Pre-transformer? What's that?

Wow
To make short the long story, We bought a device and after installation the system shows us some imperfection during work (such as blinking LEDs or mis-obeying the commands). The company adviced us that our neutral conductor is the problem and we must use a pre-transformer to have a clear Zero.
I don't know what a pre-transformer is, Does he mean an stablizer or a UPS?
Can anybody Help me?

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I thought it might help you that we are powering their system with 3P+N+GND and the N is Grounded in Main transformer side ...
Sorry for insufficient info. But I am more in Electronic than the power and this Ns and Gs are not my favorite...

Hi,

What kind of device did you bought? Is it working on a three fase power supply? The power nessecary for operating that 'Device' is it also three fase? Could you be a little more specific?
Rudi

That is a testing device for steel Plates. It uses Hyd Cylinder and some servos to put a sample plate in Position and examine the standable stress for the plate.

The device Has Just One input for power in 3P, through that it gives the power to electronic and motor devices...

isolation time

It sounds like you need an isolation transformer for the electronics to get rid of common mode noise. Doesn't it have one already?
If it does check that the secondary is properly grounded.

Thomas

My guess is that the manufacture didnt install a control transformer, and was counting on tapping 115 or so from one leg to a neutral. This requies that you bring a neutral from your distribution panel to the controller panel. Your better off to install a transformer in the controller, (usually).

Plus if I understand this is a machine for doing pull test on steel so it is probably a pretty heafty hydraulic unit. I will be less expensive to use a small transformer for the controls which I feel you should always do