A 120/240/277/480 voltage change switch is provided with an “OFF” position in order that the load can be de-energized without the necessity of breaking connections when it is desired to make adjustments to the meter under test. The various load values are changed by manipulation of a durable rotary switch. No connections need to be changed. The unit provides a 5, 15 and 30 amp current source at full load and a .5, 1.5 and 5 amp current source on the light load setting. Power factor can be easily switched between 50% and 100% via a simple, durable toggle switch and each of the 3 phases can be de-energized without the need to disconnect the leads via independent switches.

The artificial load and standard are permanently connected and the internal connections of the load are such that the movement of the load selector switch automatically places the proper standard coil in the test circuit. Standards can be easily removed from the unit if desired for calibration. For open-link meter testing, please see Catalog No. 621 Field Test Kit.