8
Even if the unit has been shut down, the power circuit
remains energized, as long as the unit or circuit disconnect
switch is not open. Refer to the wiring diagram for further
details. Follow the appropriate safety guidelines. When
working in a fan area, specifically if the grilles have to be
removed, isolate the power supply to the fans to prevent
their operation.
Units equipped with the variable speed fan option, variable
speed pump options and the power factor option are equipped
with capacitor batteries which take 5 minutes to fully discharge
once the power has been switched off.
After disconnecting the power supply to the electrics box, wait
5 minutes before accessing the electrics box or variable drives.
Before any intervention, verify that there is no voltage present
at any accessible conducting parts of the power circuit.
Ensure regularly that the vibration levels remain acceptable
and close to those at the initial unit start-up.
Before opening a refrigerating circuit, purge and read the
pressure indicators.
If the refrigerant circuit remains open after an intervention
(such as a component replacement, etc.):
•
Seal the openings if the duration is less than a day
•
Beyond this time, charge the circuit with a dry, inert gas
(nitrogen).
The objective is to prevent penetration of atmospheric
humidity and the resulting corrosion of the unprotected
internal steel walls.
1.5 - Repair safety considerations
To prevent any damage or accidents, trained personnel must
service the various parts of this unit and must resolve any
malfunctions or leaks immediately.
Comply with the regulations and recommendations given in
the safety standards for refrigerating systems and machines,
such as: EN 378, ISO 5149, etc.
Risk of explosion:
Never use air or gases containing oxygen during leak tests, to
purge ducts or to pressurise a unit. Pressurised air mixtures or
gases containing oxygen can be the cause of an explosion.
Oxygen reacts violently with oil and grease.
Only use dry nitrogen for leak tests, possibly with an
appropriate tracer gas.
A failure to observe the above recommendations can have
serious or even fatal consequences and damage the
installations.
Never exceed the specified maximum operating pressures.
Verify the maximum permissible high and low test pressures
by checking the instructions in this manual or the pressures
given on the unit name plate.
The necessary protection equipment must be available, and
appropriate fire extinguishers for the system and the
refrigerant type used must be within easy reach.
Do not attempt to remove refrigerant circuit components or
fittings while the machine is under pressure or while it is
running. Make sure the circuit pressure is zero and that the
unit has been shut down and de-energised before removing
components or opening a circuit. When the refrigerant circuit
is opened to repair, see the blanketing recommendations in
the "Maintenance safety considerations" paragraph.
No part of the unit must be used as a walkway, rack or support.
Periodically check and repair or, if necessary, replace any
component or piping that shows signs of damage.
The lines can break under the weight and release refrigerant,
causing personal injury.
Do not climb on a machine. Use a platform to work at height.
Use mechanical lifting equipment (crane, hoist, winch, etc.) to
lift or move heavy components.
For lighter components, use lifting equipment if there is any
risk of slipping or losing your balance.
Use only original spare parts for any repair or component
replacement. Consult the list of spare parts that corresponds
to the original equipment.
Do not drain treated and/or added fluid from the heat-transfer
circuit (e.g. antifreeze) without informing the site technical/
service department or other competent body first.
Close the shut-off valves on the water inlet and outlet and
drain the unit's hydraulic circuit before working on the
components installed on the circuit (screen filter, pump, water
flow sensor, etc.).
Periodically inspect all valves, couplings and pipes on the
refrigerating and hydraulic circuits to ensure that they do not
show any signs of corrosion or leaks.
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