North Dakota Administrative Code › Title 69 - Public Service Commission › Article 69-09 - Public Utility Division › Chapter 69-09-02 - Standards of Service - Electric › Section 69-09-02-25 - Meter testing equipment

Current through Supplement No. 393, July, 2024
1. Each
				utility shall maintain sufficient laboratories, meter testing shops, secondary
				standards, instruments, and facilities to determine the accuracy of all types
				of meters and measuring devices used by the utility.
2. Each utility maintaining primary standards
				such as precision wattmeters, volt boxes, resistances, and timing devices shall
				have such standards certified at the time of purchase as to accuracy by a
				recognized laboratory other than that of the manufacturer of the
				standard.
3. Utilities not
				maintaining standardization laboratories may obtain authorization from the
				commission to have their standards certified for them by an approved
				laboratory.
4. Secondary watt-hour
				meter standards shall not be in error by more than plus or minus three-tenths
				of one percent at loads and voltages at which they are to be used, and shall
				not be used to check or calibrate working standards unless the secondary
				standard has been checked and adjusted, if necessary, within the preceding
				twelve months. A history and calibration record shall be kept for each
				secondary standard watt-hour meter.
5. Any two or more of at least three
				watt-hour meters may be used as a secondary standard to check portable rotating
				standards provided there is no discrepancy in accuracy between any two of the
				watt-hour meters used by more than two-tenths of one percent at standard test
				loads. Calibration and history records shall be maintained for each of the
				meters used as secondary standards.
6. Secondary standard indicating instruments
				shall not be in error by more than plus or minus one-half of one percent of
				indication at commonly used scale deflections, and shall not be used to check
				or calibrate portable indicating instruments unless the secondary standard has
				been checked and adjusted, if necessary, within the preceding twelve months. A
				calibration record shall be maintained for each standard.
7. All working rotating standards, when
				regularly used, shall be compared with a secondary standard at least once a
				month if they are of the commutator type, and at least once in every six months
				if of the induction type. Working rotating standards infrequently used shall be
				compared with a secondary standard before they are used.
8. Working rotating standards shall be
				adjusted, if necessary, so that their accuracy will be within plus or minus
				three-tenths of one percent at unity power factor, and within plus or minus
				one-half of one percent at fifty percent lagging power factor at all voltages
				and loads at which the standard may be used. A history and calibration record
				shall be kept for each working rotating standard.
9. The meter accuracies herein required for
				all primary, secondary, and portable standards shall be referred to one hundred
				percent. Service measuring equipment shall be adjusted to within the accuracies
				required assuming the portable test equipment to be one hundred percent
				accurate; provided, that a utility may use calibration records to compensate
				for known errors of secondary standards and working standards in adjusting
				service measuring equipment.
General Authority:
NDCC
					 49-02-11
Law Implemented:
NDCC
					 49-02-11