Greenheck ECV Series Installation, Operation And Maintenance Manual page 24

Troubleshooting – Unit
Symptom
Blown fuse or open circuit breaker.
Defective motor or capacitor.
Blower fails Motor starter overloaded.
to operate
Electrical.
Drive.
Control power (24 VAC) wiring run is too long
(resistance should not exceed 0.75 ohms).
Motor starters
"chatter" or
Incoming supply power is less than anticipated.
do not pull in
Voltage supplied to starter coil must be within
+10% / -15% of nominal voltage stated on the coil.
CFM too high.
Static pressures are higher or lower than design.
Blower rotation is incorrect.
Motor over amps
Motor voltage incorrect.
Motor horsepower too low.
Shorted windings in motor.
Unit damper not fully open.
System static pressure too high.
Blower speed too low.
Fan wheels are operating backwards.
Low airflow (cfm)
Dirty filter or energy core.
Leaks in ductwork.
Elbows or other obstructions may be obstructing
fan outlet.
Belt slippage.
Blower fan speed too high.
Filter(s) not in place.
High airflow (cfm)
Insufficient static pressure (Ps) (airflow resistance).
One or both
blowers turn off
intermittently and Frost control sensors are tripping.
back on after
about 2 minutes
Always have a completed Pre Start-Up Checklist, unit Start-Up Checklist, and Optional Accessories Checklist prior to
requesting parts or service information.
24 Energy Core Ventilator
Possible Cause Corrective Action
Replace fuse or reset circuit breaker and check
amps.
Replace.
Reset starter and check amps.
Check for On/Off switches. Check for correct
supply voltage.
Check for broken or loose belts. Tighten loose
pulleys.
Shorten wiring run to mechanical room or install a
relay which will turn unit on/off. Consult factory for
relay information.
Need to increase supply power or use a special
control transformer which is sized for the actual
supply power.
Check cfm and adjust drives if needed.
If higher, ductwork should be improved.
If lower, fan rpm should be lower.
Check rotation and reverse if necessary.
Check motor nameplate versus supplied voltage.
See specifications and catalog for fan curves to
determine if horsepower is sufficient.
Replace motor.
Adjust damper linkage or replace damper motor.
Improve ductwork to eliminate losses using good
duct practices.
Check for correct drives and rpm with catalog data.
For 3-phase, see Direction of Fan Wheel Rotation
under Unit Start-Up section.
Follow cleaning procedures in Routine Maintenance
section.
Repair.
Correct or improve ductwork.
Adjust belt tension.
Check for correct fan rpm. Decrease fan speed if
necessary.
Install filters.
Induce Ps into system ductwork. Make sure grilles
and access doors are installed. Decrease fan speed
if necessary.
Adjust frost temperature sensor set point as
needed.
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