Mistral MA02016KRY30 - Safety Checks and Repairs; Component Repair and Leak Detection

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Initial safety checks shall include:
• That capacitors are discharged: this shall be
done in a safe manner to avoid possibility of
sparking;
• That there no live electrical components
and wiring are exposed while charging,
recovering or purging the system;
• That there is continuity of earth bonding.
2. Repairs to sealed components
1. During repairs to sealed components, all
electrical supplies shall be disconnected
from the equipment being worked upon prior
to any removal of sealed covers, etc. If it is
absolutely necessary to have an electrical
supply to equipment during servicing, then
a permanently operating form of leak
detection shall be located at the most critical
point to warn of a potentially hazardous
situation.
2. Particular attention shall be paid to the
following to ensure that by working on
electrical components, the casing is not
altered in such a way that the level of
protection is affected. This shall include
damage to cables, excessive number of
connections, terminals not made to original
specication, damage to seals, incorrect
tting 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
ammable atmospheres. Replacement parts
shall be in accordance with the manufacturer’s
specications.
3. Repair to intrinsically safe
components
Do not apply any permanent inductive or
capacitance loads to the circuit without ensuring
that this will not exceed the permissible voltage
and current 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 ammable atmosphere. The test apparatus
shall be at the correct rating.
Replace components only with parts specied
by the manufacturer. Other parts may result in
the ignition of refrigerant in the atmosphere from
a leak.
4. Cabling
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.
5. Detection of ammable 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 ame) shall not be used.
The following leak detection methods are
deemed acceptable for systems containing
ammable refrigerants.
Electronic leak detectors shall be used to detect
ammable refrigerants, but 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 conrmed.
Leak detection uids 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 ames 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.