dim lights

[enireh]

in the house when the ac kicks on the lights dim how can we stop that?

 

[480sparky]

Service size too small.
Service conductors too small.
Overloaded panel.
Undersized conductors to AC.
AC start capacitor out.
Loose connections in either / both AC and lighting circuits.
Compressor in AC going bad.

 

[gar]

161017-2335 EDT

enireh:

You make quantitative measurements along with some visual observations.

1. Turn virtually all loads in the home off. Don't worry about electric clocks, and minor other loads. Probing directly on the conductors (means putting the probe on the wire and not on the lug) entering the main panel, and measure the line to line voltage, each line to neutral voltage, and neutral to a screwdriver in outside earth.

2. Repeat the same measurements in min-max mode with a digital meter from before to just after the air-conditioner turns on.

3. Repeat the same measurements after the A/C inrush has dissipated.

4. Estimate the time duration of the major voltage dip whem the A/C turms on.

5. Try to estimate or read the kVA of the power company transformer. And the distamce from the transformer to the main panel.

Assuming the measurements are reasonable, then change lights to CFLs or LEDs that experimentally have a fairly constant light output with normal voltage variations.

.

 

[11bgrunt]

in the house when the ac kicks on the lights dim how can we stop that?

I have been involved in these complaints for a while now in new construction and the comments from gar and 480 sparky are certainly good suggestions to determine the cause of the voltage drop that you see.
Locally, when the VD does not exceed 3% from the POCO, they will not make any changes. When there is not a smoking gun or an economical fix, I have been using non dimmable LEDs. Brand didn't matter in my testing. At 15% VD the light did not flicker or change output that could be seen even when watching the bulb. I experimented with many different bulb types, wattages and brands. Long ago frosted incandescent was a way we suggested to make VD less noticeable.
My 2 cents.

 

[kwired]

in the house when the ac kicks on the lights dim how can we stop that?

Get a variable speed/soft starting AC system, or improve the voltage drop condition on the service, feeder, or possibly even the source.