Pioneer PYZ012AZUDCIPD Owner's Manual page 8

O I
PERATIONAL NSTRUCTIONS
Handling Procedures
MAINTENANCE, SERVICING, & REPAIRS (CONT'D)
Leak Detection Methods
The following methods are acceptable for detecting leaks in systems containing flammable refrigerants:
Electronic Leak Detectors: Use electronic detectors to identify flammable refrigerants; however, ensure that the
sensitivity is sufficient and recalibrate as necessary. Calibration should be performed in a refrigerant-free area.
Confirm that the detector is not a potential ignition source and is compatible with the refrigerant in use.
Calibration Settings: Set the leak detection equipment to a percentage of the refrigerant's Lower Flammability
Limit (LFL) and calibrate it to the specific refrigerant being used. Verify that the gas concentration does not exceed
25% of the LFL.
Leak Detection Fluids: Most refrigerants are compatible with leak detection fluids, but avoid detergents containing
chlorine, as chlorine can react with the refrigerant and corrode copper piping.
Safety Precautions: If a leak is suspected, extinguish all open flames in the area.
Brazing Leaks: If a refrigerant leak requiring brazing is detected, recover all refrigerant from the system or isolate it
in a section of the system away from the leak using shut-off valves. Purge the system with oxygen-free nitrogen
(OFN) before and during the brazing process.
Removal and Evacuation
When accessing the refrigerant circuit for repairs or other purposes, use conventional procedures, but adhere to best
practices due to flammability considerations. The following steps should be followed:
Remove the Refrigerant: Recover the refrigerant into appropriate recovery cylinders.
Purge with Inert Gas: Purge the circuit with an inert gas such as oxygen-free nitrogen (OFN).
Evacuate the System: Evacuate the system to remove any remaining gases.
Purge Again: Perform a second purge with inert gas.
Open the Circuit: Open the circuit by cutting or brazing as needed.
The system should be "flushed" with OFN to ensure it is safe. This flushing process may need to be repeated several
times. Do not use compressed air or oxygen for this purpose.
To flush the system, break the vacuum with OFN until the working pressure is reached, vent to the atmosphere,
then pull down to a vacuum. Repeat this process until no refrigerant remains in the system. When applying the final
OFN charge, vent the system down to atmospheric pressure to allow for safe work, especially if brazing operations
are required on the pipework.
Ensure the outlet of the vacuum pump is kept away from any ignition sources and that the area is well-ventilated.
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