Greenheck DG / DGX with Pilot Ignition (463555 IOM) (Pre-2008) - Manual (Page 34)

34
Troubleshooting
Troubleshooting
115 Vac between
terminals 102 and 101?
Check Main Voltage
(See Blower Start-Up Step #1)
Main Disconnect (DS1) Off
(Turn Main Disconnect DS1 On)
Primary Fuses Blown
(Replace Fuses)
Main Transformer Defective
(Replace Transformer) 24 Vac between
terminals R and X?
Main Transformer Defective
(Replace Transformer)
24 Vac between
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)
24 Vac across
terminals 5 and X?
24 Vac across
terminals 4 and X?
24 Vac across
terminals 3 and X?
Supply Fan Overload (ST1 OL) Tripped
(Reset and check motor amps, reference Blower Start-Up #4)
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)
Optional Exhaust Fan Interlocks (ST2-ST5) Open
(Correct/Replace)
Freeze Protection (FZ) Tripped
(Reset)