Immergas MAGIS M4-30 Use And Installation page 135

10) Repair of sealed components.
a) During repairs of sealed components, all power supplies must be disconnected from the appliance in operation before
removing the sealed covers, etc. If it is absolutely necessary that the appliance be energised during maintenance, a perma-
nently operated leak detection device must be used, at the most critical point, to prevent a potentially hazardous situation.
b) Special attention must be paid to the following to make sure that, while working on electric components, the enclosure is
not changed in such a way as to alter the protection level. This includes damage to cables, an excessive number of connec-
tions, terminals non-conforming to the original specifications, damage to gaskets, incorrect assembly of cable glands, etc.
• Check that the appliance is installed appropriately.
• Make sure that the gaskets or sealing materials are not degraded to such a point that flammable atmospheres may enter.
The spare parts must comply with the specifications of the manufacturer.
NOTE
The use of silicone sealant could inhibit the effectiveness of some types of leak detection equipment. Inherently safe
components must not be isolated before working on them.
11) Repair of inherently safe components.
Do not apply permanent inductive or capacitive loads to the circuit without first having checked that they do not exceed
the voltage and current allowed for the instruments in use. Inherently safe components are the only ones on which it is
possible to work when live in the presence of a flammable atmosphere. The test equipment must be correctly classified. Only
replace the components with others indicated by the manufacturer. The use of other components could trigger refrigerant
flammability following a leak into the atmosphere.
12) Wiring.
Check that wiring is not subject to wear, corrosion, excessive pressure, vibrations, sharp edges or other adverse environ-
mental effects. The check must also take into consideration the consequences of aging or of continuous vibrations coming
from sources such as compressors or fans.
13) Detection of flammable refrigerants.
Under no circumstances must potential sources of ignition be used to look for or detect refrigerant leaks. Halide torches
(or any other detector that uses naked flames) 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 their sensitivity might not be adequate or require recalibra-
tion. (The detection device must be calibrated in an area free of refrigerants). Make sure that the detector is not a potential
source of ignition and that it is suitable for the refrigerant. The leak detection appliance must be set at an LFL percentage of
the refrigerant and calibrated for the refrigerant used; the appropriate percentage of gas is confirmed (25% at maximum).
Leak detection fluids can be used with the majority of refrigerants, but detergents containing chlorine must not be used as
this element can react with the refrigerant and corrode the copper pipes. If there is a suspected leak, all naked flames must
be removed or put out.
15) Removal and discharge.
When interacting on the refrigerant circuit to perform repairs or for any other purpose, conventional procedures must be
followed. It will be important to abide by consolidated practice as flammability is a very important factor to be taken into
consideration. The following procedure must be complied with:
• Remove the refrigerant;
• Purge the circuit with inert gas;
• Discharge;
• Purge again with inert gas;
• Restore the circuit by cutting or performing a brazing intervention.
The refrigerant charge must be recovered in appropriate recovery cylinders. The circuit must be washed with nitrogen to
remove impurities from the appliance. This process might need to be repeated several times.
Compressed air or oxygen must not be used for this activity.
Make sure that the vent of the vacuum pump is not exposed to triggering sources with a simultaneous ventilation source.
135