Industrial 3 phase pressure washer - earth leakage.

[skatingsparks]

I'm having a "brain fart" moment..

I have 2 pretty big industrial 3 phase jet washer - one 63 amps and one 88 amps per phase (different companies/buildings)

Basically a giant water heater (with numerous heater elements) and a pump.

Water heater so needs earth leakage - both units 3 phase and earth balance load so no neutral.

Basic understanding of earth leakage is that it references to neutral - picks up imbalance between current in and current out on neutral.

The 88 amp unit I ran a 25mm SWA to an IP rated 4 pole isolator (so there is neutral in the cable) from there in 4 core Ho7 with the earth leakage at the DB.

The 63amp there is an existing supply which is a 63 amp redundant welding socket but no neutral at that point. I can still put the Earth leaked at the DB end.

I saw the 88 amp unit does have 220v inside derived from a transformer in the unit which I also saw the neutral side was connected to the earth of the unit.

Are there any specific considerations for these to situations.

Balanced loads on 3 phase earth leakage with no neutral going to the unit?

Thanks

[GCE]

I had a similar question with cold storage containers which were 3 phase compressors and no neutral
The socket outlets were 4 pin
The ELU will not trip - on questioning suppliers we found that there is a earth leakage unit designed for str 3 phase no neutral