Removal and replacement procedures 16
4.
Remove the control relay module (2).
Replacing the control relay module
1.
Align the control relay module with the mounting and power connections.
2.
Slide the module until it clicks into the DIN rail.
3.
Reconnect all wiring to the control relay module.
Differential pressure sensor
The HP POD 20c uses differential pressure sensing terminals located in the ECS cabinet to take pressure
readings from the cold aisle, hot aisle, and cooling fan filters via sensing tubes. The terminal determines
cold-to-hot aisle differential pressure and filter differential pressure for all three cooling zones.
You need a small wrench to remove and replace the differential pressure sensor.