Section 69-09-02-21 - Accuracy of watt-hour metersWatt-hour meters used for measuring electrical energy furnished to customers shall:
1. Be of proper design for the circuit on which they are used, be in good mechanical condition, and shall register correctly.2. Not creep at "no load". A meter shall be considered to creep when the load wires are disconnected, and potential is impressed, if the disk makes more than one full revolution in five minutes or less.3. Be accurate, when used on alternating current circuits, to within plus or minus two percent, at unity power factor, on light load (ten percent of meter reading) and on full load (one hundred percent of meter rating); and to within plus or minus three percent, at fifty percent lagging power factor, on full load (one hundred percent of meter rating).4. Be accurate, when used on direct current circuits, to within plus or minus two percent on light load (ten percent of meter rating) and on full load (one hundred percent of meter reading).5. If polyphase meters, have their elements in balance within two percent of full load (one hundred percent of meter rating) at unity power factor, and at fifty percent lagging power factor.6. If used in conjunction with instrument transformers, for which laboratory test records are available, be adjusted so that the overall accuracy of the metering installation will meet the requirements of this section.N.D. Admin Code 69-09-02-21
General Authority: NDCC 49-02-11
Law Implemented: NDCC 49-02-11