holes in the top of consumer units

[soulman]

Hi, quick question often when installing consumer units. The guy i work with just knocks out a hole in the top of consumer unit to fit the main tails and bonding. Sometimes these are the square holes for example a mk board. Is this an acceptable means of installing tails? or can these holes be filled with something i,m sure that the top of a consumer is supposed to be IP rated as is the bottom.

 

[steptoe]

I usually put a piece of 2x2 trunking along, and cables entering it from the ends. that way the holes are not accessible.

Although I much prefer battering out from the wall slightly and cable entry from the rear, looks much neater and easier to cable manage inside too.

 

[soulman]

cheers steptoe that sounds good to me, some of these consumer units are very low to the floor in a cupboard and a child may try and put something into the holes.

cheers

 

[SPECIAL LOCATION]

Hi, quick question often when installing consumer units. The guy i work with just knocks out a hole in the top of consumer unit to fit the main tails and bonding. Sometimes these are the square holes for example a mk board. Is this an acceptable means of installing tails? or can these holes be filled with something i,m sure that the top of a consumer is supposed to be IP rated as is the bottom.

You are correct...

I guess you were thinking of 416.6 page 60

specifically 416.2.2

A horizontal top surface of a barrier or enclosure which is readily accessible shall provide a degree of protection of at least IPXXD or IP4X

which basically is... Protection against access by wire 1.0mm dia & 100mm length must NOT be able to touch any hazardous parts.. (Live bits!)

So it would be interesting to ask 'Captain Knock-out' how he sees that compliance is achieved?

As Steps says there are various ways to achieve this.. trunking, or using rear entry holes and mounting on battens is another

ut the kettle on :coffee

 

[a1]

So it would be interesting to ask 'Captain Knock-out'

:slap

 

[SLIPSHOD & SLAPDASH]

:Chair fall:Chair fall:Chair fall

. I much prefer battering out from the wall slightly .

Do you use a club hammer to batter the wall

I prefer to batten the CU off the wall myself

 

[binky]

Nah battering is defo more fun:innocent

Apart from steps very good solution I also occasionally employ silicone to seal around tails / cables, or if feeling really keen I get a suitable sized drill bit to make holes in top for tails. Other solution is to try and avoid top entry and use better makes of CU that have better cable knock outs / entry points such as Hager.

 

[kerching]

I gave up with battens and now mount a piece of 18mm ply or similar to the wall with plastic 'doorstops' in each corner as spacers [similar to the old porcelain 2 piece spacers]. It gaves access all round and if you want more clearance at the back of the board then double up the spacers. Probably get flamed for it, but it works for me... :coat

 

[Evans Electric]

Sounds good to me Kerch .

 

[steptoe]

I gave up with battens and now mount a piece of 18mm ply or similar to the wall with plastic 'doorstops' in each corner as spacers [similar to the old porcelain 2 piece spacers]. It gaves access all round and if you want more clearance at the back of the board then double up the spacers. Probably get flamed for it, but it works for me... :coat

bit of 20mm conduit,

thats usually what I use BTW to 'batter' out with,

not my fault my stoopid phone auto changes the words I write. :C

 

[kerching]

bit of 20mm conduit,thats usually what I use BTW to 'batter' out with,

not my fault my stoopid phone auto changes the words I write. :C

You would not wish to 'botter' it out....see Rogers Profanisaurus in VIZ! Butter 'ing' it out could also be a touch tricky... :coat

 

[steptoe]

You would not wish to 'botter' it out....see Rogers Profanisaurus in VIZ! Butter 'ing' it out could also be a touch tricky... :coat

bottering,

well, as long as I get to give Aggie the odd barnsley its OK,

yep, I do enjoy the odd peruse of VIZ, but hadnt met rogers bottering before,

 

[sellers]

I usually batten out. If I do use a knockout I silicon up afterwards.

Its the old whats supposed to happen and what does happen. They put the knockouts in to be knocked out but as soon as you do that you lose the IP rating (unless using silicon) but without the knockouts they'd probably sell less.

