Voltage drop - panel or utility issue?

[Dave Garrett]

My electrical knowledge is fairly limited, so I'm hoping someone here can shed some light on this or correct any mistaken assumptions on my part. Our house is 60+ years old, previous owner worked for a homebuilder and did a lot of the improvements to the house himself. We've been here almost 7 years, and have had relatively few problems outside of the usual age-related ones.

The room being used for an office has two computers, two monitors, flatbed scanner, inkjet printer, router, cable modem, external drive, two powered subwoofers, and a small desk lamp. The computers each have their own UPS (APC Back-UPS ES 650 and 500). Within the past few days, the UPSes have started clicking several times a day. These UPSes beep several times when switching over to battery power, and they haven't done that more than once or twice, but the clicking would seem to indicate a voltage drop significant enough to cause them to start to switch over. This only lasts about a second or less, and I've observed the lights in the room flickering just a bit at the same time. I've also observed lights flickering slightly in other rooms, so it's not limited to just the office.

So, I decided I'd better get someone out here to look at the panel. I have a main panel (125A) and a subpanel (75A), and they are both of the notorious FPE Stab-Lok kind, the evils of which I just learned about after doing a bit of Googling. The guy that I hired examined both panels and tightened down all the connections, and said everything looked OK as far as he could tell, but recommended that when I'm ready to upgrade I should install a newer panel with more capacity (the breaker on the subpanel that covers the office also covers two halogen wall-mounted lights in the hallway, the master bedroom, the guest bedroom, and the living room. The guest bedroom and the living room are very infrequently used.). He also reanchored the utility drop where it splits into three main cables just upstream of the meter (hope I'm using the correct terminology here), as the cables had come loose from the "anchor" mounted on the house and were "pulling" on the connectors.

I thought this must've fixed the problem, as it was not reproducible while he was here, but a couple hours after he left, the UPSes started clicking again. I'm concerned that this will ultimately cause damage to the computers or the UPSes, and am wondering whether I need to get a second opinion from another electrician, or whether I should call the utility and ask them to put a line monitor just upstream of the meter to see if it's an issue with their equipment. I'm concerned about the panels after reading about FPE's failure rates, but unless I get a professional opinion that they're unsafe and should be replaced immediately, I'd prefer to defer doing so until a couple of other expensive improvement projects are completed.

Comments or recommendations?

Thanks in advance,

Dave

[Edwin Pawlowski]

Since you have more than one UPS doing the same thing, I'd have to say they are doing their job.

Why not start with something simple. Buy or borrow a volt meter. Something accurate enough to see a drop of say, 4 or 5 volts. Plug it into any place in the house. Actually, try a few places and they should all read the same. When you hear the UPS engaging, take a voltage reading. Do it a few times during the day and if you find variations, record them. You may find a pattern. If you see drops, call the power company. There can be a differential of a couple of volts during the day as major industry comes on line or shuts down, hot weather cranks up the AC, etc. Too much = problems

When I had a problem with bulbs burning out, I did some checking and found morning spikes to 145 volts. There was a problem at a substation transformer and quickly corrected. You'd think the utility company would have a better handle on stuff like that, but not always.

[John Grabowski]

You mentioned two things that always send up a red flag for me; The previous owner did a lot of improvements himself and you have a Federal panel. The electrician was right in checking and tightening all of the connections in both panels, but you could have one or more bad circuit breakers that are causing the lights to flicker.

You could also have loose connections in one or more outlets, switches, and junction boxes on the problem circuits. It could also be a problem with the electric service coming to the house. The fact that the overhead conductors were pulling on the connections is an indication that the problem may be right there. I would call the power company and have them check the service drop from the pole to the house. The connections inside of the meter should also be tightened. In the mean time keep a record of time and date when you have these occurrences. It may be useful in correlating your problem with something else. Are your neighbors having the same problem?

Regarding the FPE panels. I suggest that you get estimates from several contractors on the cost to replace them.

John Grabowski

[Pete C.]

