltage drops. That means it is probably droping below 100 volts but my multi-meter is not fast enough to show it at less than 110. Since it started during the summer, and is only at night, I called the power company. They put a recorder on my meter and pronounced everything clean. I've checked other circuts in the house, and they are staying steady at about 122 volts. I have two PC's and a laser printer on the circut. If I shut the laser printer off, I can keep the voltage from dropping enough to cause the UPS to beep, but it still shows that it is dropping on my multi-meter. I have never tripped a breaker on this circut. I had an electrician friend check the wiring in my office, and he didn't find anything wrong. So if it's not the power and not the wiring, what is causing this anomoly?

AlanE · Posted: Sat Nov 22, 2003 8:08 pm Post subject:

Check for voltage drops at socket and at the fuse box.

If you have drops at socket but not fusebox I would think you have a high resistance joint in the cable. Possibly where it connects into socket or even if your sockets rely on rivited connections, as they do over here, one of them may be faulty. Try a new socket.

Drops at fusebox check live side of fuse, or circuit breaker. Drops at out side of fuse but not at in suspect high resistance connection in fuse (circuit breaker)

Drops on input to fuse would show on other circuits if all your fuses are in single box. If they are not then work back to next junction until you find drop in voltage to be free. Check that section for high resistance joint.

Sorry bit trial & error but that is only way to check. I presume you have checked the cable and plug connections to the UPS unit or carried out you meter checks at the outlet?

If I was a betting man I would put money on it being the socket outlet. Let's know if I would have won.

Alan

mrouse · Joined: 22 Nov 2003 Posts: 2 Location: Indiana

It's not a particular socket. It put the meter on all the sockets on the circut and get the same thing. The really strange thing is that it only happens at night. The voltage remains steady during the day. Midnight to six am, almost like clockwork. I tried swapping a couple of the breakers, but that didn't make any difference. Real strange.