Type B Vital Relays - Alstom

Corrective Maintenance
Table 6–13. Microchron II Timer Electronics Replacement Procedure
Step
Procedure
1 For the DC version of this relay install the Motherboard and go to Step 5.
NOTE
Always handle printed circuit boards at a static safe station.
For the AC version of this relay, go to Step 2.
2 Place the electronics package/bracket assembly onto the relay base.
3 Confirm that the wires to the white, 4-position connector run through the notch in
the bracket.
4 Use the two flathead screws and washers from Step 3 of Table 6–12, the Timer
Electronics Disconnect and Removal Procedure, to secure the assembly to the
relay base and tighten firmly.
5 Connect the smaller, square shaped, 4-position connector P2 to the
thumbwheel board. The connector is keyed and only fits in one position.
Top View of AC Relay
(J1)
(P1)
(P2)
6 Connect the four-position connector, P1 (located close to the relay base) from
the Motherboard (DC version) or Timer board (AC version).
7 Visually inspect the relay to verify that no wires are pinched between the relay
base and the Motherboard (DC version) or Timer board (AC version).
P1457, Rev. Nov/07 6–27 Alstom Signaling Inc.