Type B Vital Relays - Alstom

Preventive Maintenance
4.5. ELECTRICAL TESTS
Electrical tests are made to verify the operating current values and to check contact
resistances of the relay. If the relay does not operate at the proper values, readjust the
relay to the readjustment values specified on the relay ED sheets. Relay drawing and
catalog numbers can be used with Appendix A to look up the Engineering Data (ED)
Sheet number. To determine a relay's drawing or catalog number, refer to Heading
1.2.2., Identification.
See Table 4–6 for a summary of relay specific electrical test procedures included in this
manual.
WARNING
NOTIFY AND OBTAIN PERMISSION FROM CENTRAL CONTROL
PRIOR TO PERFORMING ANY ELECTRICAL TESTS ON RELAYS.
DURING THE ELECTRICAL TESTS RELAYS ARE INTENTIONALLY,
MANUALLY ACTIVATED. THIS ACTIVATION AFFECTS THE RELAY
CIRCUIT(S) AND POSES A POTENTIAL THREAT TO RAIL SAFETY. IT
MAY PROVIDE FALSE INFORMATION, INTERRUPT OPERATION, AND
CAUSE ALARMS TO INADVERTENTLY SOUND AND/OR BE
DISPLAYED. TAKE ALL STEPS NECESSARY TO ENSURE THE SAFE
PASSAGE OF TRAFFIC IS MAINTAINED.
NOTIFY CENTRAL CONTROL WHEN TESTING IS COMPLETE AND
THE RELAY IS BACK IN OPERATION.
To power most B1relays, apply a variable current source to the coil leads, refer to the
specific relay wiring diagram in Section 2. To power an AC vane relay, see Table 4–8.
P1457, Rev. Nov/07 4–9 Alstom Signaling Inc.