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The following checks shall be applied to
installations using flammable refrigerants:
–
The actual refrigerant charge is in
accordance with the room size within which
the refrigerant containing parts are installed;
–
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 perare
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 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;
–
That there is continuity of earth bonding.
R R e e p p a a i i r r s s t t o o s s e e a a l l e e d d c c o o m m p p o o n n e e n n t t s s
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.
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
PTAC-SVX004A-EN
T T r r o o u u b b l l e e s s h h o o o o t t i i n n g g a a n n d d R R e e s s o o u u r r c c e e s s
protection is affected. This shall include damage to
cables, excessive number of connections, terminals not
made to original specification, damage to seals,
incorrect fitting of glands, etc.
•
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
purpose of preventing the ingress of flammable
atmospheres. Replacement parts shall be in
accordance with the manufacturer's specifications
R R e e p p a a i i r r t t o o i i n n t t r r i i n n s s i i c c a a l l l l y y s s a a f f e e c c o o m m p p o o n n e e n n t t s s
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
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.
N N o o t t e e : : The use of silicon sealant can inhibit the
effectiveness of some types of leak detection
equipment. Intrinsically safe components do not
have to be isolated prior to working on them.
C C a a b b l l i i n n g g : :
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.
D D e e t t e e c c t t i i o o n n o o f f f f l l a a m m m m a a b b l l e e r r e e f f r r i i g g e e r r a a n n t t s s
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.
37
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