Teddington SECO STEEL 80 Manuel Technique page 30

6.1.8 Checks to electrical devices
EN
6.2 Repairs to sealed components
6.3 Cabling
6.4 Detection of flammable refrigerants
6.5 Leak detection methods
6.6 Removal and evaluation (flushing)
30 M.SECO STEEL 80-02 Manual_ITA_UK_DE_FR_ES - 09/03/2021
Initial safety checks and component examination procedures must be included in the repair and
maintenance of electrical components. IT IS FORBIDDEN to proceed with the power supply of the
unit until the fault has been resolved satisfactorily
Initial security checks must include:
- that the capacitors are discharged: this operation must be carried out safely to avoid the possibility
of creating sparks;
- that there are no live electrical components and that the cables are not exposed while charging,
recovering or bleeding the system;
- that there is continuity in the earth connection.
1) During repairs to sealed components, all power supplies must be disconnected from the appliance
being worked on before removing the sealed covers.
2) Particular attention must be paid to the following to ensure that, when working on the electrical
components, the casing does not alter so as to compromise the level of protection. Attention should
also be paid to damage to the cables, previous modifications of the circuits that are not consistent
with the technical documentation supplied with the unit., Damage to the gaskets, incorrect fixing of
the cable glands.
Make sure that the equipment is securely mounted.
Make sure that the gaskets and sealing materials have not deteriorated to the point that they are no
longer suitable for the purpose of preventing development in flammable atmospheres. Spare parts
must be in accordance with the manufacturer's prescriptions.
NOTE The use of silicone sealant can impair the effectiveness of some types of spill detection
instruments.
Check that the cables are not subject to wear, corrosion, excessive pressure, vibrations, sharp
edges or any other situation that could compromise their continuity and / or insulation. The check
shall also take into account the effects of aging or continual vibration from sources such as
compressors or fans.
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.
The following methods of detecting spills are believed to be acceptable for systems that contain
flammable refrigerant fluids.
Electronic leak detectors should be used to detect the presence of flammable refrigerant fluids, but
their sensitivity may not be adequate or may need to be re-calibrated. (The detection equipment
must be calibrated in an area without refrigerant fluid). Make sure that the detector is suitable for
operating in an Atex atmosphere (at least zone 2), that it is suitable for the refrigerant fluid used.
The detection equipment must be set at a percentage of the LFL of the refrigerant fluid and must be
calibrated for the refrigerant fluid used, and the appropriate percentage of gas (maximum 25%)
must be confirmed.
| Fluid leak detectors are suitable for use with most refrigerant fluids but the use of detergents that
contain bleach must be avoided as they can react with the refrigerant fluid and corrode the copper
piping network.
If a leak of refrigerant fluid is found that requires repair with hot work (e.g. brazing) it is necessary to
proceed with an accurate flushing procedure with inert gas, according to the indications given in the
following point.
When performing maintenance operations on parts of the refrigerant circuit that do not provide for
the use of ignition sources and / or hot work, conventional procedures can be followed. If, on the
other hand, interventions involving the use of ignition sources and / or hot work must be carried out,