28
JOHNSON CONTROLS
FORM 150.68-ICOM1
ISSUE DATE: 10/15/2020
Flow rates and pressure drops must be
within the limits given in the Technical Data
Section. Operation outside of these limits
is undesirable and could cause damage.
Flow Switch: Verify a chilled liquid ow switch is
correctly tted in the customer’s pipework on the heat
exchanger outlet, and wired into the control panel
correctly.
Temperature Sensor(s): Ensure the leaving (-BLCT)
liquid temperature sensor is coated with heat conductive
compound (Part No. 013-00989-000) and are inserted
in the water outlet sensor pocket of the heat exchanger.
Control Supply: Verify the control panel display is
illuminated.
HP Cut-Out Reset: Check that the hand reset mechanical
high pressure cut-outs mounted on the discharge lines
are at the correct setting and are reset.
Programmed Options: Verify that the options factory
programmed into the Microprocessor Control Center are
in accordance with the customers order requirements by
pressing the ‘OPTIONS’ key on the keypad and reading
the settings from the display. Refer also to the IPUII
Service Manual for additional information.
Programmed Settings: Ensure the system cut-out and
operational settings are in accordance with operational
requirements by pressing the ‘PROGRAM’ key (refer
to Operation Section).
Date & Time: Press the ‘CLOCK’ key and set the date
and time (refer to Operation Section).
Start/Stop Schedule: Programme the daily and holiday
start/stop by pressing the ‘SCHEDULE/ADVANCE
DAY’ key (refer to Operation Section).
Setpoints: Set the required leaving chilled and hot
liquid temperature set-point and control range using the
‘SETPOINTS’ key (refer to Operation Section).
Mode Selection: Ensure under the ‘OPTIONS’ key that
LOCAL REMOTE MODE is set to LOCAL and that
CONTROL MODE is set to COOLING.
Compressor Operation: Use the ‘OPTIONS’ key
to switch o each refrigerant system in turn (refer to
Operating Instructions Manual) and then check the
compressors on the active system:
Connect a manifold gauge to each refrigerant circuit
suction and discharge service valves. Temporarily start
each compressor, and check that the discharge pressure
rises and the suction pressure decreases to ensure that the
compressors are operating in the correct rotation. Any
faults found must be corrected before starting the unit.
After completing the checks on both circuits, set both
systems to ON using the ‘OPTIONS’ key.
FIRST TIME START-UP
During the commissioning period there
should be sucient heat load to run the
unit under stable full load operation to
enable the unit controls, and system
operation to be set up correctly, and a
commissioning log taken.
Read the following section in conjunction with the IPUII
Service Manual, then proceed step by step as follows:
Interlocks: Verify that liquid is owing through the heat
exchanger and that heat load is present. Ensure that any
remote run interlocks are in the run position and that the
run schedule requires the unit to run or is overridden.
Start-up: Set the unit switch to the ON position to start
the unit (there may be a few seconds delay before the
rst compressor starts because of the anti-recycle timer).
Be ready when each compressor starts, to switch the unit
o immediately if any unusual noises or other adverse
conditions develop. Refer to the Technical Data Section
for the normal operating sequence from start-up.
Refrigerant Flow: When a compressor starts a ow
of liquid refrigerant will be seen in the liquid line sight
glass. After several minutes operation, and providing a
full charge of refrigerant is in the system, the bubbles
will disappear and be replaced by a solid column of
liquid. Check that the moisture indicator is satisfactory
(should appear Green).
System Operation: Use the ‘OPER DATA’ key to check
the system pressures and temperatures.
To Next Page
Loading...
Need help?
General
