Greenheck IGX Series Installation, Operation And Maintenance Manual page 44

Problem: Evaporative Cooling Module Does Not Operate - Auto Drain and Fill Control
Is fan operating correctly?
24 VAC between terminals Y1 and C
24 VAC between terminal A2 and A1
on cooling relay (RC)?
24 VAC between terminals 62 and 61?
24 VAC between terminals 7 and 61?
Time ranges on auto drain timer set
correctly?
Auto drain timer in drain mode?
24 VAC between terminals 8 and 61?
Evaporative cooling module sump
filled?
24 VAC between terminals A2 and A1
on RA relay?
Line voltage at primary side of TR3?
115 VAC between terminals 102 and
101?
115 VAC between terminal 14 on RC
relay and 101?
115 VAC between terminals 116 and
101?
Evaporative cooling pump(s) (P1)
running?
44 Model IGX Make-Up Air
Troubleshooting
Evaporative Cooling
Yes
Refer to the Troubleshooting, Supply Fan.
No
Cool switch (S4) off. Turn cool switch (S4) on.
Cool switch not wired. Wire cool switch (S4).
Yes
No
If a cool switch is not required and a cooing inlet air sensor is
provided, place jumper from R to Y1 to allow the cooling to enable
based on the cooling inlet air sensor.
Optional inlet air sensor (TS4) holding. Adjust TS4 setting.
Reference Supply Fan, Start-Up.
Yes
No
Fan Interlock (ST1 or RF) open. Refer to Troubleshooting, Supply
Fan.
Auto drain transformer TR2 circuit breaker tripped. Reset
transformer circuit breaker. If circuit breaker continues to trip, inspect
Yes
No
circuit for improper wiring or grounding.
Auto drain transformer TR2 failed. Replace auto drain transformer.
Inlet air temperature below evap freeze protection sensor (FRZ)
set point. Allow inlet air temperature to rise above 55ºF.
Yes Evap freeze protection sensor (FRZ) not wired. Wire evap freeze
No
protection sensor.
Evap freeze protection sensor (FRZ) failed. Replace evap freeze
protection sensor.
Yes
Set time ranges to the values shown on the ladder diagram.
No
No
Yes Wait for the drain mode timer to expire (usually 10 minutes).
Auto drain timer (TC) wiring issue. Inspect and correct wiring issue.
Yes
No
Auto drain timer (TC) faulty. Replace auto drain timer.
Auto drain valves (VS,VD,VSD) not wired. Wire auto drain valves.
Yes
No
Auto drain valve(s) failed. Replace failed valve(s).
Yes
Wiring issue to RA relay. Inspect and correct wiring.
No
Yes
No Transformer fuses (FU7) blown. Check and replace blown fuse(s).
Transformer secondary fuses (FU8) blown. Check and replace
blown fuse(s).
Yes
Transformer TR3 wired incorrectly. Refer to wiring diagram on
No
transformer and correct wiring.
Transformer TR3 faulty. Replace transformer.
Yes Auto drain relay (RA) failure. Check for loose connections or bent
No
relay pins, repair or replace relay.
Yes Cooling relay (RC) failure. Check for loose connections or bent relay
No
pins, repair or replace relay.
Evaporative cooling pump(s) (P1) wired incorrectly or not wired.
Correct any wiring Issues.
Yes
No
Evaporative cooling pump(s) (P1) faulty. Replace evaporative
cooling pump(s).
Everything is working properly, consult factory.
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