Pressure Testing; Evacuation And Charging; Electrical - J&E Hall V3 FUSION Technical Manual

Installation

Pressure Testing

Never use oxygen, dry air, or acetylene for
pressure testing of the system as these may
form an inflammable mixture.
•
The condensing units are pressure tested in the factory
prior to dispatch. All units come with a holding charge
of oxygen free nitrogen ~2barg. Remove the holding
charge indication tag which is tied to service valve
before installation.
•
Once the pipework installation is complete, it should be
pressure tested for leak prior to evacuation.
•
A pressure leak test should be carried out using
oxygen free nitrogen (OFN). A calibrated nitrogen
pressure regulator must always be used. Before
starting any pressure testing, ensure the area
surrounding the system is safe, inform relevant
personnel and fit warning signs indicating high pressure
testing. Also, use correct PPE as required.
•
Always pressurize the system slowly, preferably in
stages up to the maximum required pressure. Never
exceed maximum working pressures shown in below
table. Failure to obey the limit will cause premature
failure on the pressure safety device.
Table 3: Maximum working pressure
High Side, barg (psig)
28 (405)
•
Listen for any possible leaks and check all joints with
bubble spray. If any leaks are discovered, release
pressure slowly from both suction and liquid line of
system until empty, repair leak and then repeat
pressure testing procedure. Never attempt to repair a
leak on a pressurized system.
•
A strength test should also be incorporated (to the
installed pipework only) according to applicable
standards.
•
Once testing has been completed satisfactorily, release
the pressure from the system gradually and safely to
external atmosphere.

Evacuation and Charging

Moisture prevents proper functioning of the
compressor and the refrigeration system.
Ensure that a good quality vacuum pump is
used to pull a minimum vacuum of 250
microns (0.25 torr) measured at refrigeration system, and
not at the vacuum pump gauge.
Once pressure testing has been completed, the system
needs to be evacuated to remove any moisture from the
piping. This can be done as follows:
•
Ensure any nitrogen charge is safely released from the
system.
•
Connect a gauge manifold to the connections on the
service valves on the condensing unit.
•
Connect a vacuum pump and vacuum gauge to the
system.
•
Ensure all gauge manifold and service valves in open
position.
•
Evacuate the system until vacuum is below 250 microns
(0.25 torr).
Issue: 01.06.2023
Low Side, barg (psig)
19 (275)
Note: A triple evacuation procedure is recommended for
all new systems or where moisture is suspected.
•
Once the system is isolated and the vacuum pump is
switched off, any rise in pressure indicates that either
there may be a leak in the system or moisture is still
present. In this case, recheck the system for leaks,
repair as necessary, and then repeat the evacuation
procedure.
•
Once evacuation is completed satisfactorily, the
vacuum pump and vacuum gauge can be removed. At
this point, the refrigerant charge can be added to the
system as required. Refrigerant blend must be charged
in liquid form to avoid change of chemical properties.
•
Ensure an adequate liquid charge (4~5barg) has been
introduced to the high side of the system before
starting the compressor.
•
The remaining charge is slowly throttled into suction
side until the installation has reached a level of stable
nominal condition during operation. Charging liquid
into the suction side of the system should ONLY be
done with a metering device. Ensure a minimum
operating pressure 0.5 barg is maintained when
adding refrigerant to the suction side, otherwise
overheating of the compressor may occur. Use
calibrated weighing scales to record the amount of
refrigerant added to the system.
•
Stop the filling once obtain sufficient suction superheat
and liquid subcooling, remove the cylinder from circuit.
Refrigerant charge by judging the liquid
sight glass does not guarantee as 100%
correct way.

Electrical

The mains electrical supply to the condensing
unit must be via a suitable motor rated circuit
breaker or fuse. A mains isolator is fitted to
all condensing units. Therefore, an additional
isolator is not required unless site conditions
or regulations dictate differently.
J & E Hall Fusion & Fusion Scroll condensing units require
power supply single or three phase which include Neutral
and an Earth. These systems are not suitable for any other
supply voltages (other than specified in Table 2).
•
Mains supply cable type and size must be selected to
suit the application and the electrical installation should
conform to the current local standards.
•
Cables to the condensing unit should, wherever
possible, be routed through the cable glands supplied
on the rear of the units.
•
Connect the mains supply to the units as per the wiring
diagrams.
•
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.
•
3phase scroll compressor: live wires need correctly
terminated at motor rated circuit breaker for the
compressor to rotate in correct direction (compression).
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