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8
IMPORTANT SAFETY INSTRUCTIONS
damage to cables, excessive number of
connections,
terminals
original specification, damage to seals,
incorrect fitting of glands, etc. Ensure
that apparatus is mounted securely.
Ensure that seals or sealing materials
have not degraded such that they no
longer serve the purpose of preventing
the ingress of flammable atmospheres.
Replacement parts shall be in accordance
with the manufacturer's specifications.
NOTE: The use of silicon sealant may inhibit
the effectiveness of some types of leak
detection
equipment.
components do not have to be isolated
prior to working on them.
8. Intrinsically safe components must be
replaced.
Do not apply any permanent inductive or
capacitance loads to the circuit without
ensuring that this will not exceed the
permissible
voltage
permitted for the equipment in use.
Intrinsically safe components are the only
types that can be worked on while live in
the presence of a flammable atmosphere.
The test apparatus shall be at the correct
rating. Replace components only with
parts specified by the manufacturer.
Other parts may result in the ignition of
refrigerant in the atmosphere from a leak.
9. Cabling
Check that cabling will not be subject to
wear,
corrosion,
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.
10.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
containing
flammable
Electronic leak detectors shall be used to
not
made
Intrinsically
safe
and
current
excessive
pressure,
for
systems
refrigerants.
detect flammable refrigerants, but the
to
sensitivity may not be adequate, or may
need
equipment
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
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. If a leak is suspected,
all
naked
removed/extinguished. If a leakage of
refrigerant
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
Removal of refrigerant shall be according
to Removal and evacuation.
11. 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
re-calibration.
shall
be
calibrated
flames
shall
is
found
which
remote
from
(Detection
in
a
be
requires
the
leak.
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