Greenheck ERCH - Energy Recovery Unit with Packaged DX (468151) - Manual (Page 44)

44
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
One or both
blowers turn off
intermittently and
back on after
about 2 minutes
Exhaust Only frost control sensors are tripping .
Adjust frost temperature sensor set point as
needed .
Energy wheel does
NOT turn
Air seals are too tight .
See Energy Recovery Wheel under Unit Start-Up
section .
“Economizer” sensors are operating .
Adjust temperature or enthalpy set points as
needed .
No power to wheel motor .
Make sure wheel drive is plugged in . Verify
power is available .
Wheel drive belt .
Check for loose or broken belts . Replace belts
(consult factory) .
VFD overload . (OL1 on readout)
Refer to VFD section . Compare motor amp
rating to setting in VFD . Adjust accordingly .
Energy wheel runs
intermittently
Wheel motor overloads are tripping, due to
rubbing between wheel and air seals .
Recheck air seals, make sure they are not too
tight . See Energy Recovery Wheel under Unit
Start-Up Section .
Excessive noise
or vibration
Fan wheel rubbing on inlet .
Adjust wheel and/or inlet cone . Tighten wheel
hub or bearing collars on shaft .
Bearings .
Replace defective bearings (s) . Lubricate
bearings . Tighten collars and fasteners .
Wheel out of balance . Replace or rebalance .
Loose wheel on shaft . Tighten wheel setscrew .
Loose motor or blower sheave . Tighten sheave setscrew .
Belts too loose . Adjust belt tension after 24 hours of operation .
Belts too tight .
Loosen to maintain a 3/8 inch deflection per
foot of span between sheaves .
Worn belt . Replace .
Motor base or blower loose . Tighten mounting bolts .
Buildup of material on wheel . Clean wheel and housing .
Bearing and drive misaligned . Realign .
Noise being transmitted by duct .
Make sure ductwork is supported properly .
Make sure ductwork metal thickness is sized for
proper stiffness . Check duct size at discharge
to ensure that air velocities are not too high .