Type B Vital Relays - Alstom

Troubleshooting
5.4. FIELD TROUBLESHOOTING
Troubleshooting procedures are provided in a logical order. The procedures must be
performed in the given order to be correct. Any deviation from the order can result in an
incorrect diagnosis or indication. This section covers only those troubles most frequently
encountered during equipment operation. If a specific concern occurs that does not
appear in this section, refer to the appropriate functional description in Section 2, and
isolate the problem to a listed functional area or to a defective assembly or
subassembly.
Troubleshooting diagrams, in the form of fault isolation diagrams begin with a
malfunction symptom. Then, based on observation/tests by the maintainer, the
diagrams branch out to isolate probable causes of the malfunction. When a malfunction
is external, a reference is given to refer the maintainer to the probable fault area for
further troubleshooting.
NOTE
After performing replacements, repairs, or adjustments the maintainer
must repeat the troubleshooting procedure.
Troubleshooting symbols are described in Table 5–1. Fault isolation diagrams are
provided as follows:
• Figure 5–1, DC Relay Does Not Pick
• Figure 5–2, DC Relay Does Not Release
• Figure 5–3, AC Vane Relay Does Not Pick
• Figure 5–4, AC Vane Relay Does Not Release
• Figure 5–5, Microchron II Timer Relay (DC or AC) Does Not Pick
• Figure 5–6, Microchron II Timer Relay (DC or AC) Does Not Pick
P1457, Rev. Nov/07 5–2 Alstom Signaling Inc.