wiring in a Water flow/ pressure sensor and E Stop

[bigforkg]

Im new to the k40 but I do have a cnc router. My question is wiring in a Water flow/ pressure sensor and E Stop are you shutting down the whole machine or ONLY the laser tube? How are you wiring them in? Can I use the laser switch on the panel?

[Tech_Marco]

In general, you wire the water sensor across to the laser power supply terminals: water protection which is "WP" and "Gnd" (common naming).

For low power laser, yes you can use a Big Red emergency to cut off power. However, for higher power rating tube like 60W (equivalent to 600W AC power) , you should never use the Emergency switch to serve as main power control. The reason is that the current handling from the switch is very low, usually below 6A. If you're running AC110V for a K40, the 35W tube (approx 350W) take 3A which is good in the limit. However, for a 60W system (eq. 600W), it take closed to 5A which is too closed to the peak current the Emergency switch can handle.

Solution: Use a solid state relay or solenoid relay. Let he relay to take care high current without causing melt down problem. I prefer to use a 25A SSR which is so easy to use and very safe. What you need is to get a control dc voltage from DC3V to 36V and wire it up in series with the Emergency switch. Once power to the SSr shut off, the SSR shut down power for the machine and the laser power supply.


Marco