When I remodeled my house I upgraded the electrical service to 200 amps and added several circuits, one of which was for an additional room and another for HVAC. The lights in the addition (laundry/utility room) dim or flicker when the refrigerator (another circuit, another room) comes on, when the HVAC compressor comes on, or when the washer or dryer or anything plugged into that circuit is turned on.

What's the fix and is there more here than irritation?

Hi Tee,

When you upgraded to 200 amp, did this include upgrading the utility feeds to your house or did you just change your breaker panel?

Did you have double circuits on the old panel that you reconnected the same way in the NEW 200-ampere Panel.

Sounds to me like you doubled up on the circuits on the same circuit breakers when you went to your NEW 200-Amp Panel.

This will cause the symtoms that you describe.

The wiring for each circuit should be on a separate circuit breaker.

Also, as Walks on Water's said, make sure that the size wire coming from the feeder is sized properly.

For 15-ampere loads the wire should be AWG No.14 copper.

For 20-ampere loads the wire should be AWG No.12
copper.

For 30-ampere loads the wire should be AWG No.10 copper.

Any load of 30-amperes or more should be a dedicated circuit for one individual type load. That is, like a Garbage Disposal, a Dryer, a Washer, a Range or an Air conditioner.

Electric Ranges, must be on a 50-ampere dual circuit breaker.

Most Electrical Dryers, must be on a 40-ampere dual circuit breaker.

Also, depending on what you went from to what you have now, i.e. the 200-ampere Panel, you must also increase the feeder wires coming from the Power pole all the way to the top of the Circuit Breaker Panel to AWG No. 3/0 copper. This is extremely importent.

If you only had a 100-ampere panel the largest the wire size would have been is AWG No.3.

If you only had a 60-ampere panel the largest the wire size would have been is AWG No.6.

Neither of these wire sizes are any where near large enough for the 200-ampere panel.

[This message was edited by donaldekliros on 06-19-02 at 10:30 AM.]

First, let me say that I am no electrician. I only know the bare minimum. (Not too bad at framing and finish, though.) So let me try to answer the questions you guys raised.

I don't believe the wire from the pole to the weather head was changed, but from the weather head to the box was upgraded.

I'm not sure what you mean by doubling up on the circuits. Several new circuits were added with lights and outlets separated, HVAC on a dedicated circuit, and heavy-draw appliances on dedicated circuits. Washer and dryer (gas) are on the same circuit as the outlets in the utility room. The utility room lights are the only ones that dim and they are on a circuit which includes the kitchen lights (4 75-watt bulbs), utility room lights (two 2x 75-watt fixtures), and exterior lights (4 150 watt fixtures and not often used).

I have no 30 amp 110 circuits and all wire was replaced with 12-2 except for the 220 circuits which is, of course, heavier.

Someone suggested that there may be something loose on the neutral bar, but I checked that and all is secure.

Remember, the only lights that are affected are those in the utility room.

What did I leave out?

To Teeceeum:

Sounds to me as though you have the refigerator & the utility lights on the same circuit or that there is a cross between them that is causing the circuits to act like it is one circuit.

If the refrigrator is indeed on the same circuit with the utility lights it would cause your utility lights to dim when the motor was getting up to full speed.

Until the motor gets up to full speed it is like a short circuit momemtarily & draws a heavier current than at full speed & this would cause the utilty lights to dim.

If this is the case you must install the refigerator on a dedicated circuit with probably a 15-ampere circuit breaker.

What I meant when I said doubling up of the circuit is that you connected two circuits to the same circuit breaker.

You said the wire from the weather head to the power panel box was upgraded. What size wire did you install?

AWG No. 3/0?

If NOT then you better increase its size, otherwise, you are going to waste power on I^2R losses in the cable. This will increase your electric bill.

If the wire from the weatherhead to the power pole has not been increased in size to AWG No. 3/0, its affect will be the temperature of the wire will go way up. Especially if it is Aluminum wire which it more than likely is.

This wont affect your electric bill but it is a hazard that could cause a fire in the future or cause your service to be disrupted if the wire should fatigue & break into.

[This message was edited by donaldekliros on 06-19-02 at 10:32 AM.]

teeceeum:
First off follow all of Don's excellent suggestions.

In regards to you mentioning a possible break in the neutral, this would cause some definite and obvious symptoms.

1. Lights may dim way down as a load like the refrigrator comes on and never come back to full brilliance.
or
2. Lights may flare brighter that normal as the 'fridg comes on.

If either of these are what's occuring let us know, in the mean time do as Don advises and you should be fine.

Regards
Mike B. (AKA Byter)

[This message was edited by donaldekliros on 06-19-02 at 10:34 AM.]