NWR Safety Advice NRA 23-01

NWR Safety Advice NRA 23-01

Testing and calibration of Live Line Indicators for use on 25 kV OLE
Issued to: Network Rail line managers, safety professionals and accredited contractors
Ref: NRA23-01
Date: 17/01/2023
Location: National
Contact: Martin O'Connor, Network Technical Head of Contact Systems AC/DC


The lifesaving rules ‘Always test before applying earths or straps’ and ‘never assume equipment is isolated – always test before touch’ can only be complied with if the Live Line Indicators used are maintained correctly. We have received reports which highlight that Live Line Indicators aren’t being tested and calibrated in accordance with the overhead line work instructions (NR/L3/ELP/27237). All approved capacitive and resistive Live Line Indicators follow the same inspection and verification process with tests being completed both weekly and annually. Weekly tests - as a minimum each Live Line Indicator must prove correct functionality; this will be verified on known live 25 kV OLE once a week and proof of the test must be documented.

Annual inspection – as well as performing weekly tests on all Live Line Indicators they should also undergo annual calibration inspection. They should be calibrated and tested by an approved accreditor. It is recommended that the calibration is carried out by the manufacturer. Both the weekly and annual inspections must take place. A self-check functional test must also be carried out prior to use. If you come across a Live Line Indicator that is outside of it's calibration date, place the item in quarantine, mark it ‘Not for Use’, and raise a close call.



B242 NWR Safety Advice NRA23-01

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