32mm Holesaw in Metal Consumer Unit knock out - balls up!

[Noob2013]

Hi all,

I was dreading drilling a 32mm hole in the top of a Hager metal Consumer Unit for a 25mm Swa. There are square knock outs all along the top and my worse fear was the knock out coming out.

Anyway, there is limited room so I had no choice but to terminate the swa in the consumer unit.

I started drilling the hole and all was fine until the very last bit - the knock out came out!

So I now have one of the square knock outs in the top of a hager board missing with a half circular hole.

Possible due to lack of experience but how can I gland the swa now?

I was thinking I could have a square piece of metal either side of the costumer unit with a 32mm hole in each to fix it securely.

Any ideas much appreciate

 

[Octopus]

I don't have an answer but have been pondering this one too!

Shame the CU manufacturers don't have answers and more shame to the IET for implementing such a stupid reg

 

[midgetman]

Terminate into a metal box first which is up against the hole and feed cable through there. Feel for ya lol

 

[Octopus]

The OP did say he had limited space!

 

[midgetman]

Oh yes lol

 

[Leesparkykent]

Bolt a plate over the top and re-drill hole.

 

[Barrie Patrick]

I think, if possible I'd take a jig saw to the top of the CU and take out or put as big a slot in the top as I could and then plate it with some metal sheet, maybe cutting something like a piece of trunking or adaptable box lid. then terminate the armoured into it and possibly slot the rest for any sheathed cables. Just be careful you get rid of sharp edges, grommet strip or maybe piece of Truflex? and make it look as good as you can? Barrie

 

[Noob2013]

Cheers for the advice.

I think I'll try the idea me and Leesparkykent had with use a piece of metal.

I just had a thought, the large oval knock outs I took out for rear cable entry are big enough and will look better as they are the same colour and finish as the consumer unit

 

[Octopus]

The CU manufacturers need to start selling "blank" kits!

 

[malcolmsanford]

Plate is the only realistic way forward now.

But in future when drilling something like this put a piece of 9.5/12.5 mm plywood under it held in place with a c clamp. Should stop the knockouts from falling out

 

[7029 dave]

Have not fitted CU for long time, why the hell are knockouts square.? square terminations these days.? lol

 

[Dizzy_Maskell]

For me make a new plate and pre drill this so fits nicely over balls up and your glans holds it all together !

 

[topquark]

Yep, plate it (and maybe put some high temp sealant around it).

Won't help here but the newer Contactum boards have 32mm knockouts on both sides (top right side and top left side) and also on the bottom right and top right. Not a recommendation as I don't like the fit of the front, but for future ref.

 

[Englishman]

Not any help now, but you could possibly drill a smaller hole and then open it up with one of those cone cutter things, designed to open metal holes up.

 

[Richard Burns]

Have not fitted CU for long time, why the hell are knockouts square.? square terminations these days.? lol

For mini trunking entry of cables, perhaps?

For me make a new plate and pre drill this so fits nicely over balls up and your glans holds it all together !

An interesting turn of phrase you have there ! mg_smile:

 

[Sintra]

Bolt a metal besa box lid on and re-drill.

 

[Ryan Scott]

You could get your grinder and cut a slot out of the top of the CU and stick a bit of 3 or 4 inch trunking on top of that depending if you have many cables coming into it

 

[NDG Elecs]

Not any help now, but you could possibly drill a smaller hole and then open it up with one of those cone cutter things, designed to open metal holes up.

Not a bad idea at all. I wander whether the knock out would still hold firm though. Malcolm's idea should allow for the hole to be drilled neatly. Silly design by the manufacturers, they should have a couple of different options for the actual enclosure. Maybe they should do a bit of market research, asking sparks their views..

 

[Englishman]

May hold but may not. The horrible "knock outs" on the back of the Crabtree Starbreaker would hold though, they just refuse to ever come out.

 

[HandySparks]

For me make a new plate and pre drill this so fits nicely over balls up and your glans holds it all together !

...An interesting turn of phrase you have there ! mg_smile:

Indeed, I was about to make the same comment. :biggrin5:

A sketch of the final assembly could cause offence!