3 -Phase Transformer

[DannyTee]

I need to buy a transformer to install industrial equipment in Cape Town, and I'm confused as to the actual voltage delivered (400V or 415V). This equipment will also have some 120 V peripherals which I can power from phase to neutral on the secondary
Should I get a 400V to 220V or 415V to 208V ?What primary voltage should I consider?

[AndyD]

I'm a bit confused, is this American voltages you require? What is the supply requirement stated on the equipment? Is a neutral required? What is the supply that's available at the customer in Cape Town?

[DannyTee]

Thank you for your reply. The equipment requires 120 V as well as 208 V. I just need to know what 3-phase voltages are available in Cape Town so I can pick the correct transformer. Is it 400 V, 415 V, 380 V?
From the secondary (208 V) I can derive 120 V from the neutral.

[Justloadit]

Just bear in mind, if there are motors on this equipment, they rely on 60Hz to get the 1800/3600RPM, and you will be supplying 50Hz which will give you 1500/3000RPM, so the gear box ratios, if there are any may arise to unexpected operational RPMs. The motors will also run hotter, because of the frequency changing the motor inductive reactance.

One way around this may be to use a suitably rated 3 phase speed drive with a fixed 60Hz setting, driving your 3 phase transformer.

[AndyD]

The voltages vary a little depending on the premises but generally a 380/400 volt transformer primary would be suitable.