Splicing of different size cables

[Shameem]

Is there any NEC code violation for splicing two different size cables. Scenario as mentioned below :


The main cable from distribution panel to a load is 3C-150mm2+1C-70mm2 (XLPE/SWA). We are running shot on the cable. We have a bigger size cable (3C-185+1C-90mm2 , XLPE/SWA )available with us.


We would like to know splicing two different cable size (above mentioned) violates any NEC code.

 

[winnie]

The use of metric cable sizes suggests that this is an application not governed by the NEC but rather a different electrical safety code.

As far as the NEC is concerned, you can change conductor sizes as long as you use proper splicing techniques, junctions are accessible, and all segments of the circuit are properly protected and meet the requirements of the load served. In other words, if you follow all of the rules for splices and conductor sizing, there is no restriction on changing size.

One requirement sometimes missed: if the circuit conductors are increased in size, you are also required to increase the size of the equipment grounding conductor.

-Jon