Do you know about Cable Joints?

Question

I want to terminate a 25mm cable in a distribution board. The board wont take termination bigger than 10mm. I intend to use cable compression connectors to reduce cable size to 10mm or a scotch-cast. Can you advice the implication of this i.e voltage between the feed and point of connection to the joint.

I feel this will be irrelevant because i intend to run the 100mm for 3-5m then join it to the 25mm cable before the cable starts its long run.

Kindly advice please.

Answer 1

If you join the cable (which is not good practise) you will need to use a protective device (mccb, mcb, etc) rated for the 10mm cable not the 25mm.

Answer 2

You question is a little confusing. If your board will not take the 25mm cable then it will not likely take the current that the cable is rated for. On the other side of things, by reducing your cable size at any point will reduce its current carrying capacity.

I have experienced times where the cable size has been increased because of volt drop and so doesn't actually require its full current carrying capacity. In this case, it may be OK to reduce it at some point providing the source protection will not allow the current to exceed the "reduced" point. The problem is that I don't know of any recognised connectors to do this so your best bet would be to get a board that will take your cable and avoid any risk.

Answer 3

Assuming the safety aspects of the circuit are not compromised by reducing the cable to 10mm

You can bolt an adaptable box under the DB or to the Side using couplings and bushes say a 150mm x 150mm x 100mm and install 25mm din rail mounted connectors inside. Terminate the 25mm cable I assume SWA into the Adap box and the under side of the 25mm terminations then take 10mm cable out of the opposite side of the 25mm terminations into DB

Again I assume the protective device in DB is not too high for 10mm cable. The device should be sized for the smallest conductor in the circuit in this case 10mm

Not pretty but effective.