NYY-J or HO7V-R or HO7-RN-F ? Which would you use for this?

[1capybara]

This is for wiring several machines each typically 6 to 13 amps 3 phase. We size the cable at 4 or 5 core x 4mm2. We will run the wire in cable tray. Because they wont fit in 20mm conduit, be will run the cables into a junction box, then use NYY-J in the conduit down to the machine.
There doesnt seems much difference in price of NYY-J or HO7V-R or HO7 RN-F. Which would you use?

 

[Richard Burns]

If it is internal on cable tray then there is not much to choose between them, the NyyJ will be stiffer and more difficult to dress. If there are no mechanical damage considerations then I would use the H07RNF.
Using 25mm conduit would also allow a continuous cable run, but presumably a connection problem at the machine.

 

[D Skelton]

My advice:

Take 522.7.1 into consideration and keep to the fine stranded flex.

HO7RN-F is our cable of choice for final connection to motors/machines for this reason.