Troubleshooting - Greenheck DGX Installation, Operation And Maintenance Manual

Blower Does Not Operate
115 Vac across
terminals 102 and 101?
Yes
24 Vac across
terminals R and X?
Yes
24 Vac across
terminals G and X?
Yes
24 Vac across
terminals 6 and X?
Yes
24 Vac across
terminals 7 and X?
Yes
24 Vac across
terminals 8 and X?
Yes

Troubleshooting

No
Primary Fuses (FU6) or Secondary Fuses (FU7) Blown
Main Transformer (TR1) Defective
No
Main Transformer (TR1) Defective
No
Fire system contact (FSC) tripped
No
Optional Exhaust Fan Interlocks (ST2-ST5) Open
No
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)
No
Supply Fan Overload (ST1 OL) Tripped
(Reset and check motor amps, reference blower start-up #4)
(Replace - Reference maintenance section)
One or more legs of 3 phase is out
Note: At this time the supply contactor (ST1) should pull in passing
power to the supply motor and the blower should start.
32
Check Main Voltage
(See Blower Start-Up Step #1)
Main Disconnect (DS1) Off
(Turn Main Disconnect DS1 On)
(Replace Fuses)
(Replace Transformer TR1)
Secondary Fuse (FU8) Blown
(Replace Fuses)
(Replace Transformer)
Supply Switch (S2) Off
(Turn Supply Switch S2 On)
(Correct/Replace)
(Correct/Replace)
Freeze Protection (FZ1) Tripped
(Reset)
Broken Fan Belt
Defective motor or capacitor
(Repair/Replace)
Blown Motor Fuse
(Replace)
(Restore missing legs)