The engineering practice of shielding, filtering, or isolating sensitive communication and signalling networks so they are not disrupted by high-voltage traction or transmission systems. This is especially critical in electrified railways, where massive fault currents or harmonic distortion from locomotives can induce dangerous voltages in trackside cables. Techniques include using twisted pairs, specific grounding arrangements, and specialized isolation transformers.
We need to verify the immunisation of the track circuits before we energize the new overhead traction line.
Also heard as
- immunization
Related terms
EMC
Electromagnetic compatibility: a product neither upsets nearby equipment with its noise nor gets upset by theirs.
Crosstalk
Unwanted coupling of a signal from one conductor or channel into a neighbouring one.
Conducted interference
Electrical noise or unwanted signals that travel along physical wires and cables.