|Forum topic by ,||posted 04-22-2015 02:02 AM||941 views||0 times favorited||10 replies|
04-22-2015 02:02 AM
Today I attempted what should have been very simple. My edgebander needs air to run, but there is no fail safe on the machine so if it runs without air it just damages the EB.
The EB is 220 single phase. The solution was very simple. I bought a pressure switch that utilizes NC and NO when air pressure is applied. There is a setting range that I set at around 40 psi, so when it detects 40 psi it sends a 110v to my 220v contactor which has a 110 coil, then the contactor allows 220 to pass through to my machine.
So my issue is this. I have really no idea how to wire the switch and I fear I may have burned the 70.00 switch out in my failed attempts.
The switch has a ground terminal, a Common terminal, a NC “nominally closed” terminal and a NO “nominally open” terminal. So coming from my power source, I have a hot, common or neutral, and a ground. I only had 1 terminal for the common and one terminal for the ground. I thought I needed the common to carry through to the coil and the ground to carry through and ground out with the contactor. But with just one terminal for ground and one for common, I just combine 2 wires on each of those terminals, basically 2 neutrals on the common terminal, 2 grounds on the ground. This allowed me to bring a ground and neutral to the contactor/coil.
Then I brought the live hot wire to the NC terminal and then connected and black wire from NO to the coil. I also brought the white wire that I had connected to the common on the switch down to the coil.
Well it never worked. In fact I tripped my breaker. Thinking that I had the black wires wrong, I swapped them. That Was much worse as the pressure switch sparkled for a quick second before I unplugged it. Might have just wasted 70.00. Chalk that money up to education.
Maybe someone has some knowledge about this. I have wired a lot of machines, single and 3 phase, have wired contactors, done my fair share, but this little 110 switch has me stumped.