Rule 17

Each watt-hour meter shall be tested according to the following schedule and adjusted whenever it is found to be in error more than 1 per cent., the tests both before and after adjustment being made at approximately three-quarters and one-tenth of the rated capacity of the meter. Meters operated at low power-factor shall also be tested at approximately the minimum power-factor under which they will be required to operate. The tests shall be made by comparing the meter, while connected in its permanent position, on the consumer's premises with approved, suitable standards, making at least two test runs at each load, of at least 30 seconds each, which agree within 1 per cent.

Single-phase, induction-type meters having current capacities not exceeding 50 amperes shall be tested at least once every 4 months and as much oftener as the results obtained shall warrant.

All single-phase induction-type meters having current capacities exceeding 50 amperes and all polyphase and commutator-type meters having voltage ratings not exceeding 250 volts and current capacities not exceeding 50 amperes shall be tested at least once every 12 months.

All other watt-hour meters shall be tested at least once every 6 months.

Rule 20. Request Tests

Each utility furnishing metered electric service shall make a test of the accuracy of any electricity meter upon request of the consumer, provided the consumer does not request such test more frequently than once in 6 months. A report giving the results of each request test shall be made to the consumer and the complete, original record kept on file in the office of the utility.