NR NR/L2/SIG/11655 ISSUE 3 PDF

This standard applies to signalling cable & wire insulation degradation on the infrastructure.

Inspection of wire insulation degradation on the signalling infrastructure is covered by NR/L3/SIG/31655.

Purpose

The safety integrity of the signalling system is at risk if cable/wire insulation is allowed to degrade. This standard specifies:

• The requirements for inspections
• The precautions to be taken during inspections
• Constraints to be placed on work where degradation is detected, and
• Action to be taken to remove degraded wiring/installations.

When the insulation degrades, the inner conductor can become exposed and come into contact with other exposed wires and terminals. The risks are that:

• Contacts are bypassed in a circuit
• Circuits are falsely energised
• Electrical shock, especially when carrying out hand tracing.