APC ACSC100 User Manual

Fans fail to start

• Cooling Unit shutdown due 

to an external command

• Temporarily remove the user contact cable, if it is 

connected.

• Single fan fails to start

• Confirm that the fan is seated properly and fully engaged. 
• Replace the fan if it is faulty.

Cooling unit cannot 
achieve setpoint

• Improper placement of 

remote temperature sensor

• Verify that the remote temperature sensor is properly 

located in the IT rack.

• Dirty filter

• Clean the filter.

• Dirty coil

• Clean the coil.

• Application error

• Contact APC Worldwide Customer Support at a number on 

the back cover of this manual.

• Heat load is too far away

• Place the cooling unit closer to the heat load.

Water carryover

• Improper fan speed selected 

• Select the next highest fan speed setting. For example, 

change the fan speed setting from Low to Med/Low.

• Room humidity is too high

• Adjust setpoint on dehumidifying equipment.
• Add additional dehumidifying equipment.

• Dirty coil

• Clean the coil. 

• Dirty filter

• Clean the air filter.

• Room humidity is too high

• Adjust setpoint on dehumidifying equipment.
• Improve room sealing.

Cooling unit noise 
level is higher than 
expected

•  Improper fan speed selected

• Select a lower fan speed.

• Incorrect placement of rack 

inlet sensor

• Verify that the rack inlet sensor is properly located in the 

cold aisle.

Temperature control 
not precise enough

• Improper placement of 

remote temperature sensor

• Verify that the remote temperature sensor is properly 

located in the IT rack.

Water outside of 
Cooling unit

• Condensate drain hose is not 

connected or not properly 
routed outside the cooling 
unit

• Verify that the condensate drain hose is properly connected 

to the pump and properly routed outside of the cooling unit.

• Verify that the condensate drain line does not exceed 4.9 

meters (16.0 feet) lift and 15.2 meters (50.0 feet) horizontal 
run.

• Leak in drain system

• Locate and repair the leak.

• Cooling unit not leveled 

properly

• Adjust the leveling feet of the cooling unit.

• Damaged piping insulation

• Identify damaged area and repair the insulation.