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HV enclosed with a PLC

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I've been asked, by my company to build an automated Die electric tester to be sent to China. There are four tests; two are Die electric, which entails applying 2.5KV to a motor for 1 sec. I have 8 other stations working now; the difference is they are all controlled by one PLC in a separate main panel. I am trying to keep the station enclosure as small as possible, and having the PLC and contactors/relays in one enclosure. My concern is whether the 2.5KV wires may affect the PLC. Obviously my control wiring will be shielded and routed away from the HV wires, but it's the PLC in general I have concern for. I called Tech support and once they heard 2.5KV they started back pedaling and telling me to call my local AHJ, since once you get over 1KV it’s a whole new ball game. (insert 'Shrug' icon Anybody have any experience with HV enclosed with a PLC? Off note, I've tried to post this three times now, when I go to post it I get page cannot be found. If this time it works it could be because I did not encounter a run time error, by not inserting an icon?
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I've never worked with 2.5kv, but I wouldn't do it simply for servicing reasons. There are times when it is necessary to open the cabinet to access the PLC with the power turned on, for starters, when you decide to load the program the first time.

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The 2.5KV is only present for 2 - 1 sec pulses during testing. This is controlled by the PLC. The Die electric tester which provides the 2.5KV is separate, but its output wires go into the cabinet. I am going to interlock the door to halt the PLC when open. This way if the PLC is not running it cannot tell the Die electric tester to test, so there should be no chance of encoutering the 2.5KV with the door open.
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The safer way would be to break the signal from the PLC to the contactor that passes the 2.5KV signal and leave the PLC running.
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Good point thanks for the tip. here's a link to the die electric tester I'll be using 3605D

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I've got a similiar application where a PLC 5 is controlling an air static charge unit. Voltage range is 1.1 to 2.5 KV in pulses. Original design engineer wanted the HV unit in the same enclosure as the PLC 5. I prevailed and we added a 6 by 10 box to house the unit and provide a ground plane of isolation between PLC 5 and HV. Later learned that others thast have not done this had some unexplained issues which we have not had.
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That hypot unit has interlock contacts that can be incorporated into your safety circuits for additional personnel protection.
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I have used this same unit in the same enclosure as the PLC, but it was a huge cabinet and they were far apart. They best for me has been a separate enclosure close to the unit to be tested for the same reasons stated above. Also, that way the lead length form the hipot to the unit to be tested is short, this is important for the continuity test. Don't forget to use contactors with contacts having higher voltage ratings than 600V. Also, "Die electric' is spelled correctly as "Dielectric". Edited by GerryM
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Thanks for all the replies and advice. I going to go back and rethink the enclosure part.

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maybe even put it in a small enclosure that is still inside main cabinet...

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