Greenheck ERCH - Energy Recovery Unit with Packaged DX (468151) - Manual (Page 43)

43
Energy Recovery Unit with Packaged DX
Always have a completed Pre-Start-Up Checklist, unit Start-Up Checklist, and Optional Accessories Checklist prior to requesting parts or
service information.
Troubleshooting – General Unit
Symptom Possible Cause Corrective Action
Blower fails to
operate
Blown fuse or open circuit breaker .
Replace fuse or reset circuit breaker and check
amps .
Defective motor or capacitor . Replace .
Motor starter overloaded . Reset starter and check amps .
Electrical .
Check for On/Off switches . Check for correct
supply voltage .
Drive .
Check for broken or loose belts . Tighten loose
pulleys .
Motor starters
“chatter” or
do not pull in
Control power (24 Vac) wiring run is too long
(resistance should not exceed 0 .75 ohms) .
Shorten wiring run to mechanical room or install
a relay which will turn unit on/off (C/F for relay
information) . Increase wire gauge size so that
resistance is .075 ohms or less .
Incoming supply power is less than anticipated .
Voltage supplied to starter coil must be within
+10% / -15% of nominal voltage stated on the coil . Need to increase supply power or use a special
control transformer which is sized for the actual
supply power .
Motor over amps
CFM too high . Check cfm and adjust drives if needed .
Static pressures are higher or lower than
design . If higher, ductwork should be improved .
If lower, fan rpm should be lower .
Blower rotation is incorrect . Check rotation and reverse if necessary .
Motor voltage incorrect .
Check motor nameplate versus supplied
voltage .
Motor horsepower too low .
See specifications and catalog for fan curves to
determine if horsepower is sufficient .
Shorted windings in motor . Replace motor .
Low airflow (cfm)
Unit damper not fully open . Adjust damper linkage or replace damper motor .
System static pressure too high .
Improve ductwork to eliminate losses using
good duct practices .
Blower speed too low .
Check for correct drives and rpm with catalog
data .
Fan wheels are operating backwards .
For 3-phase, see Direction of Fan Wheel
Rotation under Unit Start-Up section .
Dirty filter or energy wheel .
Follow cleaning procedures in Routine
Maintenance section .
Leaks in ductwork . Repair .
Elbows or other obstructions may be
obstructing fan outlet .
Correct or improve ductwork .
Belt slippage . Adjust belt tension .
High airflow (cfm)
Blower fan speed too high .
Check for correct fan rpm . Decrease fan speed
if necessary .
Filter(s) not in place . Install filters .
Insufficient static pressure (Ps) (airflow
resistance) .
Induce Ps into system ductwork . Make sure
grilles and access doors are installed . Decrease
fan speed if necessary .