Model IGX Make-Up Air
40
®
Troubleshooting
Supply Fan
Problem:
Fan does not operate.
Line voltage across L1 & L2, L2 & L3,
and L1 & L3 on main disconnect (DS1)?
Yes
È
No
Æ
Main incoming power not connected
. Connect proper supply
power to unit.
Line voltage across T1 & T2, T2 & T3,
and T1 & T3 on main disconnect (DS1)
Yes
È
No
Æ
Main disconnect (DS1) open or defective
. Close, repair, or replace.
24 VAC across R and C?
Yes
È
No
Æ
Main transformer (TR1) circuit breaker tripped
. Reset transformer
circuit breaker. If circuit breaker continues to trip, inspect circuit for
improper wiring or grounding.
Main transformer (TR1) failed
. Replace main transformer.
Phase monitor (PM) contact open
. Correct incoming phase order at
disconnect.
Fuse (FU6) blown
. Test and replace blown fuse(s).
24 VAC across G and C?
Yes
È
No
Æ
Fan switch (S2) open or not wired
. Close or wire fan switch.
Fire system contact (FSC) tripped/not installed
. Correct or replace.
If fan switch and fire system contact is not required, place jumper
from R to G to make the fan run continuously.
24 VAC across A2 and A1 on the RF
relay?
Yes
È
No
Æ
Freeze protection tripped
. Cycle disconnect to reset.
Supply fan overload tripped
. Push reset button on overload or VFD
to reset. Check motor amp draw and correct as necessary.
Damper limit switch (D1L) not closed.
Damper stuck closed or actuator failed
. Repair damper
interference or replace actuator.
Exhaust fan contactor not powered
. Close or wire exhaust switch,
reset exhaust overload, or replace faulty exhaust contactor.
24 VAC across A2 and A1 on the
supply contactor (ST1)?
Yes
È
No
Æ
RF relay failure
. Check for loose connection or bent relay pins, repair
or replace relay.
Line voltage across L1 & L2, L2 & L3,
and L1 & L3 on supply starter (ST1)?
Yes
È
No
Æ
Supply motor fuse (FU1) blown
. Test and replace blown fuse(s).
Line voltage across T1 & T2, T2 & T3,
and T1 & T3 on supply starter (ST1)?
Yes
È
No
Æ
Supply starter contact (ST1) not closed
. Replace contactor.
Line voltage across T1 & T2, T2 & T3,
and T1 & T3 on supply starter overload
(ST1OL)?
Yes
È
No
Æ
Supply overload (ST1OL) faulty
. Replace overload.
Is motor operating?
Yes
È
No
Æ
Motor wired incorrectly
. Check and correct motor wiring.
Defective motor/capacitor
. Repair or replace.
Is the fan operating?
Yes
È
No
Æ
Broken fan belt
. Replace. Reference Maintenance, General, V-Belt
Drives.
Everything is working properly, consult factory.
Problem:
Too much airflow.
Fan speed too high?
No
È
Yes
Æ
Adjust drives or VFD as needed.
Reference Supply Fan, Start-Up.
Filters in place?
Yes
È
No
Æ
Install filters.
Insufficient external static pressure?
Yes
Æ
Increase external static pressure.
Everything is working properly, consult factory.