home electrical problem

[washman9]

we have a 20 year old house with standard 200 amp electrical service. over the years we have added approx. 1000 sq. footage to house to the point where we are heating and cooling about 5000sq. ft with 3 seperate 2.5-3.5 ton, very new, HVAC units. we have a 100 amp sub panel in our new garage that pulls off the 200 amp main. when the air comes on and the compressor is pulling heavy amp draw, our interior lights dim just slightly and for just a moment. is this something to worry about and do i need to involve power company to look at bringing more amps to house?

 

[Eric H]

How far away from the transformer are you? Could be slight voltage drop from the sudden inrush over a long distance from the transformer.
Dimming lights can also be caused by a loose/bad/undersized neutral some where.
I highly doubt that you need increased service. I have 2 washes with 200 amp service that have 2 changers, 4 bays, shurvend, 8 three motor vacs(30 amps each), plus plenty of lighting. Never had the main trip.
Try asking here for more info: http://www.forums.woodnet.net/ubbthreads/postlist.php?Cat=&Board=UBB3

 

[JGinther]

Voltage drop = Current x Resistance. So when the inrush current is spiked (increased by about 10 times the rated current), the voltage will drop will increase. So if this is a new problem, it probably means there was a change in the resistance (like having an overcharged AC system, or a bad capacitor in the compressor motor). If the problem has been there ever since the unit was installed, they either undersized some wire, or didn't make a good connection. If you notice the problem on only one light circuit, you might try moving the breaker to the other leg, as the loads may not be balanced well. I would also double check the main connections - expecially the neutral. You could also have the power authority put in a power monitor.

 

[pitzerwm]

Hell, when my freezer kicks in sometimes the lights on that circuit dims. I wouldn't woory about it.