I have a test stand which contains a magnetizing/de-magnetizing device which is controlled by a variac. We've had repeated instances of the magger/demagger coil being left energized which of course causes it to heat up and could damage equipment or even start a fire. I want to make it impossible for this to occur again. My plan is to install an interval timer relay which will be activated by a push-button. The way it will operate is that the operator pushes a button which will energize the circuit and activate the relay's timer. The operator will then have a 30 second window in which to perform the magnetizing/demagnetizing (as required) operation. This is sufficient time and should the variac be left energized, the circuit will de-energize after 30 seconds thus eliminating the hazard. I've identified a suitable relay for this purpose.
That's all easy enough to implement but as a "nice to have" feature, I'd like to have an illuminated push-button which only illuminates while the circuit is energized for that 30 second interval. I guess I could simply tie the illumination posts of the switch to the relay output contacts but the problem is that this magger/demagger device draws up to 18 amps. If I'm not mistaken, the 18 amps would be passed through the switch and it seems that most aren't rated for this much current. If the push-button itself can handle such current, I don't believe that the LED contacts can handle that much. Does that sound correct?
So my question is, how can I make this work? Does anyone know of a switch which will be sufficient for this is there some other way I would need to do it?
Thank you for any assistance!
