@oliof After looking at the diagram of the Duet 2 Ethernet motherboard multiple times, I cannot pinpoint where the MOSFET for E1heat is.... Would you be able to point this out for me? I should be able to replace it myself. (Apologies for such a basic question here.)

Also, is there a PWM capable IO on this motherboard you think I might be able to use? Or would this require an additional board? My SSR is rated for 3-32V DC input. I am using a Crydom D2425 which I trust is working correctly. (I am using the same SSR for the bed and it hasn't had any issues.)

Thank you so much for your recommendations!

I am using a Duet 2 Ethernet motherboard with RepRap V3.3 and currently have a hotend connected to E0heat (working properly) and a bed heater (requires 120V AC) connected to the bed heat terminal with an SSR (also working properly).

Recently, I added on a chamber heater and read the Duet Documentation for connecting a chamber heater during setup. My chamber heater is a 1000W ceramic air heater that can use 110V or 220V AC. That said, I set up the chamber heater to work with AC mains power through an SSR to the motherboard.

First, I wanted to try connecting the chamber heater to E1Heat (an extra extruder terminal) via its SSR. The duet documentation states that you can do this if your chamber heater uses the same voltage requirement as the board. The motherboard requires 24V DC, of course, and as I mentioned, the chamber heater requires 110V or 220V AC. That said, they are not the same. I knew this initially, though I wanted to test the chamber with a lower voltage input from this terminal to see if I could get it to work properly when directly connected to the board.

As a result of this test, every time I turn on the board and the chamber heater is plugged into AC mains power, the heater immediately starts heating and will not stop until it is unplugged from the mains (even though it is OFF on the interface and has not been activated). I later found that the E1Heat terminal I plugged it into from its SSR was receiving 24V no matter what mode I set (OFF, ON, or STANDBY) and the light showing that extruder heater as "ON" stays lit as well. Even when the chamber heater is not plugged into AC mains the motherboard still sends 24V to this terminal.

Finally, here's my questions on all this:

1. From all of my searching on this issue, it seems most likely that I have messed up or blown my MOSFET for this extruder terminal, E1Heat. Can anyone confirm whether it is completely blown or if it is salvageable? Could I reset the board and see if it goes back to normal?

2. Is it not possible for me to connect the chamber to the board this way? If so, what other method makes the most sense based on its requirements? I'm doing my best to try to run all my heaters on this one board....

If anyone has any recommendations at all I would really appreciate your thoughts!

@jens55 Thank you! Going to find some now

@jens55 What motherboard do you use with your heater? Or I suppose what method do you use to control it?

I have been looking at sensors to pair with my bed for temperature control. It seems that a PT1000 would pair best with the duet 2 board I have, and would easily read the temperature range I am looking for. (and there would be no need to purchase a daughterboard) However, I have heard that thermocouples (mainly type k) have been used more often in higher-temp applications.

Do you have any thoughts or recommendations in this area from your experience? Thank you again so much for your help and patience with me!

@dc42 Thank you for these notes! I do only need 180W, but I will probably stick with the AC heater I have to prevent heating issues or increased warm-up time.

@KenW Thank you so much for bringing this to my attention! I had noticed that many of them seemed counterfeit on the sites you mentioned as well.

Currently, I am sticking to looking at those recommended by Duet, namely Auber Instruments MGR-1DD80D100 or Crydom DC100D40. I'll look for these on Digikey per your recommendation, thank you!

If you come upon any other reputable suppliers please let me know!

@jens55 Thank you so much! I have done a lot of research on the framing and structure, motion system, and other factors involved, but I was very new to electronics for with heating beds. That said, I built the system with temperature effect on electronics (especially the motors) in mind from the start, so all of my electronics and wires will be outside of the heated area/enclosed chamber with the exception of the wires coming from the heated bed.

I greatly appreciate your help!

@jens55 My print bed is 152.4x152.5mm (6inx6in). So I don't think I will need more than 180W.... It is relatively small thankfully!

I appreciate your recommendation! My goal is to print with some high temp thermoplastics and have a max heated bed temp of 170C. I'll do my best to stick with the AC heater and figure out how to use it safely with a good SSR!

@deckingman Thank you for this info! I just started looking at DC bed heaters since they might pair more easily with the board and be a bit safer for beginners. Do you think there would be any issues with connecting a DC power silicone heated bed directly to the board?

It looks like there should be no issue as long as it can take 12-24V from the board... Just want to make sure I'm not missing anything.

Hi! I am building a diy 3D printer and looking to connect the following heater to my duet 2 ethernet board: https://www.mcmaster.com/35765K328/

Please note that I am very new to this process and am learning as I go!

I read through the duet documentation for connecting and configuring a bed heater, and from this information, I believe it would be best to use a DC-AC SSR for my bed heater because it is a silicone heater and requires 120 VAC, 180W, and 1.6A.

I am currently looking for good SSR options to choose from that will fit the requirements of my heated bed and work well with my duet 2 ethernet board.

I would like to find some foundational information for best methods when wiring this system or any notes on best practices. From the wiring diagram, it is clear that there is a power terminal for the bed heater, but where does the SSR fit into this configuration? Also, because my bed requires VAC do I need a DC-AC converter or will the SSR be sufficient to convert the voltage between the board and heated bed?

I would greatly appreciate any comments or sources for more information on this topic!
Thanks!