Oasis I19 Installation Instructions Manual Download Page 30

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Repairs to sealed components
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
isabsolutely 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) 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

5. MAINTENANCE AND INSPECTION

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.

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.

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.

Leak detection methods
The following leak detection methods are deemed acceptable for systems containing
flammable refrigerants.
Electronic leak detectors shall be used to detect flammable refrigerants, but 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 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.
If a leak is suspected, all naked flames shall be removed/ extinguished.
If a leakage of refrigerant is found which requires brazing, all of the refrigerant shall be
recovered from the system, or isolated (by means of shut off valves) 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.

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.

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 preferably expel it externally into the atmosphere. prolonged period of no
usage.

5. MAINTENANCE AND INSPECTION

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 minimised. For repair to the refrigerating
system, the following precautions shall be complied with prior to conducting work on the
system. prolonged period of no usage.

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 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 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 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.