Section PSC 113.0917 - Phase-shifting transformers and loss compensators(1) For phase-shifting transformers in service, all terminal connections shall be in such condition as to provide good electrical contact and the terminal designations shall be clearly visible. Where there is evidence of physical damage or evidence of thermal overload the unit shall be replaced.(2) Phase-shifting transformers shall be tested on the same schedule and at the same time as the meters with which they are associated. The test shall consist of a single-phase test to be performed as follows: With the approximate rated voltage applied to the input terminals and no burdens connected to the tap terminals all tap voltages, converted to percentage of input voltage, shall agree within plus or minus 2.0% of the theoretical values given in the manufacturer's published data.(3) In addition, all units shall be tested before use and when returned to the utility's meter laboratory. For these tests the output-voltage values in terms of percentage of input voltage and under the conditions of sub. (2) immediately above shall agree within plus or minus 1.0%.(4) For transformer-loss compensators in service all terminal connections shall be in such condition as to provide good electrical contact and the terminal designations shall be clearly visible. Where there is evidence of physical damage to the component parts, their adjustments, or to the internal wiring or evidence of thermal overload on the insulation, resistors, terminals, etc., the affected parts shall be replaced or the entire transformer-loss compensator replaced.(5) Transformer-loss compensators shall be tested on the same schedule and at the same time as the meters with which they are associated.(6) The tests shall be made at the normal service test points of the meter. Performance deviations from desired performance shall not exceed plus or minus 0.3%.Wis. Admin. Code Public Service Commission § PSC 113.0917
CR Register, July, 2000, No. 535, eff. 8-1-00.