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keyser soze 05-29-2007 09:58 AM

Another quick questions for the experts
I've been having brownouts on some of my circuits. I haven't checked to see if all of the problematic breakers are on the same leg in the panel but I suspect they are.

Is there anything I can do about this? It just started about a month ago and was really bad the first time it happened and hasn't been quite as bad since. We had to turn off the washing machine until it passed because it was dimming the lights to about 50% :eek:. I have a power conditioner on my PC and it was reading low so I checked one of the outlets and it read 92-96 volts. :no: I checked a outlet on another circuit, 120. It is sporadic, not constant. Happens maybe once a week.

Low voltage is better (at least I think it is) than high voltage but I don't understand how this could just start up like this.


HouseHelper 05-29-2007 10:35 AM

If some circuits read 92-96V and others read 144-148V, you have a loose neutral connection at the meter, service drop, or transformer. If you are getting the lower voltage on one leg and 120V on the other, then you have a loose connection on that hot leg or a poor connection between the main breaker and the panel bus bar.
Start by contacting your utility company and having them check all their connections from the transformer to the meter. This should be a free service.

keyser soze 05-29-2007 12:19 PM

Good reasoning there. It was, IIRC, 90 something on one leg and 120 something on the other. It did not take the missing voltage from the one leg and add it to the other leg so to speak. I think before I even call the Power Co I'll double check the voltages next time it happens.

If it is a problem in my breaker panel I don't understand how it just started up out of nowhere (I hadn't been working in there for months before this started) but weirder things have happened. The electrician that installed breaker panel was a marvel of modern licensing. My wire pulling and J-boxes look 1000 times better than his but then again it's my house not his. Then again the inspector left the green tag on my door and did the "inspection" without going inside the house. :eek: He must have been having a good day.

Thanks a lot for your help!

jwhite 05-29-2007 04:36 PM

You cannot take the missing voltage number and expect the higher voltage reading to be that exact amount higher. Too much complex math would be involved here and would depend on the exact resistance of each device that was turned on at the time of the test.

the point is just that one goes high while the other goes low.

Insulting electricians will get you no graces on this site, unless you want truely professional advice from people with little more knowlege than you on the topic at hand.

It sounds like you are getting an open hot leg from time to time. The voltage you are reading when this happens is leaking through some 240 volt loads. Perhaps the hot water heater or oven.

You should not wait. Call the utility company and have them check all the connections from the transformer to the house panel. This situation could cause major dammage to your equipment.

keyser soze 05-29-2007 07:32 PM

I see... I don't think the other one was high at all but I'll call "Progress" Energy tomorrow to get them out here STAT just to be safe. If they try to say they are going to charge me for it I'll have to use my "business" tone with them. :wink:

Thanks JWhite, you are an asset to this forum. Yep, I'm saying that on day number two as a member. :thumbsup:

Not to be a PITA but what exactly does 'open hot leg' mean? I don't know all of the lingo but I do understand enough to wrap my head around it. Don't worry, I don't work on anything "upstream" from the main breaker. Inquiring minds want to know.

JohnJ0906 05-29-2007 07:56 PM

At your main service, you have 3 wires coming in. 2 lines, or "hots" and 1 neutral. L1, L2, N.
L1 to L2 = 240 volts
L1 to N = 120v
L2 to N = 120v
"open hot leg" would mean L1 or L2 is open.

keyser soze 05-29-2007 09:03 PM

okay, one more dumb question, what does "open" mean? Is this reffering to voltage? I imagine that I would check this at the termination points at the top of the panel (before any breakers). Now I'm really intrigued.

I understand what you say about the voltages at the panel. I actually already understood that part believe it or not. I do not know how to tell if it is "open" though. I do have a digital multimeter and understand how to use it so I could definitely tell if I knew what to look for.

Either way I'll be calling the CO tomorrow to get them to do their work first.

this forum kicks butt! :clap: At least I'm learning skills here instead of just wanting to spend more money like on my other forums.

jwhite 05-30-2007 07:04 AM

the two most common electrical problems are Open and Short.

Short is where a electrical connection is being made someplace where you do not want one. The breaker will usually trip.

Open is where a electrical connection is not being made where you want one. Corroded lug, cut wire, loose crip etc.

Turn off the main breaker in the main panel. the two lugs where power comes in from the utility will still be hot. Test from hot leg A to neutral, then from hot leg B to neutral. I am guessing one will show open.

Be carefull when using a digital bench type meter. You will get ghost voltages. Readings on the meter that mean nothing in real life.

keyser soze 05-30-2007 07:50 AM

Bingo! 10-4 loud and clear. That's what I thought but I didn't want to be a goober and assume anything.

As far as the multimeter is concerned I have noticed a little weirdness here and there when measuring the circuits around the house. I chalked it up to the $50 meter. I did go get a Greenlee since I've heard good things about them and I didn't want to cheap out on it too bad. I usually take the readings a couple of times and with a grain of salt. I just use it for basic stuff anyway like - Is there voltage? Is it 110 or 220? Is there continuity? Nothing major really. I just figured it was a step above the little pen-like "hot wire tester". Those things are almost worthless unless you have nothing else. I've found "hot" sheetrock in my house with one of those. :no:

I suppose it wouldn't hurt to go ahead and tighten the lugs on the Lines at the top of the panel if they are testing open? That would have to be the problem right? Is it possible for a wire (especially a big one like that) to be partially open? Maybe there's just not enough surface area making a connection to let all of the voltage pass though the lug? If it is actually just an intermittent open connection wouldn't I have to wait until a "brownout" was in progress, run out there and test it then? They have been really quick and short the past week or two. The light(s) will dim for a second or less (maybe to about 70-80% brightness) and then they will be okay for awhile. Sometimes they will dim quickly and for random lengths of time (short) maybe 2 or 3 times before they go back to "normal".