Don't know if any of you have come accross the more recent MEM 3 phase db's with a semi-rotary main isolater. Once the cover is on and the isolator is on, the lever rotates round and stops the cover coming off, but just by pure luck you can lift the lever up just enough before it starts to latch to remove the cover. Wonder why? maybe because if it did switch off when removing the cover they wouldn't sell any??

 

[pickleye]

Sooo.....

Top surface - 50mm bush and locknut with a dozen 2.5 t&e's not the way to go.... :innocent

I'm learning from the best.... X(

Thankfully I persuaded the joiner to box in cables to ceiling height after my wing commander knock-out :Salute left

 

[steptoe]

I usually batten out. If I do use a knockout I silicon up afterwards. Its the old whats supposed to happen and what does happen. They put the knockouts in to be knocked out but as soon as you do that you lose the IP rating (unless using silicon) but without the knockouts they'd probably sell less.

Don't know if any of you have come accross the more recent MEM 3 phase db's with a semi-rotary main isolater. Once the cover is on and the isolator is on, the lever rotates round and stops the cover coming off, but just by pure luck you can lift the lever up just enough before it starts to latch to remove the cover. Wonder why? maybe because if it did switch off when removing the cover they wouldn't sell any??

there are a few 3ph boards like that, I think some of the older MG were like that IIRC,

also, Im not too sure about the silicone TBH,

doesnt it 'eat' pvc?

 

[PC Electrics]

A couple of years ago my assessor was at pains to remind me about the need to IP rate the top surface (not that there was any noncom on the rewire he was loking at).

I too batten out from the wall with 20mm batten and then come in from the rear. Makes it tidier inside too.

 

[kerching]

I usually batten out. If I do use a knockout I silicon up afterwards. Its the old whats supposed to happen and what does happen. They put the knockouts in to be knocked out but as soon as you do that you lose the IP rating (unless using silicon) but without the knockouts they'd probably sell less.

Don't know if any of you have come accross the more recent MEM 3 phase db's with a semi-rotary main isolater. Once the cover is on and the isolator is on, the lever rotates round and stops the cover coming off, but just by pure luck you can lift the lever up just enough before it starts to latch to remove the cover. Wonder why? maybe because if it did switch off when removing the cover they wouldn't sell any??

I have recently fitted 2 800 Amp 3 phase changeover switches with door interlocks. In the instructions there is a section titled 'defeating door interlock mechanism'....and it shows you where the pin is located to allow the door to be opened whilst the switch is energised! ... :coat

 

[steptoe]

I have recently fitted 2 800 Amp 3 phase changeover switches with door interlocks. In the instructions there is a section titled 'defeating door interlock mechanism'....and it shows you where the pin is located to allow the door to be opened whilst the switch is energised! ... :coat

I think the equipment is slightly different,

a lot of the time you need to work hot to test the required parts,

Im still of the opinion though that normal domestic CU should not be able to be opened with the main sw on,

FFS old 'wylex/MEM' IIRC units had this inbuilt with a metal spring loaded interlock and a stepped switch.

 

[Revved Up Sparky]

I've done a lot of PIR's in the commercial/ industrial sector and I would say the commonest defect that I come across is a lack of IP2X/ 4X protection on distribution boards, eg, 20mm/ 25mm/ 32mm holes where a redundant SWA has been removed with no blanking grommet fitted or, as discussed above, too large a hole having been made in the top of the DB for cable entry. Other common ones are blank ways and cover screws missing which likewise present an issue with the IP2X/ 4X rule.

 

[mikep]

I batten off the wall with inch and a half batten then mdf board, cut out the knockouts on the CU place on the MDF and mark, jig out and cut the slot and route the edge of the board and the post box slot, bang it on the wall then cables up the back of the board and tails through the bottom right of the CU on show to the meter so all is neat and tidy all with trunking leading in to the back.