The answer is for someone to show a little intelligence and put a volt meter on it - preferably a recording meter. I think you will find an open or high resistance neutral.

At any rate, they need to take voltage readings while your a/c is cycling. The electrician should have done this.

Your breaker panel could also be improperly balanced. If there's to much on the phase the lights are on they dim.

Your PoCo is obligated to provide you power within tolerance. Call them and request that they send out a tech to put a logger on your service. It will monitor line voltage and current, they'll leave it for a day or two,hopefully. Make sure you intentionally duplicate the fault and write down what you did and when, not every light, but the loads causing the problem. They'll come back, retreive the logger and the tech MAY download the data right then, and maybe you can track it down.

No matter waht else is going on in the subdivision, they are obligated to provide you reliable, safe power.
I,ve run into this, usually on three phase,though, a local plant or factory will fire up at the beginning of a shift, aweak transformer craps a little, or a local cap bank fires a little too late, and the voltage goes through the roof,or craps out, if only for a second or two, but it's pretty significant and enough to fault the smarter equipment. Like I said, usually not in Resi, but who knows, they have already blamed each other, so why not try.

The fact that the lights go BRIGHT, first is what makes me think it's PoCo. Lights usually go bright when the line voltage goes up.

I'm not saying there couldn't be a fault in your home, but there's probably still a bunch of temp power further into the subdivision, and god only knows how their balancing their loads (RIGHT)

KEN

The only thing can cause the lights to go bright is a loose neutral. This can have very serious effects on your electronics.

"The only thing can cause the lights to go bright is a loose neutral"

I don't know about that.........

Columbus said that they've checked that. Usually when the PoCo starts pointing fingers, it's to buy time.

If the house is 5 years old, assuming the A/C was in new, the loads are probablt pretty equal.

That is nott to say a loose neutral could NOT cause this, it could, but we're told this has already been checked.

The other tip-off is that the PoCo guy said " it's getting everything we're sending it" What??? What does that mean? It means wiggies across the lines, and "Every thing's fine here, Sir!"

What if it wasn't "getting everything we're sending it"?

Huh? Where did it go? This isn't plumbing....

And Columbusgardener, a couple questions, how far is it to each of the nearest two transformers from your house, meaning up and down the street, and maybe, if you're out for a walk, and sharp enough, you could count the transformer drops, unless it's under ground, meaning how many homes are they feeding from each transfomer. When subdivisions are being built, at least aroung here, there is a little "give and take" ;)

And, always the best clue, ask your neighbors about any anomalies they have...

And, I JUST thought of this, is this a NEW problem?

KEN

brand new problem - as of last tuesday

my neighbors are less than neighborly - but I will call go around and ask

as for transformers my line ( going backwards ) from house to box ( underground) up a pole - on which there are "fuses" that have blown several times since we moved in. out to the main street and then connect to lines. there are several poles with one green garbage can looking thing - the problem in the lines run off the main street into other subs and they are all underground. The line that comes into my backyard goes underground out to the other homes in sub - all underground and are now about 35 homes -

as to checking the neutral - the electrician checked everything in the panel

it's as bad today as it was last week I am only lighter in the wallet

you know when he said that we were getting what they were sending - he checked their side of the meter (244) and our side (245) I assumed he meant that it wasn't the meter so it was my problem to fix...

The only thing can cause the lights to go bright is a loose neutral"
I don't know about that.........

Columbus said that they've checked that. Usually when the PoCo starts pointing fingers, it's to buy time.

POCO are notorious for needing two or three calls to find problem like this. The only thing that can cause brighter lights when something starts up is a loose neutral. Problem could be anywhere from the breaker box back to the transformer. Could be the main nutral connection inthe panel, the meter can, the weatheread, at transformer. Did the POCO open the meter and check the connections?

The significant voltage readings with a loose neutral are the (nominal) 120 volt circuits. The reported 244 and 245 (assumed to be volts) will not confirm nor deny the existence of a loose neutral. Spend 50 dollars and get two of the meters at the link. Plug into different receptacles. Try to select receptacles that are on different poles of the service.

