Upgrading Ender 5 Stock HotBed to Keenovo for higher bed temps

PCNoobNeedsMajorHelp

Hey...It's been a while. You originally helped me in this post: HELP! Duet 2 WiFi Configuration and DWC Upload???. After a very busy year I'm finally ready to install my Keenovo Heated bed upgrade. I think I got the wrong heated bed though. I have a 24v 350w Keenovo, and I have a 24v 350w power supply as well as an SSR. I was reading up on the stock heated bed for the Ender 5 and it's a 24v 350w bed as well (facepalm). I'm realizing now that I should have gotten a 110v 500w heated pad for higher temperatures for my bed plate where I would be pulling power from the Mains on my PSU rather than the 24 volts it supplies to the rest of the Duet. Am I correct in my thinking?

Thanks in advance for any guidance

RogerPodacter

@PCNoobNeedsMajorHelp yes you're idea is pretty much correct. you did not need another 24V 350 watt bed. a much better option would be to switch to a 110VAC mains powered bed which pulls directly from the mains power. and use a SSR (solid state relay) to break the hot line of the AC power going into the bed. control the SSR from the Duet mainboard.

dc42

@PCNoobNeedsMajorHelp as @RogerPodacter says. Make sure that the SSR you choose is suitable for the task, i.e. intended for switching AC mains at a current somewhat higher than your bed heater will draw. A 110V 500W bed heater will draw a little under 5A, so to avoid needing a heatsink for the SSR I suggest you choose a 20A or 25A SSR.

For safety, ground the bed plate. If the printer has a moving bed, be sure to use cable strain relief at both ends of the bed heater cable.

PCNoobNeedsMajorHelp

@dc42

Thank you so much @RogerPodacter and @dc42!!!

PCNoobNeedsMajorHelp

@dc42 I found this SSR amongst my things and was wondering if I could use this? If it's better for the bed to use the 25DA I'll get that instead.

dc42

@PCNoobNeedsMajorHelp that SSR should be good for switching an AC mains voltage bed heater.