ok i have a weird one here. 120/208v 60a service to a small apartment suite. the customer has been paying approx. $40 per month for electrical usage. suddenly the customer is now paying just under $100 per month. my apprentice and myself checked all voltages. we checked at the main disc, meter stack and the apartment panel. all are identical. phase A to neutral 123v, phase B to neutral 123, phase C to neutral 123v. hots to ground just a slight bit lower like maybe 1/2 volt. phases to phases 213v. i realize that these voltages are a little high but i don't think that they are high enough to affect anything. there hasn't been any other complaints about high power bills from any of the other tenants. does anybody have an idea as to what is going on? oh yeah, the tenant has not changed anything in the suite.

Check for Hot water heater that is stuck on, Freezer stuck in defrost mode, outside HVAC equipment constantly running, etc.

LarryC

Has the meter been recently changed by the local authority? This happened to me once the old meter had been running slow possibly for a long time the LA came by and changed it all of a sudden the client saw his bill double.

How often is the meter read?

I got a very high bill a while back and it turned out that they estimated usage most of the time, only reading the meter 1-2 times per year. The high bill was a "correction"