C405.6 Electrical Transformers
Low-voltage dry-type distribution electric transformers shall meet the minimum efficiency requirements of Table C405.6 as tested and rated in accordance with the test procedure listed in DOE 10 CFR 431. The efficiency shall be verified through certification under an approved certification program or, where no certification program exists, the equipment efficiency ratings shall be supported by data furnished by the transformer manufacturer.
Exception: The following transformers are exempt:
MINIMUM NOMINAL EFFICIENCY LEVELS FOR 10 CFR 431 LOW VOLTAGE DRY-TYPE DISTRIBUTION TRANSFORMERS
|SINGLE-PHASE TRANSFORMERS||THREE-PHASE TRANSFORMERS|
|kVAa||Efficiency (%)b||kVAa||Efficiency (%)b|