Relay Module Delay Power Off Switch Control Board Electronic Component RD21F-C 220V Item Type: Relay ModulePower Supply Voltage: 220V AC (range 100V-250V wide voltage) Module Power Consumption: 0.8W (0 power consumption in standby mode) Load Capacity: 10A Output Form: Active output Action Life: >100,000 times (full load), no-load >10 million times Size (mm): Approx. 68 x 36 x 22mm / 2.7 x 1.4 x 0.9in Screw Hole: Center Distance: Approx. 63 x 31mm / 2.5 x 1.2in Hole Diameter: Approx. 3.2mm / 0.1in Terminal: 1. Connect live wire to L and neutral wire to N 2. The switch is connected to L, L2 3. The load is connected to the FAN end, N Time Range Setting: S2 is used to set the time value S2 is not welded up and down, which means 0-30 adjustable S2 is welded up and down, which means 0-300 adjustable S1 is used to set the unit S1 is not welded up and down, the unit is: second S1 is welded up and down, the unit is: minute  S1 S2  Scope Accuracy Disconnect Disconnect 0-30s 0.1s Disconnect Connection 0-300s  0.5s Connection Disconnect 0-30 minutes 2.0s  Connection Connection 0-300 minutes  20s The potentiometer has 10 divisions and the time is equally divided. Typical Application: 1. Delayed turn off of exhaust fan 2. Delayed shutdown of the cooling fan of the heating system 3. Delayed turn-off of stair lights 4. Other industrial control places