Client doesn't trust their smart meter and wants me to verify its accuracy. They believe it's reading high because their bills increased after the old meter was replaced. How do I independently verify a smart meter's accuracy without relying on the utility's own test?
Verifying smart meter accuracy
You can't independently test the meter without the utility's cooperation — the meter belongs to them. But you CAN request a formal meter test, which the utility is required to perform under their tariff (usually free for the first test, and at customer cost for subsequent tests). The key is requesting the test in writing and asking to be present or to receive the detailed test results, not just a pass/fail. The test report should show the accuracy percentage at both light load and full load. ANSI standards require meters to be accurate within plus or minus 2%.
Derek's right — request the formal test. In the meantime, you can do a sanity check by comparing the client's total metered usage against their operational records. If the client knows how many hours their equipment runs and the nameplate ratings of their major loads, you can estimate what the usage SHOULD be and compare it to what the meter says. If the estimate and the meter are within 10%, the meter is probably fine. If there's a 20%+ discrepancy, something is wrong — and it might be the meter, the multiplier, or the client's understanding of their equipment.
Good approach. Going to request the meter test and do the sanity check calculation in parallel. If both point to the meter being accurate, at least the client will have confidence in the billing going forward.