Concealed joints again!

[JohnW2]

Current discussions in this forum about an underground joint in SWA cable have caused me to refresh my knowledge of what the regs 'actually say', and that ha led me to something I've never considered before.

In terms of underground joints, for fairly obvious reasons the regs exclude such joints from needing to be 'accessible for inspection and testing'.

In the more usual situation of joints in cables concealed within walls, below floorboards or above ceilings (hence not 'accessible foor inspection and testing') we generally interpret the regs (and advise people accordingly) as saying that such joints have to be either 'mechanical' (e.g. crimpled, soldered, brazed or welded) or else achieved with "MF" connectors/JBs (with 'sprung' terminals). In particular, we say that joints made using screwed terminals are not acceptable if 'inaccessible'.

However, I've just been reminded that the list of joints which do not need to be 'accessible for inspection and testing' not only includes 'underground' ones, but also includes "a compound-filled or encapsulated joint".

Taken as written, that would seem to mean that, per regs, one could have an 'inaccessible' joint made with screwed terminals if those terminals were enclosed in something (maybe a 'traditional' JB?) filled with 'a compound' (such as 'magic gel").

Comments on a postcard?

 

[Harry Bloomfield]

I've never used gel, always resin compound, some quite large cable, some quite small, mains signal cables, but always crimped, or soldered.

 

[JohnW2]

I've never used gel, always resin compound, some quite large cable, some quite small, mains signal cables, but always crimped, or soldered.

I've used both in my time, probably always soldered (I'm nervous about crimped joints).

However, as you will presumably realise, I was talking about what the regs seem to allow (for 'above ground non-accessible joints) and that would appear to include any sort of joint (including screwed) if it is within gel or resin - unless you can find some other way of interpreting the reg?