Type B Vital Relays - Alstom

Corrective Maintenance
Table 6–11. Mechanical Test and Adjustment Procedure (Cont.)
Step
Procedure
5 Verify the armature air gap measurement is as specified on the specific relay’s
ED sheet. A feeler gauge of the same thickness as the specified air gap must
pass freely between the armature and core heads at any point, except at the
fixed safety pins, when the relay is energized.
ARMATURE
CORE
SAFETY PINS
LOCATED AT
THE CORE
HEADS
CORE
6 If the armature air gap is not acceptable, adjust the armature gap with the
adjustable residual screw to obtain the required air gap. The screw must be
locked tight in place by the lock nut provided.
7 Verify the bridge travel measurement is as specified on the specific relay’s ED
sheet.
Use a feeler gauge of the same thickness as the specified air gap to verify the
air gap between the bracket and the armature stop screw when the relay is
energized.
ARMATURE
STOP SCREW
GAP
BRACKET
P1457, Rev. Nov/07 6–18 Alstom Signaling Inc.