Sense labs - Voltage dip - Lights pulse

Hi everyone, question for the experts if I may.

I have an issue which I believe I should likely contact my local electricity provider to check on however wanted to check in with the group to see if perhaps I am making an issue of nothing.

When one of two large draw appliances starts (electric dryer and/or central air conditioner), a pulse is seen in the overhead lights throughout the home. I can visually see these dips in the Sense Labs power quality section however doesn’t register as a dip as I suspect they are not large enough.

My direct question, is this normal behaviour for large appliances with a high inrush surge to dim lights which are on separate circuit? The house has a 200 amp service with approximately 29 circuits (of which the AC unit and dryer are in their own dedicated).

If I remember correctly those devices are targeted to dim devices at about 5%, which is barely noticeable. If you have a bad capacitor or a motor in one of those devices that’s starting to fail it can pull upwards to 40% which will make it much more noticeable.

I would have a routine maintenance performed on the AC unit and they can test the capacitor at that time. If it’s a capacitor that’s going bad they are relatively inexpensive and easy to replace. If it’s a motor, compressor or other component then it’s a bit more.

If it really bothers you and everything checks out you can ask someone to install a “hard-start kit” which would make it so you don’t notice it at all.


Andrewsimkins… Not an expert…hi… First I would ask has it always been like this or did it just start happening recently?? If recent, a problem may have come up on the appliance. Next, If It has been this way for sometime… How long is the service (cable) from the transformer to your service panel?? Around here some people have regretted getting underground when the run is 2-300 foot long from the transformer being on the road and the service being that long. They get a little dimming of the lights when 220 high current drawing appliances come on… The power company didn’t up a pole (primary feed) in closer to the house because the customer didn’t want it for all the trees on the property… My 2 cents… Gerry

Hi there, thanks for the reply. The house is 2 years old, and this is not a new issue. The closest pad mounted transformer is about 150 feet away.

Andrewsimkins… Here is something you could try that should be very easy.

Go to your Sense… Tabs on top screen go to the ‘LABS’…Pick the ‘Power Quality’… See what you have for the Min / Max Voltages… This could get tell you something… Later…Gerry…

Send you a pic of the screen in a couple of minutes…

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