Fire safety shut down system using Inkbird and IceCube relay

[Eric LB]

After boning up on relays (ladder logic) I decided the @$15price was right to get a second Inkbird ( the first Inkbird controls my halogen build chamber heating lights). The safety Inkbird's sensor will be mounted just above or next to (?) the hot end Bowden tube connector and that Inkbird set to "cool" at, say 95C. It's contacts (NO) will close if the area near the Bowden Connector reaches that temp. This triggers the coil in the icecube relay which opens the relay (NC) contacts that interupts power to the printer. The printer power stays off until a (NC) "reset" switch upstream from the Inkbird and relay is opened ( or a massive fire burns up the ten amp fuse that I installed in the PIE plug power input for the relay system that I have located in the top of the printer along with the Inkbirds and IceCube).

I would gladly welcome any suggestions/ tweeks.

[Xenocrates]

Glad to hear you went ahead and learned ladder logic. As you probably know, I gave you most of the input I have on this project already. Best of luck, and hopefully a little knowledge will get you a long way with ladder logic.

[Eric LB]

I have finished my combined chamber heating system (three 50watt halogen lights controlled by Inkbird thermostat) and fire safety system( another Inkbird, dpdt 8 pin IceCube relay, reset switch and 10amp fuse). The halogen system is down stream of the relay so that if temps go too high just above the extruder cold end EVERYTHING SHUTS DOWN, power is cut to the printer and the halogen lights. I have tested both the heating system and shutdown system at loss trip temps and they are working flawlessly.

I cant thank you enough Xenocrates for motivating me to educate myself on ladder relay logic. Before your post, I was oblivious to even the terms "ladder logic" and "NC" and "NO". Getting and building this 3 D printer has brought me out of the stone age.

[Xenocrates]

Heh. So long as you're learning, you're winning. I personally learned ladder logic in a pneumatics class (at least the first time, there are some really interesting differences between pneumatic relay logic and electrical (no electricity involved in those pneumatic relays, the were all air, for those curious)). I would like to suggest you eventually draw up wiring diagrams for your printer, and possible laminate them and attach them to the inside of the upper deck. Control circuits such as the safety relay should be draw with two straigh lines down the paper, one for source and one for ground (Or live and neutral for AC control circuits which are few), and each set of systems should be on it's own level, or rung, of the ladder thus represented. This makes it much easier for anyone who gets a hold of it later to understand it, and also gives you a reference should you wonder what you're doing later.

Best of luck with it, and in all honesty, I hope you never end up needing to more than test the function of the safety systems.

[Eric LB]

I cleaned up the diagram. There are four rings. Anyone not wishing to heat an enclosure can simply eliminate the fourth rung.