KRUEGER A Series User Manual

40
KHF - SERIES A FAN COIL UNITS
INSTALLATION, OPERATION, AND MAINTENANCE MANUAL
EC MOTOR (CONTINUED)
PROBLEM POSSIBLE CAUSE CORRECTIVE ACTION
EXCESSIVE
FAN NOISE
Motor mounting bolts loose Tighten motor mounting bolts.
Motor shaft bent Replace motor.
Motor bearing end of life
Disconnect power from unit. Verify motor rotates freely by hand with blower disconnected.
Note: EC motors may not rotate freely as the rotor aligns with the stator magnets.
Motor overloaded
Verify static pressure per system design. Use amp meter to verify motor amps. Disconnect power to unit.
Verify motor rotates freely with power disconnected. If not, replace motor.
Motor end of life Use amp meter to verify motor amps. Replace motor.
Dirty lters Verify lters. Replace as needed.
Obstructed airow Verify blower is unobstructed. Verify no duct obstruction. Verify dampers are full open.
Improper duct connections Verify ductwork is installed per SMACNA and ASHRAE guidelines.
Static pressure too low Verify static pressure per system design.
Improperly balanced system Verify airow through connected ductwork.
Fan wheel rubbing on fan housing Align wheel in housing.
Loose fan wheel Align and tighten.
Damaged fan wheel Inspect fan wheel to verify ns are not bent. Replace blower as needed.
Imbalanced fan wheel Inspect fan wheel. Replace as needed.
TROUBLESHOOTING (CONTINUED)
COOLING SYSTEM
PROBLEM POSSIBLE CAUSE CORRECTIVE ACTION
INSUFFICIENT
COOLING
Insucient airow Verify proper airow.
Dirty water coil Check cleanliness of water coil. Clean as needed.
[24V units] Drain pan oat switch fault
Verify operation of drain pan oat switch, if present.
Disconnect switch and use volt-ohm meter to verify continuity of switch and of wiring. Replace switch if faulty.
Cooling valve not operating properly Verify cooling valve opens with call for cooling. Verify all manual valves are open.
Insucient ow Verify liquid ow per system design.
Obstructed coil Verify coil is unobstructed. Verify all manual valves are open and have liquid ow through system.
[DX coils] Improper refrigerant charge Charge to proper cooling.
[DX coils] Insucient cooling liquid to coil Verify coolant ow in coil. Verify proper ow per system design.
No call for cooling. Verify cooling signal at 'Y' terminals. Verify thermostat setting/operation.
UNIT SWEATS
Air leak in ducts/unit Verify integrity of unit. Verify ducts are properly sealed.
Pipe insulation Verify pipes are properly insulated.
Damaged insulation Verify insulation at point of sweating.
Unconditioned air to unit Verify conditioned air to unit.
Drain pan is clogged Locate and remove blockage.

KRUEGER A Series Specifications

General

Brand	KRUEGER
Model	A Series
Category	Fan
Language	English