John Sowman asks this question, which concerns a student accommodation electrical installation with a found borrowed neutral, and whether it needs fixing, and if not, which Code to apply. It has been answered by SELECT (Theme – Distribution Equipment):
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Question: I have come across a borrowed neutral while carrying out an electrical installation condition report (EICR).
The electrical installation is in a large house with student accommodation and is subject to HMO licencing. The lighting for the house is spread over two typical circuits - basement and ground floor, first floor and second floor. Emergency lighting is spread throughout property also.
Does the borrowed neutral need to be rectified completely, or can we double up into one circuit breaker - and hence a single neutral termination - and report the condition as a Code 3?
Your advice would be greatly appreciated.
Answer: Borrowed neutrals can be a problem particularly when a ‘split-board’ configuration is being installed with RCDs. If this is identified during a periodic inspection, it may not be something that is in need of immediate attention.
However, the condition should be identified - perhaps by a Code 3 coding on the EICR, and the client advised of the benefits of rectifying the problem.
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