i-Gard’s SIGMA 3 relay is a combination ground fault and monitoring relay with pulsing capability, that fully complies with the requirements of the Canadian Electrical Code 2021 section 10.302 without exception or rating restrictions.

The SIGMA 3 is designed for application in High Resistance Grounding systems (systems typically below 5kV where the fault current is limited to 10 amps or less) and the complete range of Low Resistance Grounding systems (systems between 5kV and 69kV where the NGR is time rated).