J&M CellarPlus 70-S1/S3, Technical Manual

Page: 13 / 32

Issue: 01.06.2023 Page 10
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Ensure that the power supply corresponds to the unit and
that the power supply is stable.
•
Connect power supply according to the present norm
and legal requirement. Ensure that the unit is properly
connected to the ground.
•
Access to the electrical terminals and components on the
indoor unit is via the removable cover plate on the front
of the unit. Removal of the cover plate gives access to
the contactor, the terminal block as well as the electronic
controller and rocker switch connections.
•
To gain access to the electrical box on the outdoor unit,
remove the screws of the panel located on the right-
hand side of the unit and remove the panel. The
electrical box is located behind the panel.
•
3phase scroll compressor: incoming live wires need
correctly terminated at condensing unit’s terminal
block for the compressor to rotate in correct direction
(compression).
•
The outdoor unit is equipped with an overload relay to
protect compressor from overheating. It was preset from
factory and never set value higher than set current on
wiring diagram.
Commissioning
To gain access to the electrical box on the indoor and
outdoor unit, isolate the power supply to the outdoor unit
and indoor unit by turning the remote motor rated circuit
breaker to the OFF position.
To access the electrical box on the outdoor unit: Loosen the
screws from the right-side panel.
To access electrical box on the indoor unit: Loosen the
screws from the L shaped window panel.
Pre startup checks
Before starting the system, the following checks should be
carried out as a minimum:
•
Check electrical supply is correct and all connections
are sound.
•
All moving parts are free, and guards are fitted.
•
Compressor oil level satisfactory.
•
Initial settings for safety switches.
•
Overload set correctly.
•
All valves are in correct operating position.
•
Initial refrigerant charge.
•
Gauge manifold connected to both low and high sides
of system.
Before starting the system, ensure that all
electrical connections are correctly made and
tight, service ports are in the correct position
and all covers and guards are fitted.
Unit startup
•
Switch on the power of the main isolator and then
switch on the rocker switch on the front of the indoor
unit.
•
Set the required room temperature on the electronic
controller (Lead controller on Twin Systems) and check
the system parameters in the controller as required (the
controllers are pre-programmed in the factory to the
suggested settings).
•
Run the system to the required temperature and check
system pressures and temperatures, gas charge and
running currents of motors to ensure correct operation.
•
Check compressor suction superheat. This should be
between 10~20K at normal operating conditions.
•
Final adjustment of safety switch settings.
•
Allow the system to run for 3 – 4 hours. Check
compressor oil level and top up with the correct oil type
as required (RL32-3MAF). Recheck the compressor oil
level again after 24 hours operation.
•
Carry out final leak test and ensure all panels/covers
are fitted and screws tightened.
•
Log all information along with the system model and
serial numbers for future reference.
•
Ensure that the customer / responsible person is
provided with basic operating instructions and where
electrical isolators are situated in case of emergency.
An anti-short cycle timer is built into the
indoor controller to prevent the compressor
from stop/starting too quickly, which can
result in the compressor tripping on its
internal overload. If the overload trips,
please allow time for it to cool down and auto reset
before restarting.
Compressor Operation
Scroll compressor motors are designed to run only in one
direction.
This is not an issue with single phase compressors as
they will always run in the correct direction. The correct
rotation of a three-phase compressor motor depends on the
connection of the three incoming phases to the unit. Correct
rotation can be determined by a drop in suction pressure and
a rise in discharge pressure when the compressor is
energized. Running the compressor for a short period of time
in reverse direction will have no negative impact but
prolonged running in reverse direction may cause premature
failure.
To reverse the rotation of a three-phase scroll
compressor, shut off the incoming power supply to the unit,
swap connection of any two of the three incoming phases at the
unit
’s terminal block , reapply power to the unit and following
compressor restart, recheck operating pressures.
The condensing unit does not include phase protector. Thus,
it is necessary to ensure correct scroll compressor rotation
and incoming line voltage variance /-2% during
commissioning.
•
3 phase scroll compressors require proper phase
sequence to secure right rotation and therefore
compression.
•
Do not use a megohmmeter nor apply power to the
compressor while the system under vacuum as this
may cause internal damage to the compressor.
•
Never start the compressor under vacuum (do not
operate the compressor with the low-pressure cut-out
bypassing), as
this will cause the rotating part to
overheat very quickly causing premature failure.