GT1655-VTBD GOT1000

[WebbyNY 0]

Good Afternoon,

Our GOT1000 HMI was wired incorrectly when the vendor installed them. +24V was on ground and ground to +24V post. Everything was working fine until our Ionization system was being tested/calibrated with a 1000V charge plate placed in the tool. Then the GOT1000 HMI display went blank and no indication lights were lite on the front. I swapped the wires and the HMI works fine now. It's understandable that it faulted when the ION systems were being checked due to the polarity problem caused by the wrong wiring.

The question I have for anyone who might know is, why was the GOT1000 HMI working at all with the wiring wrong like is was?

Thanks,

Webby

 

Edited 15 Apr 2016 by WebbyNY

[Luke.S 8]

The HMI probably has a diode or transistor for reverse polarity protection so unless there was 24VDC +\- 20% on the earth wire it should not have worked. It's hard to say what happened without the diagram of the full circuit.

Is the ioniser also powered by the same 24V PSU? Is the PSU output floating (neither of the terminals connected to earth)?