Unit installation

45
System Checkout:
• Check all operating pressures & temperatures and subcooling & superheat.
• Check liquid line sight glass. The refrigerant shall be bubbles-free clear liquid. Existence of bubbles indicates under
charged circuit.
• Check the compressor crankcase sight glass for oil level. It should be at or slightly above the center of this sight
glass while the compressor is in operation. If not, see below mentioned instructions on “Lubrication”.
• Safety controls are factory set and must be maintained at settings indicated on the wiring diagram.
• Check the water temperatures (both in and out) and water flow rate to ensure that unit is operating within the
specified limits. See below mentioned instructions on “System Water Flow Rate and Pressure Drop” for further
information.
• Check compressor spring suspension for any unacceptable waving.
• Follow the guidelines given in Start-up & Commissioning checklist provided in this manual to complete this work.
External Enabling:
To make the unit start and stop from a remote switch an EXEN (External Enabling) input is supplied:
• Unit must be set the first time in on status through the ON/OFF key (the green led should therefore be ON).
• The auto-restart mode should be selected in set-up (P22 = 1) to allow the system to remember its status even after
a loss of power supply.
• If the EXEN input is energised the machine is stopped (using the pump down procedures but without enabling the
multiple pump downs) and the display shows “LOCK: REMOTE OFF”.
• If the input is not energised the units run normally starting with the normal staging.
In OFF status - the green LED off.
If the EXEN input is energised the display shows “LOCK: REMOTE OFF”.
If the EXEN input is not energised the display shows regularly “SYSTEM OFF”.
To toggle the unit status from off to on and from on to off the ON/OFF key
should be normally used.
LUBRICATION
A properly operated unit should run with the compressor crankcase bottom warm to touch. Check oil level frequently
to see that a sufficient amount of oil remains in the crankcase. Compressor oil level can be checked by sight glass.
To make sure that proper oil level is observed, operate the compressor and oil level should appear within the sight
glass range. For further information on oil adding/charging, oil contamination etc., refer to the Maintenance Manual.
SYSTEM WATER FLOW RATE AND PRESSURE DROP
The quantity of chilled water being circulated can be estimated by determining the water pressure drop through the
cooler and reading GPM from the appropriate pressure drop curve. An alternate method of determined GPM is to
measure pressure difference from pump inlet to outlet and read GPM from pump curve.
During unit operation, water flow rate must not vary more than ± 5% from the design flow rate. The water flow switch
should be calibrated accordingly. The maximum and minimum water flow rates for all unit models and the pressure
drop chart are given below. The design and operating flow rates must be within this range.
ATTENTION
(