I remember there being a substance that looks like nickel "anti-seize" on the stripped ends of the lines. I've seen that on other panels so I figured that was SOP these days. Maybe the lug is tight and there needs to be more of this stuff? I figure it is just anti seize to avoid corrosion and facilitate loosening at a later date. I would think a copper paste would be better to provide more surface area for the connection (nickel is not supposed to be conductive). I bet this paste is different than what I suspect it is now that I think about it more.

Oh and thanks a lot for the super helpful, simple, and well worded explanation about open and short. "Light bulb over the head" big time here. Sometimes I think people (skilled tradesmen of any kind) like to keep things "secret" in hopes of job security or something. Anyway, thanks again!

HouseHelper 05-30-2007 08:02 AM

Unless you have a disconnect at the meter, the lines at the top of the panel WILL STILL BE HOT even with the panel main off and should not be touched. As stated earlier, if you have an intermittent open, it could be at the transformer, meter, main breaker lugs, or between the main and the panel bus. Call the POCO, rule out problems on their end, then call an electrician.

Just out of curiosity, what brand of panel (and what size) do you have?

jwhite 05-30-2007 08:09 AM

the meters that we electricians carry, outside a testing lab, are usually not accurate enough to detect a partial open.

What is more likley happening is that when a phase goes open, you are still getting a backfeed through a 240 volt appliance, like a stove or hot water heater. As I said this can cause dammage to equipment.

Do Not Try To Tighten The Main Connections Yourself. They ARE Still Live, Even With The Main Breaker Turned Off.

keyser soze 05-30-2007 09:32 AM

Thanks for the reminder about the lugs. I was being momentarily ignorant trying to speak about it from my office. I would have realized the stupidity of what I was saying were I looking at the panel.

Calling the power company once I submit reply.

Thanks for being patient with me guys.

And was I way off about the goo on the main lines? What is that crap?

The panel is a Cutler-Hammer 30/40 BTW. At least that's what I remember him calling it. 30 breaker slots with the bottom 10 being "tandem" breaker capable IIRC. I'm up to about 36 I think. I've started using the tandem breakers for the circuits that I'm adding. It doesn't help me save space when I've got so many dedicated 220 circuits (2 air handlers, 2 furnaces, dryer, water heater, etc). Oh well, sure beats the 60 amp fuse panel I started with. :blush:

Is the 30/40 big enough for a "normally" wired 3000 sq foot home? Most rooms have one lighting circuit, one outlet on each wall, then two lights in the baths (3). One kitchen, washer dryer etc. It isn't wired to the gills since I have to fish every single drop. I'm just trying to improve on the one outlet per room and keyless fixtures. The reason that I ask is that I will have about one blank left when I'm done. I assumed that if they made it that large it would be okay to fill it up (or almost in this case). Was I wrong?

jwhite 05-30-2007 09:50 AM

the goo is anti-oxidant. it is used on aluminum wire to help keep it from corroding.

It is ok to fill the panel up to its design limit. A typical 3000 foot house is on the edge of needing a sub-panel, or a larger than 200 amp service, depending on the other details.

20 spaces for two pole loads, 7 for 20 amp circuits and another 10 for general purpose lighting and recs would not be uncommon.

Gerry Kiernan 05-30-2007 10:30 AM

I,m no expert, but if the goo on your wire connections is an anti-oxidant for aluminum, is it possible that you have aluminum wiring? If so, your problem could be corrosion. If you have copper wiring, you could still have a corrosion problem. If your wire ends are not bright and shiny, but dull or discoloured, or even showing discolouration due to arcing, or high resistance, that could be an issue. The corrosion will increase the resistance at the connection, and as the circuit comes under more load, such as when the dryer goes on, the resistance at the connection goes up, and things can start heating up. I have no idea the age of your home, but if nothing else works, have a look at all your connections that you can get at, especially the panel ones, to see if there are any signs of corrosion, looseness, or overheating. If there are indications, the wires can be cleaned up with fine sandpaper, and reconnected. If you have aluminum [I hope not] be super careful with the wire handling, because aluminum becomes very brittle with age and working, and will readily break off.

Good luck


keyser soze 05-30-2007 10:46 AM

yep, sounds about like what I have with the addition of dedicated bathroom recepticles and the kitchen GFCI circuit. I'm not sure if that is "code" or suggested but I figured with the massive draw of hair dyers and space heaters that it wouldn't be the worst idea in the baths (GFCI outlets of course). I figured with the possibility of a splash in the Kitchen I did the same there.

As far as main service goes, as long as you aren't drawing more than 200 amps on a regular basis its okay right? I have only added a washer/dryer, lighting and about a dozen to fifteen outlets since the panel went in. No welder plugs (I use the range outlet for that) or massive air compressors or anything else that would be out of the norm. I suppose the main breaker would keep me from causing any damage from drawing too much amperage anyway.

Yeah I know I say words like 'assume' and 'suppose' a lot (might as well be four letter words). I'll try to work on that.

The power Co will be checking their side of everything this afternoon by the way. We'll see how that goes.

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