Discuss 25mm Knockout Metal Clad Boxes. in the Electrical Forum area at ElectriciansForums.net

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RDB85

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I’m looking for some metal clad sockets. But I need 25mm knockouts. Does anyone know any surface mounted metal clad sockets that have them? MK do some nice ones but they are only 20mm knockouts.
 

Would take you ages using one of those.

The RS link was just the first cone cutter that came up on google. Aldi or Lidle usually have sets of 3 or 4 sizes for less than a tenner.


Would be better for you, wont last long going through any decent metal, but the soft metal back boxes are made from will be no issue.
 
I’m looking for some metal clad sockets. But I need 25mm knockouts. Does anyone know any surface mounted metal clad sockets that have them? MK do some nice ones but they are only 20mm knockouts.
In the USA parts houses have 1/2 to 2 inch knockouts, and you can even get them for stainless steel. If you get on the internet and look up City electric supply or electrical distributors inc.
 
In the USA parts houses have 1/2 to 2 inch knockouts, and you can even get them for stainless steel. If you get on the internet and look up City electric supply or electrical distributors inc.

Something must be getting lost in translation here, to us a knockout is basically a pre punched hole in an enclosure.
What is a knockout in your terminology? Do you have a picture?
 
Something must be getting lost in translation here, to us a knockout is basically a pre punched hole in an enclosure.
What is a knockout in your terminology? Do you have a picture?
Dave a knockout is a tool to knockout holes and to close up a hole we call a them hole seals. Sorry about the confusion
 
A word of caution.

Lots of metalclad sockets are too shallow to get a 25mm thread into without it interfering with the socket face as you put it on.

Side entry is a no chance

Top or bottom you might get away with if you are using a female conduit coupler and a bush but not if you are coming into the box with a male thread and locknut.

Rear entry shouldn’t be a problem.

Also, if this is metal conduit, you need to make sure the hole center will be in the right place when the conduit is fastened to the wall so as not to require the socket to be spaced off the wall.
 
A word of caution.

Lots of metalclad sockets are too shallow to get a 25mm thread into without it interfering with the socket face as you put it on.

Side entry is a no chance

Top or bottom you might get away with if you are using a female conduit coupler and a bush but not if you are coming into the box with a male thread and locknut.

Rear entry shouldn’t be a problem.

Also, if this is metal conduit, you need to make sure the hole center will be in the right place when the conduit is fastened to the wall so as not to require the socket to be spaced off the wall.

Thanks, this is the conduit that I have: 25mm Flexible Conduit Pack c/w 10 Glands - Black - https://www.tlc-direct.co.uk/Products/AF25BSB.html

The cable I am using is 4mm NYY 3 Core cable. I went to a few wholesalers who said that I would need 25mm PVC Glands and would be best with 25mm Conduit, as 20mm would be too tight on the glands and the conduit would be a pain to pull the cable through, would be better with the bigger conduit and glands.
 
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I personally don't like 25mm metal tube and for the reasons above won't use it.
I had a school job where I tried to use it for the switch drops and it was a right pain.
The main electrician agreed and we changed the spec to using 2x20mm drops instead. The 2x20mm worked out a tiny bit more on materials but the installation was so much better.
I can't think of a single time where I would use 25mm metal tube
 
The cable I am using is 4mm NYY 3 Core cable. I went to a few wholesalers who said that I would need 25mm PVC Glands and would be best with 25mm Conduit, as 20mm would be too tight on the glands and the conduit would be a pain to pull the cable through, would be better with the bigger conduit and glands.
 
The cable I am using is 4mm NYY 3 Core cable. I went to a few wholesalers who said that I would need 25mm PVC Glands and would be best with 25mm Conduit, as 20mm would be too tight on the glands and the conduit would be a pain to pull the cable through, would be better with the bigger conduit and glands.
Do y’all have rolls of wire you can buy instead of cables. My experience with European equipment only has cable that comes with the machines, then you have to over size the conduit just to pull the cable. We in the USA have to protect the cables according to the NEC. They are certain installations that we don’t have to run pipe. In the USA I would say that 50% of electrical work here is running conduit to get wires from point A to point B
 

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