Indiana Administrative Code
Title 170 - INDIANA UTILITY REGULATORY COMMISSION
Article 4 - ELECTRIC UTILITIES
Rule 1 - Standards of Service
Section 1-8 - Average accuracy of watthour meters; tests
Current through September 18, 2024
Authority: IC 8-1-1-3; IC 8-1-2-4
Affected: IC 8-1-2
Sec. 8.
(a) The accuracy at light load shall be determined at a load of approximately ten percent (10%) of the rated test amperes of the meter. The accuracy at full load shall be determined at a load of one hundred percent (100%) of the rated test amperes of the meter. For meters used with current transformers:
Average percentage registration is the average of the percentage registration at light load (LL) and at full load (FL). Thus, average percentage accuracy = (FL + LL) ÷ 2.
(b) The accuracy at light load shall be determined by taking the average of at least two (2) tests, which tests must agree within one-half of one percent (.5%) unless the meter has been tested by an automated device in which case one (1) test will be sufficient. The accuracy at full load shall be determined in a like manner. The average accuracy of the meter shall be determined by taking an average of the accuracy at light load and of the accuracy at full load. However, the average "as found" accuracy of a meter may be determined from one (1) light load test and one (1) full load test if:
(c) After any meter has been adjusted, the "as left" accuracy of the meter shall be determined by tests at each load as outlined in subsection (b).