Updated on 30/09/20: We’ve just posted a guide for who is responsible for what with your meter and related equipment, for gas and electricity supplies. See this guide here
The Meter Operation Code of Practice Agreement (MOCOPA) is between the UK’s Energy Suppliers and the Distribution Network Operators (DNOs).
The Agreement includes a document which classifies the way in which faults and non-compliances can be identified. It is well written, with numerous photographs.
It includes this excellent diagram, showing who is responsible for what in the area of your electricity meter:
The Agreement identifies faults with the Distribution Board (DB) equipment, which are the responsibility of the DNO. These are divided into three broad categories:
A: Emergency. A life threatening situation and requiring immediate action.
B: Remedial work required. Serious, requiring attention for safety reasons, but unlikely to cause a threat until it can be resolved.
C: Asset Condition; Requiring attention because it isn’t to the current standards.
Thus, by way of example, Code B11 Flow is a reporting category which prevents a Meter Installer from undertaking the work because there is a fuse on the Neutral supply as well as the Live.
Old Distribution Board equipment.
Sometimes there isn’t actually a fault, but your house appears to have old-style devices belonging to the DNO.
The Energy Networks Association publishes another guide with similar format, which enables such items to be identified. The Cut-out Types and Ratings Guidance has full colour photographs and the date range when that equipment was fitted.
When viewing items of electrical equipment in your home, it is important not to tamper with it. If in doubt, take a photograph and post it here on the Forum for us to see.