High neutral earth reading

[Thys LOW Elektries]

Good day

We are upgrading a 3phase installation for one of our local schools, the building was wired early 60's. A 3 phase, 4core 50mm swa cable comes into the kitchen without an earth wire?! The neutral - Earth reading is 1.78 volts and the earth wire tingles when you touch it! Everything was ripped out and the whole building rewired.
My question now is, do I need to have an earth wire connected to the building if the db passes all the tests?

I personally feel an earth wire is always a good thing to have, irrespective of the test results but my employer feels different about it..
Please advise

Greetings
Thys
Orania

[markthespark]

Does the cable terminate in an oosterzee box or at the DB? It should be fitted with an earth tag. You can also consider knocking in an earth spike.

[Dave A]

Do you have loop test results?

[markthespark]

A lot of the time the earth conductor is run separately and most times these get stolen.

[Derlyn]

A lot of the time the earth conductor is run separately and most times these get stolen.

Don't think cable theft is a problem in Orania.

[Thys LOW Elektries]

The cable was not stolen, neither the tools or supplies I left overnight in the unlocked kitchen building just to cancel that as possible cause.
By the way, the old part of the town is wired via the TN-S concept, I think the neutral-earth link had been removed somewhere and now runs on a TN system
The school setup is as follows:
Electricity come to the school grounds via overhead cable, 5 wires, and is terminated in a huge pole mounted orange kiosk, originally grey. The orange kiosk have an green and gold earth wire going into the ground, presumably to a earth peg. From here six swa cables go to the various buildings. No other earth wires exit the kiosk. The db in the kitchen get its electricity directly from this kiosk, the swa cable comes into the db with no earth and is terminated in the main db. The earth comes from anther sub kiosk with no earth wire??! going into the kiosk and the neutral and earth is also not bonded anywhere.
Building was without electricity the whole day since I was working on the DB.
Will do the loop test tomorrow and post the results here. Will also test at various times to see if there is any power fluctuation, if any.

[Thys LOW Elektries]

Drumroll please, the loop test results are in. Red phase, 0.57 Ohms and 415.8 Amps. Yellow phase, 0.52 Ohms and 317.6 Amps. Blue phase, 0.45 Ohms and 489.1A
Main breaker outside = 3pole 63A.
Volts Red 230 volts Yellow 229 Volts Blue 236 Volts
Max Z loop calculated, red 1.857 Ohms Yellow 1.817 Ohms Blue 1.873 Ohms
Isc calculated, red 0.303 kA yellow 0.272 kA Blue 0.327 kA
Hope this helps
Greatings