KRUEGER A Series User Manual

36
KHF - SERIES A FAN COIL UNITS
INSTALLATION, OPERATION, AND MAINTENANCE MANUAL
PSC MOTOR
PROBLEM POSSIBLE CAUSE CORRECTIVE ACTION
NO AIRFLOW
[PSC MOTOR]
No demand Verify thermostat or control is calling for heating or cooling.
Fan speed is not commanded Verify fan run command is present at ‘g’ terminal of fan relay board (24v units) or of terminal block.
No power to motor; possible blown fuse or open circuit
breaker
Verify line voltage at motor terminals. Replace fuse or reset circuit breaker.
Incorrect voltage applied Verify proper voltage to unit per unit label.
Improper wiring connections
Verify wiring. If fan coil relay board present, verify all jumpers and harnesses installed.
Refer to fan coil relay board troubleshooting guide.
Fan speed adjustment outside operating range
If fan speed controller present, adjust fan speed control screw to full clockwise position.
Verify that motor starts. Reduce adjustment.
[24V units] three speed switch in o position Verify three speed switch, if present, is set to desired speed.
[24V units] loss of 24v power Refer to fan relay board troubleshooting guide.
[24V units] drain pan oat switch tripped
If drain pan oat switch installed. Verify drain pan is not full. Verify operation of oat switch.
Adjust switch position if needed.
[24V units] drain pan oat switch fault
Verify operation of oat switch, if installed. Disconnect switch and use volt-ohm meter to verify continuity of
switch and of wiring. Replace switch if faulty.
Low temperature cutout has tripped
If low temperature cutout present. Examine coil for signs of freezing. Verify adjustment of freeze stat.
Disconnect switch and use volt-ohm meter to verify continuity. Replace switch if faulty.
Blower jammed
Remove power from unit. Clear blockage.
Verify blower is not damaged and rotates freely while motor is not energized.
Failed motor capacitor
If motor hums or buzzes but does not start. Disconnect power from unit. Discharge capacitor. Remove motor
capacitor from circuit. Use analog volt-ohm meter to verify motor capacitor. Set meter to kilo-ohms scale. Touch
probes to capacitor terminals. Needle will jump to zero ohms then drift back to high ohms. Steady high ohms or
stead low ohms indicates failed capacitor.
Motor seized Remove power from unit. Verify motor rotates freely by hand with blower disconnected. If not, replace motor.
Damaged motor harness Replace motor harness.
Motor overloaded
Verify motor is not overheated. Check to ensure blower rotates freely with motor disconnected. Verify proper
duct static. Wait for motor to cool down and verify motor start. If motor overheats again, replace motor.
POOR AIRFLOW
PERFORMANCE
[PSC MOTOR]
Lack of required external static pressure External static pressure not as designed. Adjust external static pressure to design pressure.
[24V units] three speed switch in wrong position. Verify three speed switch, if present, is set to desired speed.
Poor voltage quality Verify input voltage within acceptable parameters.
Fan speed control adjustment outside fan operating range
If fan speed controller present. Adjust fan speed control screw to full clockwise position. Verify airow.
Reduce adjustment to speed that provides desired performance.
Improper duct connections Verify ductwork is installed per SMACNA and ASHRAE guidelines.
Duct obstruction Verify no obstructions. Verify all dampers are full open while fan operates.
Improperly set dampers Verify proper inlet air to unit.
Dirty coil Check cleanliness of coil. Dirty coil ns will restrict airow.
Dirty lters Check for dirty or blocked lters. Replace as needed.
Damaged or blocked blower Verify blower rotates freely. Clear blockage.
TROUBLESHOOTING (CONTINUED)

KRUEGER A Series Specifications

General

Brand	KRUEGER
Model	A Series
Category	Fan
Language	English