M.O.V.'s

[mr_electrician]

Hello, not sure if this is a good place to post this but since I am using a LOGO I though why not! I have a minor issue when I plug my new control box intpo one of our lathes. My control box is for a lifting station that lifts raw parts to a specific height so the robot can grap it and transfer it. I am using a Logo to control the lifting logic. I am using 24vdc from the lathe as well as a couple signals fron various relays. What happens is when I connect the harding conector to the lathe it kicks out the lathe and gives a cpu fault. Only when I turn the lathe off, plug in my connector, then turn it back on is it ok. As well I can disconnect with the power on with no issues. Correct me if I am wrong but could it be that the lathe is getting some kind of surge from the logo power up when I plug this in. Would I need some kind of surge suppresion like a MOV to correct this, and if so, what size for a 24vdc/3A load. Also, would I copnnect this across the 24vdc? Thanks to all who respond!

[panic mode]

it could be few things but the first thig that comes to mind is that both seam to be powered from same 24VDC and PSU can't handle it. when you connect decond device, power supply sees first load plus inrush of the second device and if this exceeds PSU limits, voltage dips for a moment which results in lathe cpu fault. each computerized system starts boot after small delay (confirm that power is ok). so when you have everything plugged in and then apply power, lathe simply waits until PSU brings output up and there is no fault (no voltage dips during operation). try to upgrade power supply or use separate one for externa devices (those that take power through harting connector).