Mitsubishi SRK20ZSX-W Technical Manual page 153

The following checks shall be applied to installations using flammable refrigerants including R32:
– The charge size 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;
– Refrigeration 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 re-
sistant to being corroded or are suitably protected against being so corroded.
►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 no live electrical components and wiring are exposed while charging, recovering or purging the system;
• that there is continuity of earth bonding.
►Repairs to sealed components
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.
► 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 the apparatus is mounted securely.
Ensure that seals or sealing materials have not degraded to the point that they no longer serve the purpose of preventing the in-
gress of flammable atmospheres.
Replacement parts shall be in accordance with the manufacturer's specifications.
►Repair to intrinsically safe components
(1) Do not apply any permanent inductive or capacitance loads to the circuit without ensuring that this will not exceed the per-
missible voltage and current permitted for the equipment in use.
Intrinsically safe components are the only types that can be worked on while live in the presence of a flammable atmo-
sphere. The test apparatus shall be at the correct rating.
Replace components only with parts specified by the manufacturer. Other parts may result in the ignition of refrigerant in
the atmosphere from a leak.
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'18 • SRK-T-234