What danger do you envisage might occur?

One thing to check is whether the equipment manufacturer has a specific overcurrent protective device rating (some German machines, for example, specify 25 A, which can be tricky in the UK.

And of course, if using a socket-outlet rated up to 32 A, is the outlet RCD protected in line with Regulation 411.3.3?

Thank you for the note about specific over current protective device rating.

I was wondering if there would be a danger associated with the loads being unbalanced for the 3 phase breaker supplying the socket.

That can be a rub ... in our machineshop, all the CNCs machines were connected thru 32A TPN ceeforms. This made changes easy & isolation quick and obvious. When the space was refurbished we had to remove & hardwire because of the RCD rule - try getting a 30mA RCD to hold with a CNC that contains several VFDs

As others have said, its fine. If the RCD thing is a problem and there is no local appetite for documented deviations then one can sidestep it by using a 63A socket on a supply limited by 25A MCB or whatever. Not perhaps the intention of the regs and a bit of a waste of space but not a fail either.

If you have lots of 3 phase plugs with single phase loads, it is helpful to vary the phases around so loads are not  all on phase 1.. . If you like to know which phase then a stripe of tape of the phase colour on the plug serves as a reminder.

Also in the world of temporary wiring,  3 phase plugs with 3 tails emerging each with a single phase socket or strip of sockets is a common thing, although the glanding no longer meets the IP 44.

Mike

As others have said, its fine. If the RCD thing is a problem and there is no local appetite for documented deviations then one can sidestep it by using a 63A socket on a supply limited by 25A MCB or whatever. Not perhaps the intention of the regs and a bit of a waste of space but not a fail either.

If you have lots of 3 phase plugs with single phase loads, it is helpful to vary the phases around so loads are not  all on phase 1.. . If you like to know which phase then a stripe of tape of the phase colour on the plug serves as a reminder.

Also in the world of temporary wiring,  3 phase plugs with 3 tails emerging each with a single phase socket or strip of sockets is a common thing, although the glanding no longer meets the IP 44.

Mike