Black enamel

[333rocky333]

On a job today, there was 4 pyros glanded into a fairly new 4x4 knockout box.

There was no earth continuity between two of the glands though.

It appears the black enamel is completely insulating both the gland body and the lockring from the box.

I have only used galv boxes, so is this possible.

How would you prepare the hole normally on these boxes or do you just file the edge round the hole,.

would serrated steel washers be a better option, the intended plan is to fit pirahna earth nuts with the spikes and bond all four together as well.

 

[Lectrician]

Using black enamal conduit, adaptable boxes and circ boxes was fairly normal a little while ago. Certainly looks better than galv.

You are meant to use serated washers with the enamal conduit bits to dig through the enamal - You then repainted over the top with your small tin.

I recently tried to do an R1+R2 test a little bit backwards - testing at the DB. I put my crock clip on a galv conduit coupler between the DB and a lightswitch. I did not have continuity! The coupler was rather oddly insulated from the DM by the DB's paint. Really odd. A quick whack gave it continuity, and I then loosened it, scrapped paint internally and did it up tight. I would have fitted a serated washer if I had some on board.

It is usually the knockout holes that have this issue, not the drilled ones.

 

[333rocky333]

Thanks lectrician
with galv the connection 's something you take for granted,usually.

Done black enamel conduit but never ever used a B/E sguare box for some reason.

It was a knockout box, I suppose like you say, a holesaw would have exposed some of the metal and would not have created the problem.

 

[tim west]

deleted

 

[holmslaw]

..

 

[333rocky333]

Bushes used to be quality

now though the head is barely bigger than the shaft.

 

[RF Lighting]

My bush spanner doesn't fully tighten new bushes as there is so little brass on the hexagon part.

It is fine with old bushes.

Doesn't that tell you something