Type B Vital Relays - Alstom

Preventive Maintenance
Table 4–5. Miscellaneous Relay Visual Inspection Procedure
Step
Procedure
1 Check that the relay cover and seal are not cracked, broken or discolored.
2 Verify that relay components are not loose inside the cover.
Many components are common to all B1 and B2 relays, reference Section 7 for
drawings of specific relay components.
3 Verify any contacting surfaces are clean, smooth, and not bent or mis-aligned.
4 For relays with flexible connectors, the connectors must be intact and must not
touch any adjacent parts.
Any coils must be secured in place and in good condition.
5 Verify that normally open co-acting contacts meet squarely and simultaneously
when relay is energized. Contacts should have wipe as armature goes through
to its front stop.
When relay is deenergized, normally closed contacts should meet squarely and
simultaneously. Contacts should have wipe as armature goes to its backstop.
During pick up and drop away, armature must move freely on its bearing plate.
6 If components inside the cover are loose, mis-aligned, or required cleaning,
remove and replace the relay.
7 If a relay is removed for any reason during the inspection procedure, the
mechanical tests in Section 6 may be performed as specified. The relay may not
be returned to service until the operating characteristics and conditions are in
accordance with Alstom ED sheet specifications.
P1457, Rev. Nov/07 4–8 Alstom Signaling Inc.