Here is a link that might be useful: Meter

My experience is mostly Industrial, heavy commercial.

Less neutrals there ;).

So I'd go with the resi guys, but I still think it could be a transformer problem, and that is certainly one of the places a poor neutral would cause this.

And I'd be interested to find out what has caused the fuses to pop, and are the fuses right at the transformer?

If there's a loose/poor neutral at the transformer, and many 220/240 loads are cycling simultaneously, on like on a hot day, the fuses may pop. If there's an autorecloser instead on it, a self-resetting circuit breaker, so to speak, you would loose power, either on one or both legs, momentarially, and then it would come back. Most of us have probably experinced this. Does this happen often at your house?

The fuses shouldn't just be popping this often.

So I'm back to POCO, but loose POCO neutral. Now were all steering the same way.

The transformer would probably be the green garbage can,with some wires coming from the wires higher up ont pole and some going to the lower ones, unless others are around underground,etc.

KEN

Explain to me how the neutral is involved in 240 volt single-phase loads. If it is involved, enlighten me. If not involved, why confuse by bringing it into the picture?

Just thougth I'd throw this in. It's from the PSNH (Public Service of New Hampshire) Website. It's actually the first time I've seen it. Although I live in NH, I'm not on PSNH, I'm NGrid. It;s a bit to read and the chart got skewed pasting it, but I'm not patient enough to fix it, but you can probably decipher it. But this is their baseline, and they clearly state that it may go outside of it, either way, for many reasons, so....

"PSNH Service Voltage Requirements
Like any electric utility power supply, the voltage on PSNH's system will vary throughout the day largely due to the variation in customer electricity use. Under normal conditions, PSNH's secondary voltage service levels are supplied in accordance with the NH Public Utilities Commission requirements. These requirements are based on industry standards set by the American National Standards Institute. The rules governing utility voltage standards do provide several exceptions to these voltage limits. These exceptions are conditions that:

Arise from adverse weather conditions;
Arise from the operation of customers equipment
Arise from utility equipment failures;
Arise from circuit switching equipment during emergencies;
Are causes beyond the control of PSNH.
Even though PSNH endeavors to maintain constant voltage to your service point, your equipment must be prepared to expect occasional deviations outside the nominal ranges.

PSNH Voltage Limits
(Average voltage for 2 minutes)
Nominal Voltage
Minimum Voltage
Maximum Voltage

120/240 114/228 126/252
120/208 114/197 126/218
277/480 263/456 291/504

Types of Electrical Disturbances
Electrical disturbances, a form of distorted electrical power, come in many shapes and sizes. Electricity as it comes from the generator is smoothly flowing and shaped like successive waves cycling up and down 60 times per second. Distorted electricity can be caused by electrical equipment in your building or in neighboring buildings, as well as by events on the utility system.

Research by the Electric Power Research Institute and others has confirmed 70 to 80 percent of the disturbances originate in the customerÂs building or factory. These disturbances are caused by equipment interaction and are often exacerbated by wiring and grounding problems.

The remaining 20 to 30 percent of the electrical disturbances that affect equipment originate on the utility system. These disturbances are caused by a number of factors including weather (lightning, rain, or fog), tree or limb contacts, accidents (dig-ins, vehicles hitting poles), and utility equipment failure.

Electrical disturbances interact with the system in several ways. First, something must cause the electrical disturbance such as a large motor starting or a lightning strike. Next, the wiring network, which carries the disturbance to other equipment, may aggravate the disturbance. Finally, the disturbance reaches electronic equipment which reacts to the disturbance. Listed below are the most common types of disturbances, typical causes, and impacts.

Transients: Also known as surges or spikes, these are caused by lightning, appliances such as printers and copiers, as well as utility activities such as circuit breaker operation and switching. Transients of sufficient energy can upset computers, corrupt data, or even cause damage to power supplies and components.

