External junction box - gland nut seized

[JohnD]

or you can use a Dremel or similar to slit the nut up one or more sides, and it will probably open up and break off when you put the spanner on it.

 

[SplanK]

Thought I would just update this thread.... I managed to get the job done!

Tried penetration fluid (plus gas), but despite a reasonable soaking over a few days, the nut would still not budge. I noticed that the casing had cracked, so knowing I had a replacement to hand I thought I could get more access if I broke away the rest of the box around the nut.

Still not for budging however I was able to free off the top section of the gland nut assembly. A quick trip to B&Q for a replacement assembly, and thankfully I was able to replace the top part of the assembly rather than the entire lot.


All back together now in a new box, and ensured that there was a good air gap between soil/plants and the bottom of the box to try and avoid a repeat of damp ingress.

 

[ban-all-sheds]

You have, I hope, done a loop impedance test to confirm that the connection to the armour is sound?

 

[SplanK]

I have not, however within this box, there is no connection to the armour. I replaced like for like only as the box was compromised (as per original post, 3 of the 4 screw mounts had snapped...).

I would assume (yes, I know its dangerous to assume things like this....) that the earth bonding was done at the other end where the SWA is joined to the internal house wiring. I have found basic documentation which shows that this was a 'professional' install when the conservatory was built and the garden re-landscaped. Although given I don't know the full history, or know if the earth is even connected to the SWA at t'other end (yet to open up that box!) I suppose it would be prudent to do some further checks.

Thanks

 

[333rocky333]

You could replace the locknut with an "Earthing Nut" then put a fly lead earth cable from that and connect to, I assume one of the cores that is used as earth, that core should be marked green and yellow realy.
You say you used only part of the new gland, did the threads match and tighten the thing up on the steel armour, im confused why you didnt use all the new gland bits, seeing as you had it all dismantled anyway

 

[conny]

My thoughts exactly Rocky. Looking at the photos I suspect what is left on the cable is the lower gland nut covered by the rubber shroud.
If that is the case, (I can't see any armour wires), then the new gland probably hasn't gripped the swa correctly.

 

[ericmark]

I would assume (yes, I know its dangerous to assume things like this....) that the earth bonding was done at the other end where the SWA is joined to the internal house wiring.

This is a problem we are all assuming to some point, we don't really know. To me that does not look like an external gland, but I could be wrong, it seems that a core has been used as an earth, but again I could be wrong. The problem is we don't always export the house earth and as you say dangerous to assume. It may have been done by an electrician but I would not have put a JB so close to the ground, I assume he was trying to make it look neat.

To do a loop test needs equipment and skill, I would say likely best option is to get a plug in tester with a loop test like the EZ150 and that should do a good enough job. But even they cost around £50 so if a one off job then find an electrician who can plug in his loop impedance tester for you. Just in case it is TT which I think is unlikely you need to read that paperwork you found. I would expect TN-C-S but it could be TN-S or TT what does it say?

 

[333rocky333]

From the start of the thread, there appears to be something connected with the earth