Guidance Note 3 Inspection and Testing 2022 Appendix C

While the polarities are correct at the meters, (although the colours/ tapes are reversed at the terminals), BOTH consumer units are indeed reverse polarity. Disconnection of the main fuse is required by the DNO, and the electrical installation given a thorough check over, including outside buildings/circuits.

UKPN2025 said:

While the polarities are correct at the meters, (although the colours/ tapes are reversed at the terminals), BOTH consumer units are indeed reverse polarity.

I'm not seeing that. Line conductor on right hand side of isolator (terminal 1), feeding through to busbar below on RHS (terminal 2)... neutral link from bottom-left to neutral busbar not shown.

In fact, whilst now not always followed, traditionally, terminals in single-phase systems were frequently arranged to go "clockwise" from the top, similar to the concept of line at the bottom-left if PE at top-centre in socket-outlets.

Of course, when providing illustrations for industry guidance, making things look too much like a particular product from a real manufacturer is to be avoided.

I do, however, take the point that it wouldn't be easy to route the tails inside the CU in the Figure in Appendix C.

UKPN2025 said:

While the polarities are correct at the meters, (although the colours/ tapes are reversed at the terminals), BOTH consumer units are indeed reverse polarity.

I'm not seeing that. Line conductor on right hand side of isolator (terminal 1), feeding through to busbar below on RHS (terminal 2)... neutral link from bottom-left to neutral busbar not shown.

In fact, whilst now not always followed, traditionally, terminals in single-phase systems were frequently arranged to go "clockwise" from the top, similar to the concept of line at the bottom-left if PE at top-centre in socket-outlets.

Of course, when providing illustrations for industry guidance, making things look too much like a particular product from a real manufacturer is to be avoided.

I do, however, take the point that it wouldn't be easy to route the tails inside the CU in the Figure in Appendix C.

gkenyon said:

I do, however, take the point that it wouldn't be easy to route the tails inside the CU in the Figure in Appendix C.

Fine stranded tails! (As discussed previously.)