Type B Vital Relays - Alstom

Preventive Maintenance
4.2. PREVENTIVE MAINTENANCE INTERVALS
Preventive maintenance procedures are performed on B relays with the covers on and
sealed. The tests are a good check on the overall performance of the relay, and are
completed easily and quickly.
Preventive maintenance consists of three procedures:
• Visual Inspection
• Electrical Test
• Timing Test, where applicable
Table 4–1 shows the recommended preventive maintenance time intervals.
Table 4–1. Preventive Maintenance Intervals
Relay Type
Preventive Maintenance Interval
Carborne Relays
Every 6 years
Vital Wayside Relays
Every 4 years
DC Polar and Vane Relays
Every 2 years
Master (or Primary) Relays, spring tension*
Every 2 years
Microchron II Timer Relays
Every year
* Any master or primary relay of the torque type, that depends on spring tension to return contacts to the
de-energized position in noncoded continuous inductive automatic train stop or train control systems.
Vital wayside, DC Polar and Vane Relays can be inspected and tested while installed in
racks or they may be removed from service and plugged on a shop test board for
preventive maintenance. Electrical tests of relays in the relay racks are limited to
measuring operating values and comparing the values to the specifications provided in
the Engineering Data (ED) sheets. Relay drawing and catalog numbers can be used
with Appendix A to look up the Engineering Data (ED) Sheet number. To determine a
relay's drawing or catalog number, refer to Heading 1.2.2., Identification.
Carborne and Master Relays must be removed from service for inspection and testing.
Relay removal and installation procedures are provided in Section 6, Corrective
maintenance.
NOTE
Relays not passing any of the preventive maintenance tests or inspections
must be replaced and not returned to service until the operating
characteristics and conditions are in accordance with Alstom Engineering
Data (ED) sheet specifications.
P1457, Rev. Nov/07 4–2 Alstom Signaling Inc.