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Instructions for Repairing Appliances Containing R290
1
General Instructions
1.1 Checks to the area
Prior to beginning work on systems containing flammable refrigerants,
safety checks are necessary to ensure that the risk of ignition is mini-
mised. For repair to the refrigerating system, the following precautions
shall be complied with prior to conducting work on the system.
1.2 Work procedure
Work shall be undertaken under a controlled procedure so as to minimise
the risk of a flammable gas or vapour being present while the work is
being performed.
1.3 General work area
All maintenance staff and others working in the local area shall be in-
structed on the nature of work being carried out. Work in confined spaces
shall be avoided. The area around the workspace shall be sectioned off.
Ensure that the conditions within the area have been made safe by control
of flammable material.
1.4 Checking for presence of refrigerant
The area shall be checked with an appropriate refrigerant detector prior to
and during work, to ensure the technician is aware of potentially flamma-
ble atmospheres. Ensure that the leak detection equipment being used is
suitable for use with flammable refrigerants, i.e. non-sparking, adequately
sealed or intrinsically safe.
1.5 Presence of fire extinguisher
If any hot work is to be conducted on the refrigeration equipment or
any associated parts, appropriate fire extinguishing equipment shall be
available to hand. Have a dry powder or CO2 fire extinguisher adjacent to
the charging area.
1.6 No ignition sources
No person carrying out work in relation to a refrigeration system which
involves exposing any pipe work that contains or has contained flammable
refrigerant shall use any sources of ignition in such a manner that it may
lead to the risk of fire or explosion. All possible ignition sources, including
cigarette smoking, should be kept sufficiently far away from the site of
installation, repairing, removing and disposal, during which flammable
refrigerant can possibly be released to the surrounding space. Prior to
work taking place, the area around the equipment is to be surveyed to
make sure that there are no flammable hazards or ignition risks. "No
Smoking" signs shall be displayed.
1.7 Ventilated area
Ensure that the area is in the open or that it is adequately ventilated
before breaking into the system or conducting any hot work. A degree of
ventilation shall continue during the period that the work is carried out.
The ventilation should safely disperse any released refrigerant and prefer-
ably expel it externally into the atmosphere.
1.8 Checks to the refrigeration equipment
Where electrical components are being changed, they shall be fit for the
purpose and to the correct specification. At all times the manufacturer's
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 flammable refrigerants: the
charge size is in accordance with the room size within which the refrig-
erant 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 pres-
ence of refrigerant; marking to the equipment continues to be visible and
legible. Markings and signs that are illegible shall be corrected; refrigera-
6
CL3672_Service-Anleitung
tion 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.
1.9 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 tem-
porary 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 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
2.1 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.
2.2 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 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.
CAUTION:
The use of silicon sealant may inhibit the effectiveness of some
types of leak detection equipment. Intrinsically safe components do
not have to be isolated prior to working on them.
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 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.
4
Cabling
Check that cabling will not be subject to wear, corrosion, excessive pres-
sure, 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 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.
20.12.2017
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