In article ,
says...

On Sunday, March 12, 2017 at 11:03:13 AM UTC-4, wrote:
On Sun, 12 Mar 2017 17:44:58 +0630, yky wrote:

What connector is used to splice 5 mm power cable? Cannot be wire nut,
can it? Photo links are highly appreciated.

Split bolt or a set screw style connector

https://static.grainger.com/rp/s/is/image/Grainger/6CYZ0_AS01?$lgthumb$
https://www.amazon.com/Panduit-PNLC-.../dp/B00B5P52UM

Or a splice kit which includes a butt type connector and heat shrink
tubing. Also depends on where it is, underground?, etc?

That equals a # 10 in American wire. Wire nuts are ok, crimp ring
terminals with screws can be used with insulation over it. As said ,
depends on where it is used at and if more than 2 wires are to be
connected.