Greenheck DGX - Troubleshooting Guides; Blower and Heater Faults

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Troubleshooting
115 Vac across
terminals 102 and 101?
Check Main Voltage
(See Blower Start-Up Step #1)
Main Disconnect (DS1) Off
(Turn Main Disconnect DS1 On)
Primary Fuses (FU6) or Secondary Fuses (FU7) Blown
(Replace Fuses)
Main Transformer (TR1) Defective
(Replace Transformer TR1)
24 Vac across
terminals R and X?
Secondary Fuse (FU8) Blown
(Replace Fuses)
Main Transformer (TR1) Defective
(Replace Transformer)
24 Vac across
terminals 8 and X?
Supply Fan Overload (ST1 OL) Tripped
(Reset and check motor amps, reference blower start-up #4)
24 Vac across
terminals 7 and X?
Damper Limit Switch (DL1) Holding
(Wait for actuator to open fully or adjust limit switch)
Damper Limit Switch Jumper Missing
(Install jumper, reference the units ladder diagram for terminals)
24 Vac across
terminals 6 and X?
Optional Exhaust Fan Interlocks (ST2-ST5) Open
(Correct/Replace)
Freeze Protection (FZ1) Tripped
(Reset)
24 Vac across
terminals G and X?
Supply Switch (S2) Off
(Turn Supply Switch S2 On)
Fire system contact (FSC) tripped
(Correct/Replace)
No
No
No
No
No
No
Yes
Yes
Yes
Yes
Yes
Note: At this time the supply contactor (ST1) should pull in passing
power to the supply motor and the blower should start.
Yes
Blower Does Not Operate
Broken Fan Belt
(Replace - Reference maintenance section)
Defective motor or capacitor
(Repair/Replace)
Blown Motor Fuse
(Replace)
One or more legs of 3 phase is out
(Restore missing legs)
Troubleshooting