Lights flicker with neighbor's AC

[7474]

Thanks in advance.

What would possible causes and solutions be to my lights flickering when my neighbor's AC turns on?

Thanks

[Mstrav]

Have you seen the commercial when the guy is in his garage trying to figure out what a wall switch controls and as they pan out, the neighbors garage door is opening and closing on her car? Its prob one of those thing, or your compresor is over amping ready to go.

[JstTrkin]

There is no Long electrical cords from your house to the neighbors by chance huh?

One thing I would try is shutting off your main breaker and while your neighbors A/C is running, make sure your meter isn't moving....

[mark beiser]

It probably is because both of your houses are served by the same transformer, and that when his AC starts, it causes a brief voltage drop for both of you.
Are these old houses with old electrical service?

Or if you have high electric bills all the time, and your neighbor has low ones, now you know why...
I'm only half joking about that bit. I have run into a situation in Duplexes where both outdoor units got their power from the service for one side of the duplex, and it was like that from the time the place was built.
It was discovered, more than 10 years after construction, when someone moved out of one side and had the power disconnected.
The person in the still occupied side called me for service. I had a heck of a time trying to figure out witch one of his breakers was for the outdoor unit, only to discover none of them were, cuz the wire was run to the wrong panel, lol.

[7474]

It probably is because both of your houses are served by the same transformer, and that when his AC starts, it causes a brief voltage drop for both of you.
Are these old houses with old electrical service?

Or it could be like that commercial someone mentioned...

New construction, roughly one year old. Had electric company out to inspect transformer. Was told the transformer serves 3 house (each roughly 3100 sqft) and has "more than enough voltage for the 3 houses" and there was no drop in voltage from the box to the meter on my house with a load applied.

[The Penguin]

this has to d owit hthe distance you and your neighbour are located from the pole transformer

when the unit starts du to the distance its from the pole the voltage drops on the circuit if your home and the neighbours home is on the same circuit - you will have the problem too.

your hydro co should be able to resolve this - might cost some bucks though

[l•k]

she might have done it

[gonekuku]

I would measure your home's incoming voltage before, during and after your neighbor's AC turns ON. You can do this from any outlet in your house. If you find an outlet without a load in the same circuit, your test results will be more accurate.

You need a precise quality meter for this (i.e. Fluke). A meter that will show voltage changes in less than one second. Lets say you measure 120.0 VAC when the neighbor's AC is off. Observe if this voltage dips when or after their AC turns ON. I believe any dip over 2% could be a violation of the 2005 National Electrical Code. Please check with your electrician.

I would suspect you and/or your neighbor has undersized wiring somewhere, possibly even from the street to your service panel.

I would call several electrical companies and ask them what they think. Have one inspect your service wiring etc. If they find something wrong (Undersized wire, shared homerun to the transformer), Contact the builder, developer, city with a written document showing the observations / possible problems and question who installed it & inspected it.

[7474]

I would measure your home's incoming voltage before, during and after your neighbor's AC turns ON. You can do this from any outlet in your house. If you find an outlet without a load in the same circuit, your test results will be more accurate.

You need a precise quality meter for this (i.e. Fluke). A meter that will show voltage changes in less than one second. Lets say you measure 120.0 VAC when the neighbor's AC is off. Observe if this voltage dips when or after their AC turns ON. I believe any dip over 2% could be a violation of the 2005 National Electrical Code. Please check with your electrician.

I would suspect you and/or your neighbor has undersized wiring somewhere, possibly even from the street to your service panel.

I would call several electrical companies and ask them what they think. Have one inspect your service wiring etc. If they find something wrong (Undersized wire, shared homerun to the transformer), Contact the builder, developer, city with a written document showing the observations / possible problems and question who installed it & inspected it.

Thanks for the replies both serious and humorous...I hope that "Life is not coming at me fast."(the commercial)

The city electric company stated that there was no drop on the line from the box to the meter when they tested it.

The HVAC company will be out today for routine maintenance, I will follow-up with them as well as the builder's electrician. However, I may need to find "independent" people to look at my complaint (however, the electrician has been one of the best subs to work with throughout this process, along with the HVAC guys of course)

[skippedover]

Make sure all the grounding is good. New homes typically have a plastic water main and that main was the old standby for the ground. If there's a plastic water main to the house, then a solid ground rod needs to be present for grounding. Having said that, the depth of the rod needs to reach moist ground. If it's just stuck in the sand, that's a problem. Some towns have special ordinances about such things because of dry ground. We've seen it around the beaches in our neck of the woods. Goes without saying that the neutral needs to be solid as well. Usually with a faulty neutral, you'll get dimming of the incandescent lights in the home, especially noticable when you're not looking directly the light. If you've got flourescents in the house, you won't generally see any change. But with a meter plugged into an outlet, turn a few things on or off in the home and if there's a bad neutral, you'll see the voltage change.

[7474]

Make sure all the grounding is good. New homes typically have a plastic water main and that main was the old standby for the ground. If there's a plastic water main to the house, then a solid ground rod needs to be present for grounding. Having said that, the depth of the rod needs to reach moist ground. If it's just stuck in the sand, that's a problem. Some towns have special ordinances about such things because of dry ground. We've seen it around the beaches in our neck of the woods. Goes without saying that the neutral needs to be solid as well. Usually with a faulty neutral, you'll get dimming of the incandescent lights in the home, especially noticable when you're not looking directly the light. If you've got flourescents in the house, you won't generally see any change. But with a meter plugged into an outlet, turn a few things on or off in the home and if there's a bad neutral, you'll see the voltage change.

Thanks for the reply. The neutral was something that the electrician from the city electric company mentioned. He thought it would be a good idea for the builder's electrician come back out to tighten all of the neutrals in the service panel.

Additionally, does using the push-in terminals versus the screw terminals on an outlet/switch have any effect on this problem? (I may have to find an electrician talk forum!!!!)

Thanks again.

[Craftsman]

Your house wouldn't happen to be a prior "model home" shown to the public for the sale of the project?

[7474]

Your house wouldn't happen to be a prior "model home" shown to the public for the sale of the project?

No, why do you ask?