Airedale Condensing Units (CU) 3kW - 80kW - Manual (Page 20)

CUS 15 - 60 / HCU 20 – 30D
Condensing Units
Chiller & Condensing Units
Installation & Maintenance:Part No: 6259592 IM 07\14
20
Commissioning Procedure
REFRIGERATION CIRCUIT -PRE-START CHECKS
Electrical 1 Check all electrical connections are tight, including contactor and all terminal
connections.
2 Check supply is available at the correct voltage and that any external fuses /
circuit breakers are the correct rating.
3 Check that there is a proper earth connection to the condensing unit.
4 Check that there is a supply to the oil sump heater.
IMPORTANT Scroll compressors in range CU30 to 60D and HCU30D condensing units:- Check
phase rotation of electrical supply prior to running compressor as compressor is
direction sensitive.
Refrigeration 1 Check that there is a holding charge of refrigerant in the system.
2 Check the high and low pressure switch settings. These should be as
follows:-
HIGH PRESSURE SWITCH 27 Bar (400 psi ) - CUT OUT
LOW PRESSURE SWITCH 0.5 Bar (7 psi ) - CUT OUT
3.8 Bar (55 psi ) - CUT IN
REFRIGERATION CIRCUIT - CHARGING
Procedure The system should be charged in accordance with accepted good practice and the
suction and discharge pressures should be constantly monitored whilst charging is in
progress.
At the same time the compressor current should be monitored.
The system should be charged to the relevant suction and discharge pressures,
together with the correct suction superheat (normally 5
° C to 6 ° C).
Once this has been done, all the readings taken should be recorded on the
commissioning sheets and a copy returned to Airedale for warranty purposes.
HEAD PRESSURE
CONTROLLER
ADJUSTMENT CUS 15 - 30D AND HCU 20 - 30D
The head pressure is controlled by a single head pressure controller fitted with two
pressure transducers - one to each circuit.
The fan speeds will increase if either head pressure goes above the preset level as
the fans are common to both condenser coils.
Access to the controls for this head pressure controller is achieved by removal of the
plastic cover which is secured by four screws.