A5P | 01
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 minimized for repair
to the refrigerating system, the following precautions
shall be complied with prior to conducting work on
the system.
Work procedure
Work shall be undertaken under a controlled
procedure so as to minimize the risk of a flammable
gas or vapour being present while the work is being
performed.
2.General work area
All maintenance staff and others working in the local
area shall be instructed 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.
3.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 flammable
atmospheres. Ensure that the leak detection
equipment being used is suitable for use with
flammable refrigerant, i.e. non sparking, adequately
sealed or intrinsically safe.
4.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.
5.No ignition sources
No person carrying out work in relation to a refrigerant
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.
6.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 wok. A degree of ventilation
shall continue during the period that the work is
carried out. The ventilation should safely disperse any
released refrigerant and preferably expel it externally
into the atmosphere.
7.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 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
8.Checks to electrical devices
Repair and maintenance to electrical components shall
include initial safety checks and components 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 there no live electrical components and wiring are
exposed while charging, recovering or purging the system;
-that there is continuity of earth bonding
9.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 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 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.
NOTE: 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.
10.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 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
manufacturer. Other parts may result in the ignition of
refrigerant in the atmosphere from a leak.
11.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.
12.Leakage detection for 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.
MAINTENANCE
