Areva MCAG 19, Service Manual

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Page 8
5.2 Operating at the incorrect values
Check plug settings, and xI
s
settings.
Check knob on xI
s
, the dot on the potentiometer skirt should be in line with the
setting mark when the potentiometer os rotated fully anticlockwise.
Check mechanical settings-see Section 4.
Check values and adjustment of potentiometer, this can be damaged if overloads are
left on too long. See Publication R6035 for ratings.
Current supply not sinusoidal.
Inaccurate ammeter.
5.3 Output contacts
Contacts making mechanically, but open circuit at case terminals.
Check wire diagram.
Check connections to module terminal block and relay contacts.
Contacts contaminated- these should be cleaned with a burnishing tool, supplied in
relay tool kits
On on account should knifes, files or abrasive materials be used.
Check mechanical settings as per Section 4.
5.3.1 Output contacts not operating mechanically
Push rods not correctly located.
Check electrical connections.
Flag spring may be distorted holding the armature open
Section 6. SPARES
When ordering spares, quote the full relay model number and any component
reference numbers, or briefly describe the parts.
Repairs
Should the need arise for the equipment to be returned to GEC ALSTHOM T&D
Protection & Control Limited for repair, then the form at the back of this manual
should be completed and sent with the equipment together with a copy of any
commissioning test results.