I have a customer with a high electric bill (300 to $400) with in no a/c or heat. Should be around $200. In Florida with a mild winter. Water heater elements are good. Did a amp check A-15 B-10. Can you read an earth fault with an amp probe? POCO said that was not the case. Would a service lateral faulting to earth in front of a meter cause the meter to read it?
Nothing in front of the meter will have an effect on the bill.
Without some kind of recording this is going to be difficult to pinpoint, but the first step I'd take would be to verify their existing loads by estimating monthly usage of what they have connected, then identify from the bill and/or from the POCO what kind of load you're looking for. Depending on their billing, you might have the last year's usage graphed out or the POCO may be able to give you that info. Once you have an idea of how much "extra" power is being used, you can calculate what you're looking for with an amp clamp. For example, if they're showing an extra 900 kwh per month, you'd be looking for a 1.25 kw load, so 1250 watts times their voltage (at 125V about 10A). If there's a leak to ground, you can expect this load to be more or less constant throughout the day. If it's not a leak, you would have a larger load cycling on at some interval (ex. 20A with a 50% duty cycle). Worst case scenario, you'll have multiple faults to identify. You'll likely have to monitor for some time to figure it out.
A simple, relatively inexpensive setup that would help is something I recently tested - a Bluetooth adapter for Agilent handheld DMMs that works with software for an Android device which allows you to datalog and graph the readings. You can connect up to three devices for monitoring, so you can log current on L1 and L2, plus voltage between L1 and L2 to get an estimate of watts. Seeing this graphed out can really help to identify certain kinds of faults. I recently found a leaking water system that was causing the customer's water pump to cycle on and off every four minutes with this. Here's a screenshot of about 1 1/2 hours of monitoring their service:
View attachment 6699
You can see the jump every four minutes that lasts for about 1 min. 20sec. At the rates the customer pays, just the cycling on and off costs them about $30 per month.
Agilent was running a promo (probably still is) on the U1177A Bluetooth adapter ($49 item) that gets you one for free with the purchase of a DMM, so theoretically you can get three DMMs with adapters for a little over $300 plus the cost of whatever Android device you get.
Good luck!
