Trane 5TXCA001AS3HCA Installer's Manual page 3

• The area shall be checked with an appropriate refrigerant
detector prior to and during work, to ensure the technician
is aware of potentially toxic or flammable atmospheres.
Ensure that the leak detection equipment being used is
suitable for use with all applicable refrigerants, i.e., non-
sparking, adequately sealed or intrinsically safe.
• If any hot work is to be conducted on the refrigerating
equipment or any associated parts, appropriate fire
extinguishing equipment shall be available to hand. Have a dry
powder or CO2 fire extinguisher adjacent to the charging area.
• No person carrying out work in relation to a refrigerating
system which involves exposing any pipe work shall use
any sources of ignition in such a manner that it may lead
to the risk of fire or explosion. All possible ignition sources,
including cigarette smoking, should be kept sufficiently far
away from the site of installation, repairing, removing and
disposal, during which refrigerant can possibly be released
to the surrounding space. Prior to work taking place, the
area around the equipment is to be surveyed to make sure
that there are no flammable hazards or ignition risks. "No
Smoking" signs shall be displayed.
• Ensure that the area is in the open or that it is adequately
ventilated before breaking into the system or conducting
any hot work. A degree of ventilation shall continue during
the period that the work is carried out. The ventilation
should safely disperse any released refrigerant and
preferably expel it externally into the atmosphere.
• The following checks shall be applied to installations
using flammable refrigerants:
– marking to the equipment continues to be visible and
legible. Markings and signs that are illegible shall be
corrected;
– refrigerating pipe or components are installed in a
position where they are unlikely to be exposed to
any substance which may corrode refrigerant
containing components, unless the components are
constructed of materials which are inherently
resistant to being corroded or are suitably protected
against being so corroded.
Repairs to Electrical Components
Where electrical components are being changed, they shall be
fit for the purpose and to the correct specification. At all times
the manufacturer's maintenance and service guidelines shall
be followed. If in doubt, consult the manufacturer's technical
department for assistance.
Repair and maintenance to electrical components shall include
initial safety checks and component inspection procedures. If
a fault exists that could compromise safety, then no electrical
supply shall be connected to the circuit until it is satisfactorily
dealt with. If the fault cannot be corrected immediately but it
is necessary to continue operation, an adequate temporary
solution shall be used. This shall be reported to the owner of
the equipment, so all parties are advised.
Initial safety checks shall include:
• that capacitors are discharged; this shall be done in a
safe manner to avoid possibility of sparking;
• that no live electrical components and wiring are exposed
while charging, recovering or purging the system;
18-AD47D1-1B-EN
Installer's Guide
• that there is continuity of earth bonding.
Check that cabling will not be subject to wear, corrosion,
excessive pressure, vibration, sharp edges or any other
adverse environmental effects. The check shall also take into
account the effects of aging or continual vibration from sources
such as compressors or fans.
Detection of Flammable Refrigerants
Under no circumstances shall potential sources of ignition be
used in the searching for or detection of refrigerant leaks. A
halide torch (or any other detector using a naked flame) shall
not be used.
The following leak detection methods are deemed acceptable
for all refrigerant systems:
• Electronic leak detectors may be used to detect refrigerant
leaks but, in the case of flammable refrigerants, the
sensitivity may not be adequate, or may need re-
calibration. (Detection equipment shall be calibrated
in a refrigerant-free area.) Ensure that the detector is
not a potential source of ignition and is suitable for the
refrigerant used. Leak detection equipment shall be set
at a percentage of the LFL of the refrigerant and shall be
calibrated to the refrigerant employed, and the appropriate
percentage of gas (25 % maximum) is confirmed.
• Leak detection fluids are also suitable for use with most
refrigerants but the use of detergents containing chlorine
shall be avoided as the chlorine may react with the
refrigerant and corrode the copper pipe-work.
Examples of leak detection fluids are:
• bubble method,
• fluorescent method agents
If a leak is suspected, all naked flames shall be removed/
extinguished.
If a leakage of refrigerant is found which requires brazing, all of the
refrigerant shall be recovered from the system, or isolated (by means
of shut off valves) in a part of the system remote from the leak.
Removal and Evacuation
When breaking into the refrigerant circuit to make repairs - or
for any other purpose - conventional procedures shall be used.
However, for flammable refrigerants it is important that best
practice be followed, since flammability is a consideration. The
following procedure shall be adhered to:
• safely remove refrigerant following local and national
regulations;
• evacuate;
• purge the circuit with inert gas (optional for A2L);
• evacuate (optional for A2L);
• continuously flush or purge with inert gas when using
flame to open circuit;
• and open the circuit.
The refrigerant charge shall be recovered into the correct
recovery cylinders if venting is not allowed by local and national
codes. For appliances containing flammable refrigerants, the
system shall be purged with oxygen-free nitrogen to render the
appliance safe for flammable refrigerants.
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