Hitachi air Core 600 Installation & Maintenance Manual page 17

6-8 Checks of the refrigeration equipment
• Where electrical components are being changed, they shall be fit for the purpose and 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 amount 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 used, the secondary circuit shall be checked for the leak of refrigerant;
– Marking of the equipment should be visible and legible. Illegal markings and signs hall 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 resistant to being corroded or are suitably protected against being so corroded.
6-9 Checks of electrical devices
• Repair and maintenance of 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 of sealed components
• During repairs of sealed components, all electrical supplies shall be disconnected prior to any removal of sealed
covers, etc.
• If it is absolutely necessary to have an electrical supply for equipment during servicing, then a permanently
operating form of leak detection shall be located at the most critical point to warn 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 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 sealants 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.
8. Repairs of intrinsically safe 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 for the equipment in use.
• Intrinsically safe components are the only types that can work 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 leaked in the atmosphere.
9. Cabling
• Check that cabling will not be subject to wear, corrosion, excessive pressure, vibration, sharp edges or any other
adverse environmental effects.
• The check shall also take into account the effects of aging or continual vibration from sources such as
compressors or fans.
WARNING
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Safety Precautions