Calling all panel builders

[ColJack]

let me know what you want, how long and whether you want the ferrules with shrouds or not, and I'll get right on it..

( although we don't do 25mm² tri rated in anything other than black, we sleeve it at the ends for phase ID.. )

tri-rated also has a different current carrying capacity than regular 7 strand..

 

[ban-all-sheds]

Well - ye cannae really change the laws of physics, so apart from minor differences in resistivity from processes like annealing, copper is copper is copper, and the only significant factor that makes one cable carry more than another of the same size is how hot it can get before the insulation suffers.

Or in the case of tri-rated inside a CU, before other cables or terminations suffer...

I had a conversation earlier with a guy on the technical desk at MK, as their CU cables are 16mm², and I couldn't see how that would work at 100A. He said this Q comes up all the time, and 16mm² is just fine - they have to do temperature rise tests for BS approval, and it's OK.

So given that, I guess I'll go for 16mm²....

Still planning the layout of the board, so not sure yet what I'll need, but when I do I'll be in touch - thanks!

 

[333rocky333]

not sure if this helps

Untitled

• 333rocky333
• 18 Jul 2008
• 1

 

[NotHimAgain]

Here is a link to some cable ratings
http://www.energy-solutions.co.uk/wiring-standards.html

It gives you the current ratings for various insulation temperatures.

Note that tri-rated cable is rated at 105° C in the USA & Canada. It is rated at 90° C in the UK (so if you want to run it at 105° C BAS you will have to move )

 

[ban-all-sheds]

Yes - for some reason BS6231 only allows 90° continuous, but UL and CSA (the other two that make up the tri-) go to 105°.

Except:

BS 6231 specifies a maximum conductor temperature of 90° C for continuous use. Under certain conditions these cables can be operated at up to 105° C. Annex A of BS 6231 gives full details.

if you want to run it at 105° C BAS you will have to move

I think if stuff inside my CU got to more than the boiling point of water I'd be moving bl**dy quickly....

 

[ban-all-sheds]

Hmmm.

If I'm putting 2 cables, or 1 cable and a bus-bar into a switch/RCD terminal, are terminated cables best, or would leaving the ends bare get me a better connection?

I've been fiddling around with some terminated cables from an old MK CU and I'm not sure....

 

[Pensdown]

I wouldn't mix cables and bus bars. You should use a bus bar feeder that's made for the job. As for two stranded cables, I would leave them bare.

Edit. A lot depends on what the terminal is designed to accept.

 

[ban-all-sheds]

But surely your traditional split-load CU has a cable coming out of the bottom live of the incomer, running to the RCD, as well as the busbar for the non-RCD breakers?

I guess my design "problem" is that I'm going to have a switch incomer, downstream of which will be a mix of MCBs and DP RCBOs, and two RCDs with busbars each with a set of regular MCBs.

I know you can get pukka distribution blocks, but I was trying to avoid cables running hither and yon....

 

[plugwash]

a lot depends on the style of the busbar and the terminals. MK afaict terminate thier split load cables with a flat pin that is designed to sit nicely on top of the busbar under the terminal of a device. With a fork style busbar I would imagine you would want a fork style termination on the end of cables and so on.

 

[Lectrician]

MK also sell the interconnecting ferruled cables seperately as spares. May not be the length you want though.

 

[ban-all-sheds]

Possibly not - hence my interest in the sort of service ColJack has offered...

 

[aptsys]

I had a conversation earlier with a guy on the technical desk at MK, as their CU cables are 16mm², and I couldn't see how that would work at 100A. He said this Q comes up all the time, and 16mm² is just fine - they have to do temperature rise tests for BS approval, and it's OK.

If I remember correctly, tri-rated cable is rated for a 35 Kelvin temperature rise. So 16mm² tri-rated cable is supposed to rise by 35K at 100A.

 

[ColJack]

a 6mm or 8mm ring crimp would be nice and flat and wider than a "pin" type crimp for better termination under a clamp type terminal..

haven't you figured it out yet? it's been nearly a month...

 

[ban-all-sheds]

It's a low-priority as-and-when job at the moment...

 

[333rocky333]

If I'm putting 2 cables, or 1 cable and a bus-bar into a switch/RCD terminal, are terminated cables best, or would leaving the ends bare get me a better connection?

Ban
would reg 526.8 apply.
or does it relate to the switch/rcd terminal.