Checking For Leakage; Fire Security; Risk Of Flame; Area Ventilation - Bosch CLIMATE 5000 Service Manual

Safety Instructions
1.2.4

Checking for leakage

The area shall be checked with an appropriate refrigerant detector
before and also during the work in case of need.
The leakage detector must be suitable for using with flammable
refrigerants, i.e. no sparking, adequately sealed or intrinsically safe.
1.2.5

Fire security

If any hot work is to be conducted on the refrigeration equipment or
any associated parts, appropriate fire extinguishing equipment shall be
available in working area.
1.2.6

Risk of flame

During working on refrigeration system with category 2L, any kind of
flame source must be avoided to exclude risk of fire or explosion.
Smoking is stritcly forbidden during installation, commissioning and
repair works. A "NO SMOKING" warning sign should be visible on side.
1.2.7

Area ventilation

Before starting any hot work in the system, it must be ensured that the
area has a sufficient and continuous ventilation. If a fan will be used for
this purpose, it must be an ex-proof type.
1.2.8

Installation check

Electrical components must have the correct specifications which are
included in the product maintenance and service guidelines. In case of
need, please contact your local service department.
Following checks should be made at installations with refrigerants of
category 2L:
• Refrigerant charging amount must be proper to the room size.
• Inlets and outlets for ventilation must be free of obstacles.
• 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.
• All warning signs must be visible and legible.
• Refrigeration pipes or refrigerant containing components must be
installed in areas which are protected against corrosion.
1.2.9

Electrical work

Electrical work must only be carried out by electrical installation
contractors. Before starting electrical work:
• Isolate all poles of the mains voltage and secure against reconnec-
tion.
• Make sure the mains voltage is disconnected and has no open wiring
during charging, recovering and purging of the system.
• The electrical grounding must exist continuously.

1.2.10 Repair of 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 the measuring device 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 flam-
4
mable atmospheres. Replacement parts shall be in accordance with
the manufacturer's specifications.
NOTICE:
The use of silicon sealant may inhibit the effectiveness of some types
of leak detection equipment. Therefore, intrinsically safe components
should not be isolated before working on them.

1.2.11 Repair of intrinsically safe components

Do not apply any permanent inductive or capacitance loads to the
circuit without ensuring that this will not exceed the allowed voltage
and current for the equipment in use. Intrinsically safe components are
the only types that can be worked on in presence of flammable gas. The
measuring device shall be at the correct rating.
Replace components only with parts specified by the manufacturer.
Other parts may result a damage in case of leakage.

1.2.12 Wiring

Check that cables are not damaged by corrosion, excessive pressure,
vibration, sharp edges or any other adverse environmental effects. The
effects of aging or continual vibration from sources such as compressors
or fans should be considered also.

1.2.13 Detection of flammable refrigerants

Never use open flame for leakage test!

1.2.14 Leak detection methods

The following leak detection methods are 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 cause corrosion of the copper pipe-work.
• If a leak is suspected, all open flame sources shall be removed or
extinguished.
• If a leakage of refrigerant is detected which requires brazing, all of
the refrigerant shall be recovered from the system or isolated partly
with the help of existing valves. Oxygen free nitrogen (OFN) should
be purged through the system both before and during the brazing
process.

1.2.15 Removal and evacuation

For any kind of repair work on the refrigerant circuit pipes, following
procedure should be considered:
• remove refrigerant;
• purge the circuit with inert gas;
• evacuate;
• purge again with inert gas;
• open the circuit by cutting or brazing.
The refrigerant charge shall be recovered into the correct recovery
cylinders. The system shall be flushed with OFN to render the unit safe.
This process may need to be repeated several times. Compressed air
or oxygen shall not be used for this task. Flushing shall be achieved by
breaking the vacuum in the system with OFN and continuing to fill until
the working pressure is achieved, then venting to atmosphere, and
finally pulling down to a vacuum. This process shall be repeated until no
CLIMATE 5000 RAC SINGLE SPLIT (R32) – 6720894076 (2019/08)