Midea MAD22C3WMT Passeport Technique page 8

7) ventilated area
Ensure that the area is in the open or that it is adequately ventilated before breaking into the
system or conducting any hot work. A degree of ventilation shall continue during the period that
the work is carried out. The ventilation should safely disperse any released refrigerant and
preferably expel it externally into the atmosphere.
8) Checks to the refrigerating equipment
Where electrical components are being changed, they shall be fit for the purpose and to the
correct specification. At all times the manufacturer's maintenance and service guidelines shall
be followed. If in doubt consult the manufacturer's technical department for assistance. The
following checks shall be applied to installations using flammable refrigerants:
The actual refrigerant charge is in accordance with the room size within which the refrigerant
containing parts are installed; The ventilation machinery and outlets are operating adequately
and are not obstructed; If an indirect refrigerating circuit is being used, the secondary circuit
shall be checked for the presence of refrigerant; Marking to the equipment continues to be
visible and legible. Markings and signs that are illegible shall be corrected; Refrigerating pipe or
components are installed in a position where they are unlikely to be exposed to any substance
which may corrode refrigerant containing components, unless the components are constructed
of materials which are inherently resistant to being corroded or are suitably protected against
being so corroded.
9) Checks to electrical devices
Repair and maintenance to electrical components shall include initial safety checks and
component inspection procedures. If a fault exists that could compromise safety, then no
electrical supply shall be connected to the circuit until it is satisfactorily dealt with. If the fault
cannot be corrected immediately but it is necessary to continue operation, an adequate
temporary solution shall be used. This shall be reported to the owner of the equipment so all
parties are advised.
Initial safety checks shall include:
That capacitors are discharged: this shall be done in a safe manner to avoid possibility of sparking;
That there no live electrical components and wiring are exposed while charging, recovering or
purging the system; That there is continuity of earth bonding.
7.Repairs to sealed components
1) During repairs to sealed components, all electrical supplies shall be disconnected from the
equipment being worked upon prior to any removal of sealed covers, etc. If it is absolutely
necessary to have an electrical supply to equipment during servicing, then a permanently
operating form of leak detection shall be located at the most critical point to warn of a
potentially hazardous situation.
2) Particular attention shall be paid to the following to ensure that by working on electrical
components, the casing is not altered in such a way that the level of protection is affected.
This shall include damage to cables, excessive number of connections, terminals not made to
original specification, damage to seals, incorrect fitting of glands, etc. Ensure that apparatus is
mounted securely.Ensure that seals or sealing materials have not degraded such that they no
longer serve the purpose of preventing the ingress of flammable atmospheres. Replacement
parts shall be in accordance with the manufacturer's specifications.
NOTE: The use of silicon sealant may inhibit the effectiveness of some types of leak detection
equipment. Intrinsically safe components do not have to be isolated prior to working on them.
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