Chilled Water Pump Mismatch Alarm

For this function, it is necessary to connect the number of operating chilled water pumps from the chilled water pump sequencer module (SQA) to the input “OperChwPump”. When the chiller chilled water pump is commanded on, then the number of requesting chilled water pumps is increased by the output “ReqChwPump”. A chilled water pump mismatch alarm is generated if the number of “ReqChwPump” is greater than the number of operating chilled water pumps and the delay defined by ALM-04 has been expired. The chiller unavailable flag is set (chiller common alarm output) and the chiller shutdown sequence is started.

The chilled water valve alarm is displayed by DISP-04.

The alarm must be reset (manually or automatically) in order to start-up the chiller again.

Table 9.   Chilled water pump mismatch alarm behaviour

ALM-04

Chilled water pump mismatch alarm behaviour

>0

If the number of requesting Chilled water pumps is greater than the number of operating Chilled water pumps, after expiration of the alarm status delay

= 0

No monitoring is done and no alarms are generated


Table 10.   Parameter List

Description

Value Range

Default Value

Unit

ALM-04: alarm delay chilled water pump; 0=disable

0...3600

0

sec

DISP-04: chilled water pump alarm

0/ 1

0

-