Electrical Maintenance 8-18
RELAY BOARD
Typical Relay Board – µP-VI Controller
1. K1: Fuel Solenoid Pull-in Relay
2. K2: High Speed Relay
3. K3: Damper Relay
4. K4: Preheat Relay
5. K5: Starter Relay
6. K7: Run Relay
Typical Relay Board – Multi-Temp MT µP-IV
1. K2: High Speed Relay
2. K3: Damper Relay Zone 1
3. K4: Preheat Relay
4. K5: Starter Relay
5. K7: Run Relay
6. DFR: Damper/Fan Relay Zone 2
7. FR3: Fan Relay Zone 3