Sag: A brief drop in the voltage (electrical pressure). Sags can be caused by equipment such as motor starting, and heaters in printers and copiers cycling, as well as utility events. Sags often cause lights to dim or flicker and computer equipment to lock up or lose memory.

Swell: A brief increase in the normal voltage level. Most swells are caused when a motor stops. Although not generally a problem, swells have been known to cause failure of marginal components in electronic equipment.

Over and Undervoltage: Longer-term increases or decreases in the normal voltage. These disturbances often indicate an overloaded transformer or circuit, or the misoperation of a voltage regulating device.

Momentary Outage: Also called a "momentary".This type of power outage is generally caused by utility protective equipment operation when trees, animals, vehicles, lightning or others contact the utility wires or striking the utility pole.

Harmonics: Harmonics are a regular distortion of the voltage waveform often caused by the power supplies of electronic equipment. Harmonics can cause overheating in transformers, building wiring, and motors.

Noise: Electro Magnetic Interference (EMI) is electrical interference caused by electric and magnetic fields emanating from electrical equipment, typically transformers or wiring. One impact often seen is a wavy computer screen.

Noise - Radio Frequency Interference (RFI) is electrical interference from equipment that radiates high frequency electrical energy such as TV/radio transmitters and cell phones. Interference can also be caused by arcing sources (switches) or switching power supplies such as those found in electronic ballasts and adjustable speed drives. This kind of noise often causes interference to control circuits."

Sorry so long, but the PoCo here is adnitting 20-30% of the faults are theirs....

And their range is 5% UP AND DOWN, under normal conditions, that will fault smarter drives, etc.
A 460 drive will almost always fault if it sees 504.
They'll only commit, kinda, to a 48V window....

I know the stuff I'm talking about is up at 460/480 so the percentages make bigger windows, but the math is the same at all the voltages..

One little pull, and.........

If your cut-out fuses are popping, it's definitely WAY outside this, WAY....

I know I'm way out of my lane here, but I wanted to show you why I suspect PoCo power. And, Yes, I have dealt with this, and argued, and the loggers have proved me right about 95% of the time. After you check all your gear.....
But again this was 3phase, so if the resi guys tell me to shut up, I will.

Thanks

KEN

well yesterday I called PoCo and retold them the situation - and asked if they could come and put a logger on it - the rep asked me why I thought there was a problem and not a regular dim ( reg dim I wasn't aware that the dimming of lights was regular) so I told her how at 4 am I wanted to print off my paper work when the printer started the tv turned off. She asked me to turn everything off and she would have someone here in the hour. True to her word they showed up and he went to work taking apart the meter and checking.

In the end he said that he could not find a ground going to the meter. I now have a copper wire from the box in back of my house to the meter on my deck. So far so good - no dimming and nothing has shut off.

Thank you for all of your help - you gave me enough information to ask questions and demand that they take action.

Ground going to the meter would not cause this problem. Sounds like the neutral from the meter to your main panel is the problem. The ground simply paralleled the defective neutral and is now carrying the neutral current. It shouldn't be.

The POCO might have correctly repaired the problem. joed is in Canada. In the USA, the POCO calls the grounded conductor in their single-phase service a "neutral" and the premises neutral and equipment grounding conductor do not become distinct until the first panel after the meter.

"( going backwards ) from house to box ( underground) up a pole - on which there are "fuses" that have blown several times since we moved in"

"In the end he said that he could not find a ground going to the meter. I now have a copper wire from the box in back of my house to the meter on my deck. So far so good - no dimming and nothing has shut off."

When you say "the box in back of my house" is this a ground level big "box" not attached to your house, on a concrete pad?

He might have a transformer right in his yard.Which would explain the cut-out fuse(s) at "his" pole with no pole mounted transformer there.

Did they add the "ground" from transformer to meter?????

Columbus said this was a new problem.... Did someone eat the missing "ground" last week???

KEN