There are two issues here:
1.- Canadian Code; 12-904 Conductors in raceways
(1) Where conductors are placed in metal raceways, all conductors of a circuit shall be contained in the same
raceway,
In the Canadian code there is a warning on magnetic encirclement of single conductors.
2.- A single conductor will cause heating of any ferrous material which encircles it. The heating will be from both eddy currents and from hysteresis. The same heating will occur when two conductors out of a three conductor circuit are encircled magnetically.
This effect may be mitigated by using non-ferrous connectors (die cast) and by entering through an aluminum plate or insulating (micarta) plate.
Another mitigation method that is economical in terms of both material and labour is to join the holes in the junction box with a hacksaw cut. This makes the entry effectively one hole magnetically.

Bill
--------------------
Ohm's law
Not just a good idea;
It's the LAW!

In short, it's a poor installation. Acceptable or not, it depends on your particular code and if you are referring to equipment wiring or installation wiring.

Where I am, if it is installation wiring, it would not be for two reasons, the earth conductor is not enclosed with the circuit and the circuit conductors are in different conduits.

Sounds like you should use two parallel sets of cables with smaller size that do each fit within the m63 termination or modify the terminal box so it is suitable.

It seems a bit strange to me that a motor terminal box, isn't manufactured to fit the dimension for cables and such that it needs to meet the revilements.

An example of a cable outer diameter cable 53 mm up to 54 mm for some.



And this is a M63 cable gland it takes a cable diameter 42-54 mm



But I also see in the drawing that it says 2'1/2 which would give you 50-63 mm with this one



Best Regards A

“Logic will get you from A to Z; imagination will get you everywhere.“
Albert Einstein

Yes apparently they use single core and not multicore for the motor cables