Original User Manual – AREBOS Mini Heat Pump
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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.
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.
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 shall also take into account the effects of
aging or continual vibration from sources such as compressors or fans.
13 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.
14 Leak detection methods
The following leak detection methods are deemed acceptable for all refrigerant systems. Electronic
leak detectors may be used to detect refrigerant leaks but, in the case of flammable refrigerants, 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. For appliances containing flammable refrigerants, oxygen free nitrogen (OFN) shall 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 – or for any other purpose – conventional
procedures shall be used. However, for flammable refrigerants it is important that best practice is
followed since flammability is a consideration. The following procedure shall 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 shall be recovered into the correct recovery cylinders. For appliances
containing flammable refrigerants, 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
purging refrigerant systems.
For appliances containing flammable refrigerants, 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 refrigerant
is within the system. When the final OFN charge is used, the system shall be vented down to
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