Bosch Climate 5000 SCI Installation Manual page 25

• Marking and signs that are illegible must 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.
9. Checks of electrical devices
Repair and maintenance of electrical components must include initial
safety checks and component inspection procedures. If a fault exists that
could compromise safety, then no electrical supply must 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 must be used. This must be reported to
the owner of the equipment so all parties are advised.
Initial safety checks include:
• Capacitors are discharged: this shall be done in a safe manner to
avoid possibility of sparking
• No live electrical components and wiring are exposed while
charging, recovering or purging the system;
• There is continuity of earth bonding.
10. Repairs to sealed components
10.1 During repairs to sealed components, all electrical supplies must
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 must be located at
the most critical point to warn of a potentially hazardous situation.
10.2 Particular attention must be paid to the following to ensure that
during work 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 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.
11. 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. Intrinscially safe
components are the only types that can be worked on while live in the
presence of a flammable atmosphere. The test apparatus must 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.
12. Cabling
Check that cabling will not be subject to wear, corrosion, excessive
pressure, vibration, sharp edges or any other adverse environmental
effects. The check must also take into account the effects of aging or
continual vibration from sources such as compressors or fans.
Climate 5000 SCI – 6720887405 (2018/04)
13. Detection of flammable refrigerants
Under no circumstances may potential sources of ignition be used in
searching for or detection of refrigerant leaks. A halide torch (or any
other detector using a naked flame) must not be used.
14. Leak detection methods
The following leak detection methods are deemed acceptable for
systems containing flammable refrigerants. Electronic leak detectors
must be used to detect flammable refrigerants, but the sensitivity may
not be adequate or may need re-calibration. (Detection equipment
must be calibrated in a refrigerant-free area.) Ensure that the detector
is not a potential source of ignition and is suitable for the refrigerant.
Leak detection equipment must be set at a percentage of the LFL of the
refrigerant and must be calibrated to the refrigerant employed, and the
appropriate percentage of gas (25% maximum) must be confirmed.
Leak detection fluids are suitable for use with most refrigerants, but the
use of detergents containing chlorine must be avoided as the chlorine
may react with the refrigerant and corrode the copper pipework.
If a leak is suspected, all naked flames must be removed or extinguished.
If a leakage of refrigerant is found which requires brazing, all of the
refrigerant must 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) must then be purged through the system both before
and during the brazing process.
15. Removal and evacuation
When breaking into the refrigerant circuit to make repairs for any
purpose conventional procedures must be used. However, it is important
that best practice is followed since flammability is a consideration. The
following procedure must be adhered to:
• Remove refrigerant.
• Purge the circuit with inert gas.
• Evacuate.
• Purge again with inert gas.
• Open the circuit by cutting or brazing.
The refrigerant charge must be recovered into the correct recovery
cylinders. The system must be flushed with OFN to render the unit safe.
This process may need to be repeated several times. Compressed air or
oxygen must not be used for this task.
Flushing must 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 must be repeated until no refrigerant is within the system.
When the final OFN charge is used, the system shall be vented down to
atmospheric pressure to enable work to take place. This operation is
absolutely vital if brazing operations on the pipework are to take place.
Ensure that the outlet for the vacuum pump is not close to any ignition
sources and there is ventilation available.
16. Charging procedures
In addition to conventional charging procedures, the following
requirements shall be followed:
• Ensure that contamination of different refrigerants does not occur
when using charging equipment. Hoses or lines shall be as short as
possible to minimize the amount of refrigerant contained in them.
• Cylinders shall be kept upright.
• Ensure that the refrigeration system is earthed prior to charging the
system with refrigerant.
• Label the system when charging is complete (if not already).
• Extreme care shall be taken not to overfill the refrigeration system.
• Prior to recharging the system it shall be pressure tested with OFN.
The system shall be leak tested on completion of charging but prior
Information on Servicing
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