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PREPARATION
Commissioning of this unit should only be
carried out by Johnson Controls Authorized
personnel.
The unit On/Off switch beneath the key pad in the
electronic section of the control panel has been set to
the Off position at the factory. This switch must remain
in the Off position, preventing running of the unit until
commissioned by Authorized personnel. If the switch
has been set to the On position before commissioning
then it must be reported to Johnson Controls otherwise
the warranty may be void.
PREPARATION - POWER OFF
The following checks should be made with the customer
supply/supplies to the unit switched OFF.
Inspection: Inspect unit for installation damage. If
found take action and/or repair as appropriate.
Refrigerant Charge: Units are normally shipped as
standard with a full refrigerant operating charge. Check
that refrigerant pressure is present in both systems and
that no leaks are apparent. If no pressure is present a
leak test must be undertaken, the leak(s) located and
repaired. Repaired systems must be evacuated with a
suitable vacuum pump/recovery unit as appropriate to
below 100 microns before charging.
Do not charge liquid refrigerant with static
water in the heat exchanger. Care must also
be taken to charge liquid refrigerant slowly
to avoid excessive thermal stress at the
charging point.
Once the vacuum is broken, charge with the full
operating charge as given in Technical Data section.
Liquid subcooling measured at the liquid
line should be between 9.0ºF and 14ºF when
unit is operating in cooling mode and fully
loaded. Subcooling is determined by the
level of refrigerant charge in each system.
Valves: Ensure that the compressor discharge and
suction service valves are set correctly (OPEN).
Compressor Oil: The oil level in multiple scroll
compressors (piped in parallel) must be checked
immediately after all compressors are shut down and
have had time to stabilize.
JOHNSON CONTROLS
COMMISSIONING
The oil level must be between the bottom and middle of
the oil sight glass which is mounted in the oil equalizing
line between the compressors.
Fans: Check that all fans are free to rotate and are not
damaged. Ensure blades are at the same height when
rotated. Ensure fan guard is securely fixed.
Isolation/protection: Verify that all sources of electrical
supply to the unit are taken from a point of isolation.
Control Panel: Check the panel to see that it is free
of foreign materials (wire, metal chips, and so on) and
clean out if required.
Power Connections: Check that the customer power
cables are connected correctly. Ensure that connections
of power cables within the power panel to the non-fused
switch disconnects are tight.
Earthing: Verify that the unit earth terminal is properly
connected to a suitable earthing point. Ensure that all
unit internal earth connections are tight.
Supply Voltage: Verify that the site voltage supply
corresponds to the unit requirement and is within the
limits given in the Technical Data Section. The phase
imbalance should less than 2% of the average voltage.
Switch Settings: Ensure that the unit On/Off toggle
switch beneath the key pad in the electronic section
of the control panel is set to OFF. Set the non-fused
disconnect switch to ON. The customers disconnection
devices can now be set to ON.
Crankcase Heaters: Verify the heaters are energized.
Water System: Verify that the liquid system has been
installed correctly, and has been commissioned with
the correct direction of water flow through the heat
exchanger. Inlet should be at the refrigerant pipework
connection end of the heat exchanger. Purge air from
the heat exchanger using the air vent mounted in the
pipework.
ISSUE DATE: 10/15/2020
The machine is now live!
Depending upon the ambient temperature
the crankcase heaters must be on for 12 to
24 hours before start-up.
FORM 150.68-ICOM1
27
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