Radon mitigation fans installed on the exterior of buildings must be hard-wired into an electrical circuit.
Electrical disconnects shall be installed within line of sight and within 4 feet of the fan.
Exteriorly, plugged fans must used only inside of weather-proofed fan housings or weather-proofed chases.
An electrical disconnect switch or circuit breaker shall be installed in radon mitigation system fan circuits to permit deactivation of the fan for maintenance or repair.
Disconnect switches are not required with plugged fans.