Has anyone cut these before

[chris day]

hello guys

I need to put some plastic switches on some switch drops with no Earth and replace the backboxes.
The plan is all class 2 fittings and plastic switches

I have been told these old 12mm conduits and backbones are made of nickel and my multi tool won't cut them, i suspect they had wood blades as they can't be that hard to cut.

Has anyone tackled a similar job with any advice?

 

[Leesparkykent]

Just use switches that come with screw covers like BG nexus or Schneider lisse.

 

[Bobster]

Are you sure the conduit isn't the CPC?

 

[Pete999]

12mm conduit never seen that size before Chris

 

[Pete999]

hello guys

I need to put some plastic switches on some switch drops with no Earth and replace the backboxes.
The plan is all class 2 fittings and plastic switches

I have been told these old 12mm conduits and backbones are made of nickel and my multi tool won't cut them, i suspect they had wood blades as they can't be that hard to cut.

Has anyone tackled a similar job with any advice?

View attachment 37982

Cant see any fixing lugs

 

[andyb]

Cant see any fixing lugs

Looks like two holes have been drilled and threaded to 3.5mm

 

[Pete999]

Looks like two holes have been drilled and threaded to 3.5mm

Innovative.

 

[westward10]

It is probably 5/8 conduit and Rob is probably correct, that is the cpc unless it has been butchered.

 

[westward10]

Cant see any fixing lugs

I suspect there is one in each corner behind the plaster, they probably date back to the 1950s.

 

[snowhead]

They've got round internal corners.
They look like maleable cast, the same as steel conduit boxes.

 

[telectrix]

scrape a bit of the box down to bright metal. then get Tester and a wander lead from MET to box. check resistance.

 

[Rocboni]

Yep, boxes look like cast to me. They will split with a cold chisel.

 

[Pete999]

Yep, boxes look like cast to me. They will split with a cold chisel.

Not if you heat the chisel up a bit? Sorry it's the mischief in me

 

[chris day]

Yep, boxes look like cast to me. They will split with a cold chisel.

Yes they are cast like conduit boxes

 

[chris day]

The DB has been changed last year so the MECH Earth to conduit is no longer existent.

What class 2 pendants would be complaint with no earth?

 

[westward10]

Strictly speaking all insulated ceiling roses and light switches etc... are not Class II/double insulated unless they are identified as such.

 

[Pete999]

The DB has been changed last year so the MECH Earth to conduit is no longer existent.

What class 2 pendants would be complaint with no earth?

I would think any class 2 fitting would be fine.

 

[davesparks]

Class 2 fittings won't solve the fact that the conduits aren't earthed. They need to be earthed whatever the type of fitting used.
Just do the job properly and don't try to dodge the regulations.

 

[westward10]

Most ceiling roses can be unscrewed by hand leaving access to live parts hence they are not Class II or double insulated, they are merely constructed from all insulated materials.

 

[Ian1981]

Deta ceiling roses have an inside cap covering the connections when the rose is unscrewed.
Held by 2 clips.
Not saying they are class 2 just that they offer a bit more protection.
Think the design is for painters to be able to unscrew the rose and paint around without the danger of access to live or possible live parts.I think Crabtree have roses that are screwed to the base so offer a better degree of safety.