Certainly old crap panels should be replaced at your earliest convenience. When you take your voltage readings take them at several different locations i.e. near the beeping UPS and somewhere close to the main panel. This will help isolate whether it is a house problem or a utility problem.

I had an interesting utility issue once. I walked by my server rack and noticed the UPS was on battery and beeping. Since the power was obviously not out I checked and the UPS reported input voltage of 135V and had switched to battery on it's over voltage protection. I got my Fluke DMM and verified 134.8V at a nearby outlet.

I called the utility and while the CSR I talked to had no idea what I was talking about, she took the info and within 10 min I got a call back from a tech. I told him what I had found and in less than 10 min he was parked in my driveway. Before I even got out to the truck to talk to him he had confirmed the high voltage and was on the radio to another tech heading to the regulator back a few miles away. A few more minutes and I had a reasonable 126V. I was pretty impressed with the utilities response time.

Pete C.

[Tony Hwang]

Hi, FPE panel is bad news! And didn't the guy use amprobe and volt meter when he worked? Even 'scope would be useful. Excess voltage drop can happen from loose connection, under rated wiring(over loaded circuit) or bad ckrcuit breaker, improperly balanced 110V leg on the panel, etc. Noticed any breaker getting warm to touch? If you can hang a real time power monitor, you'll see everything; sag, spike, frequency drop, etc.

[hallerb]

how old are the UPS units, after a few years 2 or 3 the batteries go bad and the units act wierd.Espically bad on small UPS units like those

40 buck units

I have a couple doing that here.

DEFINETELY GET RID OF the FPE panels its a fire waiting to happen!

Put a voltmeter on the line, sometimes minor fluctuatins appear large to certain lamps. I had some cheap fluroscent shop lights that acted wierd with a 2 volt drop, a trivial change.

[FDR]

I've heard bad things regarding FPE as fire hazzards.

[Pat]

It could be your problem or it could be the utility's problem. Since you have checked for problems I would try the utility company next.

[Dave Garrett]

Many thanks to everyone who replied with suggestions. A few additional comments:

I'm not sure the previous owner did any electrical improvements himself

- he may well have contracted that kind of work out, especially since he was in a position to have plenty of contacts who would be capable of doing such work.

The guy that examined everything last week commented that whoever had installed the panels had done a pretty good job (not that in this instance that has any bearing on how well they function, obviously). He did check all the panel connections with a meter after tightening them down, and didn't see any readings out of the ordinary.

None of the breakers are warm to the touch even slightly. Some of them have tripped as they were supposed to in the past, but this has not been a frequent occurrence.

I don't have a voltmeter, but I can certainly borrow one from my dad, and this will probably be my next step. I'm definitely going to call in a ticket to the utility as well and have them check the service drop and meter. Not sure if my neighbors are having problems as well, but I'm going to talk to them and find out.

Finally, I'm definitely going to have the panels replaced, it's just a question of when funds become available to do so. Glad I found out about their history now rather than before they became a more serious problem.

Dave

[Tony Hwang]

Hi, One thing batteries inside UPS don't last forever.

[twstanley]

We have the same thing happen time to time. As the electrician has checked the internals and not found anything, I think you are on the right track contacting the utility and having them check their side of the hookup.

You might also note the times, is happening about the same time every day?

Also ask your utility rep if they are having voltage drops or spikes occasionally, they may be able to advise you or may need to know about any voltage changes you are seeing.

Hooking up the voltmeter and watching it while the ups's are beeping and clicking is a good idea.

[Dave Garrett]

Well, I reported the problem to the utility today. We'll see how long it takes them to check it out - the CSR I talked to at the service provider before I was referred to a different number used to report power outages said it might take several days before they show up after I described the problem to him.

It's not happening at the same times, but I did notice today that it does seem to occur frequently when one of the major appliances like the refrigerator or dishwasher kicks in. I also noticed it was happening almost every time the A/C turned on (it's just gotten hot enough here for it to be in use again).

And to answer a previous question, the UPSes are both relatively new - less than a year old - so the batteries in them should be fine. The battery dying in my old UPS was what prompted me to replace it with these.

Dave