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-   -   Help needed: Search found nothing. Voltage problems (http://www.diychatroom.com/f18/help-needed-search-found-nothing-voltage-problems-113871/)

karnyboy 08-13-2011 09:01 AM

Help needed: Search found nothing. Voltage problems
 
So I have this problem that has me stumped. Here is the details. My room is a small 8x16 room, I have 2 in use out of the 3 in one outlet is your standard house fan and in the other outlet is my battery back up supply connected to my computer (all dual receptacles).

Now the problem, I put my voltmeter into the wall and I read 120.4 VAC from the outlet with the computer constant, I turn on the computer and the constant drops to 119.5 VAC.

Now as I sit there I'll hear the battery back up turn on periodically at random intervals all day. Watching my meter when this happened I spiked down to 88 VAC, the battery back up turns on and for a second I am "out of power" and then the voltage spikes back up to 119.5 VAC and everything seems ok.

The lights don't flicker and I used to think this problem was exclusive to the computer, but it happens when nothing is on at all. I have my battery back up powering my alarms clock and I hear the battery back up click on throughout the day and night when I am around.

I am stumped. Please help!

AllanJ 08-13-2011 09:54 AM

Plug in an incandescent light (to the same wall receptacle, not the backup unit itself) and observe whether it flickers.

If you used an extension cord to another room (for both the battery backup unit and the incandescent light) do you have the same problem?

More Power! 08-13-2011 10:21 AM

Quote:

Originally Posted by karnyboy (Post 706210)
... I'll hear the battery back up turn on periodically at random intervals all day. Watching my meter when this happened I spiked down to 88 VAC, the battery back up turns on and for a second I am "out of power" and then the voltage spikes back up to 119.5 VAC and everything seems ok.

For starters, to clarify some terms: The drop to 88VAC is a sag. The return to 120VAC is not a "spike."

This is of course not proper behaviour. You need to isolate whether it's in the premises and, if so, where, or outside. To do that, you'll need to run more tests, from other outlets, on other branch circuits, preferably on both sides of the split phase. (I assume we're talking about typical U.S. split-phase residential service.) You'll also need to know whether there's something, or some combination of things, on the premises that, when they come on, constitute more load than that for which the service or the branches upon which they're located were designed.

Quote:

Originally Posted by karnyboy (Post 706210)
The lights don't flicker and I used to think this problem was exclusive to the computer, but it happens when nothing is on at all.

By "lights," is it safe to assume you mean something like a ceiling light in the room? Please clarify. From where are these lights powered?

Quote:

Originally Posted by karnyboy (Post 706210)
I have my battery back up powering my alarms clock ...

Just FYI: AC-powered alarm clocks often use the incoming AC, which is usually quite stable, frequency-wise, for their timing. By comparison: The output of most UPS' is wildly unstable, frequency-wise. So plugging a clock into a UPS is not generally recommended, unless the clock has its own, internal, clock source or is a so-called "atomic" clock that syncs frequently with NIST time broadcasts.

karnyboy 08-13-2011 12:53 PM

Yes by lights I mean the room lighting.

Sag yes...it is dropping, thanks for the clarification, but I think you knew what I was referring to anyway.:thumbsup:


And my alarm clock is powered by my UPS so when the power does go out in a storm I'm not late for work. lol

karnyboy 08-13-2011 12:56 PM

Quote:

Originally Posted by AllanJ (Post 706253)
Plug in an incandescent light (to the same wall receptacle, not the backup unit itself) and observe whether it flickers.

If you used an extension cord to another room (for both the battery backup unit and the incandescent light) do you have the same problem?

The UPS is plugged straight into the wall without a cord, I have no incandesent bulbs available to be plugged in unfortunately, but I can safely assume it will flicker with an incandescent since there has been a time where the living room next to this room had the lights flicker as well.

More Power! 08-13-2011 03:42 PM

Quote:

Originally Posted by karnyboy (Post 706370)
Sag yes...it is dropping, thanks for the clarification, but I think you knew what I was referring to anyway.:thumbsup:

Indeed. Just helping you with the terminology :)

Anyway: As I noted earlier: We're going to need more info. Can't do more than pull guesses out of our back-sides with what you've given us.

dmxtothemax 08-14-2011 02:36 AM

It is difficult to say were the problems lie in your system,
We need to know more about the power supply system.
But it sounds like there are saggs in the supply,
Not always caused by you.
Could be other systems on the same source.
You said your room,
Are you in a house with others,
Or a duplex or a complex.
Tell us more.

karnyboy 08-14-2011 10:17 PM

Well it's a typical 120 VAC, not a real big house I believe it's a 200A panel and it's not over loaded (in case anyone wonders) and no, it's a regular home with this particular room in question having the problems.

However here's the kicker....those problems I mentioned haven't happened once today (Sunday)...Like my original assumption months ago was I was almost certain it's not from the house, but the frequency of it happening up until today was leading me otherwise. If it's not the house though what would I do to place a complaint?

dmxtothemax 08-14-2011 11:10 PM

Sounds like poco has problems,
You could report your problems to poco,
and see what they say.
But without some observations as to a pattern of the bad behaviour,
Then it is so much more difficult for them to help.

karnyboy 08-15-2011 06:00 PM

I appreciate the help I have gotten thus far anyway.

Unfortunately due to the infrequency of the issue (sags) it has been hard to pin point it, all I know are the details in front of me. It's the best I can do for the time being. :(

dmxtothemax 08-15-2011 08:53 PM

I would still talk to poco,
You might not get immediate action.
At least they will know that there could be problems in that area.
And if enough people say similair things,
Then action could follow.

bobelectric 08-16-2011 06:56 AM

If .9 volt sag is an issue, I would redo all the receptacles on that circuit. Or better ,run a dedicated line.

AllanJ 08-16-2011 07:21 AM

It may be worth investing in some incandescent bulbs and some extra small portable fixtures (table lamps).

Do you get sags on every circuit (try different receptacles in different rooms)?

Hmmm. Reminds me of a time my uncle had sag problems and he, being an electrical engineer, narrowed the problem down to being outside the house. The power company eventually found that the pole transformer was inadequate for the air conditioners that most homes had.

More Power! 08-16-2011 07:33 AM

The symptoms the OP reports are not consistent with anything sensible.

He claims the circuit sags to 88VAC with no load on the outlet. Now it's possible something else on the same branch circuit is dragging it down, but such a load would either trip a breaker or start a fire (loose connection overheating/arcing), I would think.

My thought would be a POCO problem, but the OP claims that no where else in the home are such problems experienced.

Troubleshooting is required. Lacking that: All anybody's doing it throwing darts blind-folded.


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