ABB REG316 4 Series - Fault-Finding; Likely Causes of Problems; Maintenance

REG 316*4 1MRB520049-Uen / Rev. B ABB Switzerland Ltd
4-21
4.2.3.6. Maintenance
4.2.3.6.1. Likely causes of problems
Should the protection become defective, i.e. operate incorrectly,
the cause may be one of the following
· The shaft grounding brush is making poor contact ® see
Section 4.2.3.6.2.
· The calibration of the YWX111-11/-21 is incorrect ® see
Sections 4.2.3.5.2. and 4.2.3.5.4.
· The YWX111-11/-21 is grounded in the cubicle (terminal 3)
causing a duplicate ground
® see Section 4.2.3.4.2.
· The protection is too sensitive (the setting for the level of
leakage resistance is too high) or the time delay t is too short.
4.2.3.6.2. Maintenance
The ancillary unit requires no special maintenance. As with all
safety systems, however, it should be tested at regular intervals.
This can be carried out as described in Section 4.2.3.5.
The shaft grounding brush should be checked and cleaned at
frequent intervals and the contact pressure adjusted as neces-
sary.
4.2.3.7. Fault-finding
Fault-finding is confined to testing the device according to Sec-
tion 4.2.3.5. to determine whether it operates correctly. Faulty
units should be returned to the nearest ABB agent or directly to
ABB Switzerland Ltd., Baden, Switzerland.