The PGR-8800 is a UL and cUL listed arc-flash relay that reliably detects developing arc-flash incidents without nuisance tripping by looking for a combination of excess light and current. Phase-current-transformer inputs are provided for current-constrained arc-flash protection and when so equipped, a programmable definite time over current function can be enabled. An optical sensor on the PGR-8800 and adjustable trip level reduce the chance of nuisance tripping by setting A threshold for ambient light. Sensors, inputs and connections are monitored to ensure fail-safe operation. A secondary solid state trip circuit provides A redundant trip path. A USB port is used for configuration and access event logs and graphs.