Midea MDDM20, Owner'S Manual & Installation Manual

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Safety Precautions
 Page 6 
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.
8)Checks to the refrigeration 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 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
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.
9)Checks to electrical devices
7.Repairs to sealed components
Do not apply any permanent inductive or capacitance loads to the circuit without ensuring that this will
not exceed the permissible 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
atmosphere. 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.
8.Repair to intrinsically safe components
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.