Coltech MDDE-10DEN3-QA3 - Refrigerant Handling and Leak Detection

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ENGLISH
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 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 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. 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, 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.