American Power Conversion Central Air Conditioning System manual Troubleshooting, Problem

Models: Central Air Conditioning System

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Troubleshooting

Troubleshooting

Problem

Possible Cause

Corrective Action

 

 

 

Controls are erratic

• Incorrect secondary voltage.

• Ensure that the control transformer secondary

or inoperative

 

voltage is within +/- 10% of 24 VAC.

 

• Remote shutdown input is

• Check the event log for an entry in the log that

 

cycling the Module on and

indicates remote shutdown activity.

 

off.

 

 

 

 

Evaporator motor

• Control circuit breaker is

• Reset the control circuit breaker.

fails to start

tripped.

 

 

• Frequency Drive is in an

• Check the event log for a VFD alarm entry.

 

alarm condition or has failed.

Replace the frequency drive.

 

 

 

Humidifier

• Humidifier circuit breaker

• Check for short circuit. Reset the circuit breaker.

inoperative

tripped.

 

 

• Water supply strainer may be

• Remove and clean the strainer.

 

clogged.

 

 

• Improper water supplied to

• For proper operation, the humidifier requires a

 

humidifier.

regular water supply. Any treated water

 

 

(demineralized, softened, or ionized water) will

 

Non-essential lockout has

result in improper humidifier operation.

 

• Review the event log to see if this alarm input has

 

been activated by a user-

been activated.

 

defined input with the

 

 

equipment.

 

Reheat elements

• Circuit breaker is open.

inoperative

Non-essential lockout has

 

 

been activated by a user-

 

defined input with the

 

equipment.

Check for direct short circuits. Reset the circuit breaker.

Review the event log to see if this alarm input has been activated.

Airflow too Low

• External static pressure is too

 

high.

 

• The pressure drop across the

 

chilled water coil is below

 

the recommended value.

 

• Cooling setpoint is too low.

Try to compensate by increasing the blower speed to match recommended coil pressure drops.

Raise the Module to the minimum height or add duct transitions to direct the air across the floor.

Check the chilled water coil pressure drop through the display interface. Pressure should match recommended pressure drops indicated on the chart based on Module size. If the pressure drop is below the recommended settings, increase the blower speed until the pressure drop matches the recommended setting. See “Calibrate airflow manually” on page 17.

Verify that the cooling setpoint is not below 68° F (20° C).

NetworkAIR IR Operation, Maintenance, and Troubleshooting

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American Power Conversion Central Air Conditioning System Troubleshooting, Problem, Possible Cause, Corrective Action