IEEE C37.20.6 2015 Edition, February 16, 2015
4.76 kV to 38 kV Rated Ground and Test Devices Used in Enclosures
This standard covers drawout-type, indoor, medium-voltage ground and test (G&T) devices for use in drawout metal-clad switchgear rated 4.76 kV through 38 kV as described in IEEE Std C37.20.2™.1 Four G&T device types are generally supplied for temporary circuit maintenance procedures for insertion in place of the circuit breaker as follows:
a) Simple manual devices
b) Complex manual devices
c) Simple electrical devices
d) Complex electrical devices
There may be more complicated G&T devices that may include current and/or voltage transformers, glow tubes, or other accessory components. These more complex devices are not covered by this standard. Due to their complexity, additional testing and interlocking are required, and manufacturers should be consulted for the availability and ratings of these types of devices.
Although G&T devices have been used as accessory devices in metal-clad switchgear for decades, they were not addressed in the standards until IEEE Std C37.20.6™-1997 was approved. This is because they are specialized accessory devices, designed and tested in accordance with applicable sections of circuit breaker standards, and based on user-unique operational requirements. This revised standard complements IEEE Std C37.20.2 and addresses the more common G&T device types. This standard also clarifies that G&T devices are not required to have the interrupting and continuous current ratings of the circuit breakers they may temporarily replace for the purpose of grounding and testing medium-voltage circuits. It also recognizes that some devices may be offered with interrupting capabilities, and required tests for such devices are specified.