Areva MCAG 19, Service Manual

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Page 3
Section 1. INSTALLATION
1.1 General
Protective relays, although generally of robust construction, require careful
treatment prior to installation. By observing a few simple rules the possibility of
premature failure is eliminated and a high degree of performance can be expected.
The relays are either despatched individually or as part of a panel/rack mounted
assembly in cartons specifically designed to protect them from damage.
Relays should be examined immediately the are received to ensure that no
damage has been sustained in transit. If damage due to rough handling is evident,
a claim should be made to the transport company concerned immediately, and
GEC ALSTHOM T&D Protection & Control promptly notified. Relays which are
supplied unmounted and not intended for immediate installation should be returned
to their protective polythene bags.
1.2 Unpacking
Care must be taken when unpacking and installing the relays so that none of the
parts are damaged or their setting altered, and must be handled by skilled persons at
all times.
Relays should be examined for any wedges, clamps, or rubber bands necessary to
secure moving parts to prevent damage during transit and these should be removed
after installation and before commissioning.
Relays which have been removed form their cases should not be left in situations
where they are exposed to dust or damp. This is particularly applies to installations
which are being carried out at the same time as construction work.
1.3 Storage
If relays are not installed immediately upon receipt they should be stored in a place
free from dust and moisture in their original cartons and where de-humidifier bags
have been included in the packing they should be retained. The action of the de-
humidifier crystals will be impaired if the bag has been exposed to ambient
conditions and may be restored by gently heating the bag for about an hour, prior to
placing it in the carton.
Dust which collects on a carton may, on subsequent unpacking, find its way in to the
relay; in damp conditions the carton and packing may become impregnated with
moisture and the de-humidifying agent will lose its efficiency.
The storage temperature range is –25
°
C to +70
°
C
1.4 Site
The installation should be clean, dry and reasonably free from dust and excessive
vibration. The site should preferably be well illuminated to facilitate inspection.
An outline diagram is normally supplied showing panel cut-outs and hole centres.
For individually mounted relays these dimensions will also be found in Publication
R6035.
Publication R7012 is a parts catalogue and assembly instructions. This document
will be useful when individual relays are to be assembled as a composite rack or
panel mounted assembly.