The Cooling Circuit Controller; Blocking Cooling - Danfoss DHP-R 7Ua User Manual

2�5�3 The cooling circuit controller
A cooling circuit is used to move the cold from the cooling tank to where it is
needed. A shunt valve and a controller keep the temperature on the cooling
circuit constant. This controller has settings for set point, P-area, and I-time.
The HPC-CM module has inputs for a humidity sensor that measures both
room temperature and relative humidity. When connected, the dew point con-
trol can be activated. The control system will then calculate the dew point, and
if necessary raise the cooling circuit set point to avoid condensation.
2�5�4 Blocking cooling
The cooling circuit can be blocked by low outdoor temperature. A tempera-
ture limit, with hysteresis, blocks the use of active cooling. Another limit blocks
passive cooling. When passive cooling is blocked, the cooling circuit controller
and circulation pump are stopped. The circulation pump is exercised at regular
intervals.
Danfoss – 17