low voltage

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Senior Member
Re: low voltage

There really isnt a minimum value of voltage specified by the NEC. However, for proper operation of equipment, there should not be more than around 3% to 5% to drop from utility supply to the farthest device from the service.

If you reading 100-volts at the service, you definetly have problems. 110.3(B) of the 2002 NEC states that equipment shall be used in acordance with any instructions included in the listing or labeling.

If the utility supply is 120-volts nominal, the lowest acceptable would be around 115-volts.

Is this reading on each leg to ground, or just one phase? :confused:


Re: low voltage

Reading is 100 on one leg and 106 on the other. Is 100 volts low enough to damage appliances such as computers?

[ May 16, 2003, 08:08 AM: Message edited by: c12719 ]


Esteemed Member
Re: low voltage

Measure the open circuit voltage(no load). If it is the same, call the utility immediately.

If the open circuit voltage is normal 120 to ground, you have a serious problem. This problem has probably made itself known by now.

Is your meter accurate?
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