Type B Vital Relays - Alstom

Preventive Maintenance
Table 4–2. Typical B1 Relay Visual Inspection Procedure (Cont.)
Step
Procedure
4 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.
5 If components inside the cover are loose, mis-aligned, or required cleaning,
remove and replace the relay.
6 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 4–5 Alstom Signaling Inc.