Toyotomi SONZAI Series User Manual page 64

DEHUMIDIFIER
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 all refrigerant
systems.
Electronic leak detectors may be used to detect refrigerant leaks but, in the
case of fl ammable 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 confi rmed.
Leak detection fl uids 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 fl ames 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 fl ammable
refrigerants, oxygen free nitrogen (OFN) shall then be purged through the
system both before and during the brazing process.
REMOVAL AND EVACUATION
When breaking into the refrigerant circuit to make repairs – or for any other
purpose – conventional procedures shall be used. However, for fl ammable
refrigerants it is important that best practice is followed since fl ammability 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.
GB
64