159
Installation
- The ventilation machinery and outlets are operating
adequately and are not obstructed.
- If an indirect refrigerating circuit is being used, the
secondary circuit shall be checked for the presence
of refrigerant.
- Marking to the equipment continues to be visible
and legible. Markings and signs that are illegible
shall be corrected.
- Refrigeration 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.
Checks to electrical devices
- 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 that all
parties are advised.
- Initial safety checks shall include:
(1) that capacitors are discharged: this shall be done in
a safe manner to avoid possibility of sparking;
(2) that no live electrical components and wiring are
exposed while charging, recovering or purging the
system;
(3) that there is continuity of earth bonding.
Repairs to sealed components
- During repairs to sealed components, all electrical
supplies shall be disconnected 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.
- Ensure that by working on electrical components,
the casing is not altered in such a way that the
cables, excessive number of connections, terminals
- Ensure that the apparatus is mounted securely.
- Ensure that seals or sealing materials have not
degraded to the point that they no longer serve the
atmospheres. Replacement parts shall be in
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
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manufacturer. Other parts may result in the ignition
of refrigerant in the atmosphere from a leak.
Cabling
- Check that cabling will not be subject to wear,
corrosion, excessive pressure, vibration, sharp
of aging or continual vibration from sources such as
compressors or fans.
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
Leak detection methods
- Electronic leak detectors may be used to detect
refrigerant leaks but the sensitivity may not be
adequate, or may need re-calibration for the
- 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
- The use of detergents containing chlorine shall be
avoided.
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removed/extinguished.
- If a leakage of refrigerant is found which requires
brazing, all of the refrigerant shall be recovered from
in a part of the system remote from the leak. Oxygen
free nitrogen (OFN) shall then be purged through
the system both before and during the brazing
process.
Removal and evacuation
- The refrigerant charge shall be recovered into the
correct recovery cylinders and the system shall be
process may need to be repeated several times.
- Compressed air or oxygen shall not be used for
purging refrigerant systems.
- Flushing shall be achieved by breaking the vacuum
the working pressure is achieved, then venting
vacuum. This process shall be repeated until no
charge is used, the system shall be vented down
to atmospheric pressure to enable work to take
place. This operation is absolutely vital if brazing
operations on the pipework are to take place.
- The outlet for the vacuum pump is not close to any
ignition sources and that ventilation is available.
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