Type B Vital Relays - Alstom

Troubleshooting
5. SECTION 5 – TROUBLESHOOTING
5.1. GENERAL PHILOSOPHY
Troubleshooting helps to determine defective parts of equipment requiring repair or
replacement. This is done through fault isolation diagrams and special instructions.
5.2. GENERAL TROUBLESHOOTING
General troubleshooting can be summarized as follows:
• Understand and define the problem.
• Confirm the problem.
• Isolate the fault.
• Perform corrective action.
• Verify system operation.
Standard troubleshooting, such as verifying wiring and energy, can be used to identify a
failure.
It is recommended that the following items be checked when troubleshooting a Type B
relay problem:
• Current Test Post (E Post) - check for tightness of spanner nut (if present, not all B
relays have this post)
• Plugboard Contacts - check that relay is properly seated
• Voltage – check that it is provided to the coil
5.3. RELAY TROUBLESHOOTING TOOLS
See Appendix C for a summary of B relay tools.
P1457, Rev. Nov/07 5–1 Alstom Signaling Inc.