Type B Vital Relays - Alstom

Corrective Maintenance
Table 6–12. Microchron II Timer Electronics Removal Procedure (Cont.)
Step
Procedure
3 For the AC version of the relay, detach the smaller, white, square shaped 4-
position connector P2 from the bottom of the Thumbwheel board, by squeezing
the side tab while pulling the connector away from the Thumbwheel board.
Locate the black bracket securing the electronics package to the relay base.
Remove and save the two flathead screws that hold the bracket to the base. Put
the two flathead screws and washers in a safe place.
(J1)
(P1)
SCREWS
(P2)
BRACKET
Carefully set the electronics package/bracket assembly aside and continue to
step 5.
For the DC version of the relay, go to step 4.
4 For the DC version of the relay remove the Motherboard and carefully set the
board aside.
NOTE
Always handle printed circuit boards at a static safe station.
Continue to step 5.
P1457, Rev. Nov/07 6–25 Alstom Signaling Inc.