12
ammable atmospheres. Ensure that the leak det
used is suitable for use with all applicable refrigerants, i.e
adequately sealed or intrinsically safe.
Presence of re e
If any hot work is to be conducted on the refrigeration equipment or
any associated parts, appropriate re extinguishing equipment shall be
available to hand. Hav
the charging area.
No ignition sources
No person carrying out work in relation to a refrigeration system which
involves exposing an
manner that it may lead to the risk of re or explosion.
All possible ignition sources, including cigar
suciently far away from the site of installa
and disposal, during which refrigerant can possibly be released to the
surrounding space. Prior t
equipment is to be surveyed to make sure that there ar
hazards or ignition risks. "No Smoking" signs shall be displayed.
V
Ensure that the area is in the open or that it is adequately v
before breaking into the system or c
of ventilation shall continue during the period that the work is carried
out.
preferably expel it externally into the atmospher
Checks to the refrigeration equipment
Where electrical components are being changed, they shall be t for the
purpose and to the correct specication. At all times the manufacturer’
maintenance and service guidelines shall be followed.
If in doubt, consult the manufacturer's technical department for assistance.
The following checks shall be applied to installations using ammable
refrigerants:
• The actual refrigerant charge is in accordanc
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 refrigeran
• 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 substanc
refrigerant containing components
constructed of materials which are inherently resistan
corroded or are suitably protected against being so corr
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
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. T
equipment so all parties are advised.
Initial safety checks shall include:
• That capacitors are discharged: this shall be done in a saf
avoid possibility of sparking;
• That no live electrical components and wiring are exposed while
charging, rec
• That there is continuity of earth bonding.
Repairs to sealed components
During repairs to sealed components, all electrical supplies shall be
disconnected from the equipment being worked upon prior to any
removal of sealed cov
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 follo
working on electrical components, the casing is not altered in such a
way that the level of prot
cables, excessiv
specication, damage to seals, incorrect tting of glands, etc
• Ensure that the apparatus is mounted secur
• Ensure that seals or sealing materials have not deg
that they no longer serve the purpose of preventing the ingress of
ammable atmospheres. Replacement parts shall be in accordance with
the manufacturer’s specica
NOTE:
The use of silicon sealant can inhibit the eectiveness of some types of
leak detection equipment. Intrinsically safe components do not have to be
isolated prior to working on them.
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
shall be at the correct rating.
Replace components only with parts specied by the manufacturer
parts may result in the ignition of refrigerant in the atmosphere from a
leak.
Cabling
Check that cabling will not be subject to wear
pressure, vibration, sharp edges or an
eects.
continual vibration from sourc
Detection of ammable refrigerants
Under no circumstances shall potential sourc
searching for or detection of refrigerant leaks
detector using a naked ame) shall not be used.
Leak detection methods
The following leak detection methods are deemed acc
refrigerant systems.
Electronic leak detectors may be used to detect refrigerant leaks but, in
the case of ammable refrigerants, the sensitivity may not be adequate
or may need re-calibration. (Detection equipment shall be calibrated in a
refrigerant-free area.) Ensur
ignition and is suitable for the refrigerant used
shall be set at a percentage of the LFL of the refrigerant and shall be
calibrated to the refrigerant emplo
gas (25 % maximum) is conrmed.
Leak detection uids are suitable for use with most refrigeran
use of detergents containing chlorine shall be av
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 recov
shut o valves) in a part of the system remote from the leak. F
containing ammable refrigerants, o
be purged through the system both bef
Removal and evacua
When breaking into the refrigerant circuit to make r
purpose – conventional proc
refrigerants it is important that best practice is followed since ammability
is a consideration.
• remove refrigeran
