Problems with reduced voltage

[tonype]

With 100+ temperature on Friday, I inspected a home that consistently had voltage readings in the 109 to 112 range through out at the receptalces. I know that record usage was being experienced and some utilities reduced the voltage. The home in question was near the end of the line in the system - dead end street that borders a very large public tract of property.

I realize that short term, this would not pose a problem. However, are there any long term problems with respect to operation of appliances, etc should voltage be this low over a long period of time?

 

[Little Bill]

With 100+ temperature on Friday, I inspected a home that consistently had voltage readings in the 109 to 112 range through out at the receptalces. I know that record usage was being experienced and some utilities reduced the voltage. The home in question was near the end of the line in the system - dead end street that borders a very large public tract of property.

I realize that short term, this would not pose a problem. However, are there any long term problems with respect to operation of appliances, etc should voltage be this low over a long period of time?

Some things such as incandescent lights might not suffer much more than being dim. Other things like compressor motors in A/C units, refrigerators, etc. would certainly suffer from long term low voltage. If something else that used contactors would suffer too. A lot of different things can't handle low voltage for an extended period.

 

[tonype]

Some things such as incandescent lights might not suffer much more than being dim. Other things like compressor motors in A/C units, refrigerators, etc. would certainly suffer from long term low voltage. If something else that used contactors would suffer too. A lot of different things can't handle low voltage for an extended period.

What types of things occur internally? Overheating?

 

[infinity]

I don't see the voltages that you've posted as a problem. Resistive appliances would need a little more time to heat up. Large motor appliances like A/C compressors would still see a voltage in the 218-224 volt range which shouldn't be a problem.

 

[Little Bill]

What types of things occur internally? Overheating?

Among other things. Contactors can arc and burn, leaving them where they don't make good contact when the voltage is back to normal.

I don't see the voltages that you've posted as a problem. Resistive appliances would need a little more time to heat up. Large motor appliances like A/C compressors would still see a voltage in the 218-224 volt range which shouldn't be a problem.

I was only addressing what can happen with extending periods of low voltage and not the exact voltages he posted. But I have seen some contactors and compressors that wouldn't start good with voltages as low as 109V. Even seen contactors burn and either melt open or closed.

Edit: I've also seen some circuits that used 120V to operate a 12V or 24V DC circuit that when the voltage is much below, say 115V, the lower voltage stuff didn't work right and caused damage to what they were driving.

 

[hurk27]

About the only motors that would have a problem would be 230 volt motors being run on 208 as they are already at the bottom of their range 188 volts would not be good for them, but a 200 volt motor would not have a problem, motor pole slippage will slightly increase the amps the motor is pulling, but most motors should have some head room to play with if the design of the equipment was done correctly.