Electrical Maintenance 8-19
TG-VI, MT µP-IV, µP-V, µP-VI, SR-2 or SR-3 Controller
The microprocessor uses relays to operate unit valves and solenoids. Each relay circuit is fuse protected. The relay board also
contains the CYCLE-SENTRY buzzer, remote light fuses, ammeter shunt and jumpers to configure the relay board for proper
operation.
NOTE: Refer to the appropriate Controller Operation and Diagnosis Manual for more specific relay board information for
your unit.
Typical Relay Board – SR-2/SR-3
1. K1: Run Relay
2. K2: Preheat Relay
3. K3: High Speed Relay
4. K4: Damper Relay
5. K5: D/E
6. K6: Fuel Solenoid Pull In
7. K7: Start Relay
8. K8: Electric Clutch Relay
9. K9: On/Off Relay
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