American Power Conversion Central Air Conditioning System 用户手册

Cooling Coil Coolant Temp 
High

• Check the chilled water supply temperature.
• Verify that the coil fluid coolant temperature high threshold is not set below 

the normal temperature of your chilled water supply.

Cooling Coil Coolant Temp 
Low

• Check the chilled water supply temperature.
• Verify that the coil fluid coolant temperature low threshold is not set above 

the normal temperature of your chilled water supply.

Cooling Coil No Coolant Flow

• Verify the flow from the chilled water supply.
• Verify that the chilled water supply isolation valve is open.
• Check the operation of the flow switch.
• Check the electrical connections to the flow switch.

Env Humidity High

• Verify that no supply air is fed directly into the return air stream.
• Ensure that the alarm delay is not set too low. The delay should be long 

enough to allow the humidity in the room to stabilize after start-up.

• Verify that the alarm threshold for the humidity of the environmental sensors 

(return or remote) is set above the humidify and dehumidify setpoints.

• Check the capacity output of the humidifier, and reduce it if required.
• Ensure that there is a proper vapor barrier within the conditioned space.
• Ensure that the dehumidify mode is enabled.
• Verify that the Module is configured and equipped for the dehumidify mode.
• Ensure that the dehumidify mode is not disabled because of an active 

customer input mapped to nonessential lockout. 

Env Humidity Low

• Ensure that the alarm delay is not set too low. The delay should be long 

enough to allow the humidity in the room to stabilize after start-up.

• Verify that the alarm threshold for the humidity of the environmental sensors 

(return or remote) is not above the humidify and dehumidify setpoints.

• Ensure that there is a proper vapor barrier within the conditioned space.
• Verify that the Module is configured and equipped for the humidify mode.
• Ensure that the humidify mode is enabled.
• Check the capacity output of the humidifier, and increase it if required.
• Ensure that the humidify mode is not disabled because of an active user-

defined input mapped to nonessential lockout. 

Env Temperature High

• Check whether the Module is cooling. Look for a temperature differential of 

15–20°F (8–11°C) between the supply and control (return or remote) 
temperatures.

• Ensure that there is no concentrated heat source in the return air stream of the 

Module.

• Ensure that the alarm delay is not set too low. The delay should be long 

enough to allow the room temperature to stabilize after start-up.

• Verify that the temperature alarm threshold for the environmental (return or 

remote) sensors is above the cool and reheat setpoints.

• Ensure that the cooling mode is enabled.
• Ensure that the cooling mode is not disabled because of an active customer 

input mapped to nonessential lockout.