5
When the unit is subjected to fire, safety devices prevent rupture
due to over-pressure by releasing refrigerant. The fluid may
then be decomposed into toxic residues when subjected to the
flame:
•
Stay away from the unit
•
Set up warnings and recommendations for personnel in
charge to stop the fire.
•
Fire extinguishers appropriate to the system and the
refrigerant type must be easily accessible.
The external relief valves must in principle be connected to
discharge pipes for units installed in a room. Refer to the
installation regulations, for example those of European standards
EN 378 and EN 13136.
They include a sizing method and examples for configuration
and calculation. Under certain conditions these standards permit
connection of several valves to the same discharge pipe. Note:
Like all other standards these EN standards are available from
national standards organisations.
These pipes must be installed in a way that ensures that people
and property are not exposed to refrigerant leaks. These fluids
may be diffused in the air, but far away from any building air
intake, or they must be discharged in a quantity that is appropriate
for a suitably absorbing environment.
It is recommended to install an indicating device to show if part
of the refrigerant has leaked from the valve. The presence of oil
at the outlet orifice is a useful indicator that refrigerant has
leaked. Keep this orifice clean to ensure that any leaks are obvious.
The calibration of a valve that has leaked is generally lower
than its original calibration. The new calibration may affect the
operating range. To avoid a nuisance tripping or leaks, replace
or re-calibrate the valve.
Periodic check of the relief valves: See paragraph 1.3
“Maintenance safety considerations”.
Provide a drain in the discharge circuit, close to each relief
valve, to avoid an accumulation of condensate or rain water.
Ensure good ventilation, as accumulation of refrigerant in an
enclosed space can displace oxygen and cause asphyxiation or
explosions.
Inhalation of high concentrations of vapour is harmful and
may cause heart irregularities, unconsciousness, or death.
Vapour is heavier than air and reduces the amount of oxygen
available for breathing. These products cause eye and skin
irritation. Decomposition products are hazardous.
1.2 - Equipment and components under pressure
The units are intended to be stored and operate in an environment
where the ambient temperature must not be less than the lowest
allowable temperature indicated on the nameplate. See section
“10.2 - Pressure vessels”.
1.3 - Maintenance safety considerations
Carrier recommends the following drafting for a logbook (the
table below should not be considered as reference and does not
involve Carrier responsibility):
Intervention
Name of the
commissioning
engineer
Applicable
national
regulations
Verification
Organism
Date
Nature
(1)
(1) Maintenance, repairs, regular verifications (EN 378), leakage, etc.
Engineers working on the electric or refrigeration components
must be authorized, trained and fully qualified to do so.
All refrigerant circuit repairs must be carried out by a trained
person, fully qualified to work on these units. He must have been
trained and be familiar with the equipment and the installation.
All welding operations must be carried out by qualified specialists.
The insulation must be removed and heat generation must be
limited by using a wet cloth.
Any manipulation (opening or closing) of a shut-off valve must
be carried out by a qualified and authorised engineer. These
procedures must be carried out with the unit shut-down.
NOTE: The unit must never be left shut down with the liquid
line valve closed, as liquid refrigerant can be trapped between
this valve and the expansion device. (This valve is situated on
the liquid line before the filter drier box.)
During any handling, maintenance and service operations the
engineers working on the unit must be equipped with safety
gloves, glasses, shoes and protective clothing.
Never work on a unit that is still energized.
Never work on any of the electrical components, until the general
power supply to the unit has been cut using the disconnect
switch(es) in the control box(es).
If any maintenance operations are carried out on the unit, lock
the power supply circuit in the open position ahead of the
machine.
If the work is interrupted, always ensure that all circuits are
still deenergized before resuming the work.
ATTENTION: Even if the unit has been switched off, the power
circuit remains energized, unless the unit or circuit disconnect
switch is open. Refer to the wiring diagram for further details.
Attach appropriate safety labels.
Operating checks:
IMPORTANT INFORMATION REGARDING THE
REFRIGERANT USED:
•
This product contains fluorinated greenhouse gas covered
by the Kyoto protocol.
Fluid type: R134a
Global Warming Potential (GWP): 1430
Summary of Contents for 30HXC Series
Page 49: ......
