Mk2 Power Supply max rated temperature?
I have my MK2 in an enclosure and it gets quite hot inside there. The PSU case gets almost too hot to touch after ~1 hour of printing.
I know it would be best to route the power supply out, but out of curiosity.. what is the power supply rated for on temperature? Can it handle a constant 80c?
Re: Mk2 Power Supply max rated temperature?
I don't know the max operating temperature of the PSU, as this will depend on the components and the PCB material. I can't quite tell what the PCB is made of without opening it, but it looks like either FR-1, FR-2 or a composite material, either CEM-1 or CEM-3. FR-2 should not be operated much above 100C anyway, FR-1 a little higher at 120-130C ish. CEM 1 and CEM-3 have a TG between 60 to 90 and 125C (glass transitional temperature where it starts to become soft). So you are close to if not past design limits.
As for the components, things like electrolytic capacitors generally have a temperature rating of about 85C, though some high temperature ones are rated up to 125C. Again I cant tell without opening. Its likely it will be the standard 85C given the board material. Running at the temperatures you are, at the best you are shortening the life of the caps and they will likely dry out and fail much sooner than expected
I very much doubt that it was designed to operate at those temperatures anyway, as there is only passive cooling with a few air vents, so not very much cooling is taking place in your case, so may well be hotter inside the PSU.
In summary, it is probably best if you move the PSU outside of the encolsure, even to increase the life of the components, rather than any immediate danger, though you are running the risk of caps exploding, without adequate cooling.
Re: Mk2 Power Supply max rated temperature?
Thanks for the info. I'll move it out. I ordered some male and female dc connectors so i can still remove the printer freely. Until then, I'll just print with the door open.
Re: Mk2 Power Supply max rated temperature?
I did not move the PSU out of the enclosure.
I figure it is better to move the heat out of the PSU, and into the enclosure. Free heat!
I have added a near silent fan to the PSU so now it helps to keep the enclosure warm, and I think the PSU might be cooler with a fan inside the enclosure, than outside of the enclosure without a fan.
This might be different for better insulated enclosures than the plastic boxes I use.
There is an unused 12V DC output under the black plastic cover in the PSU. I connected 2 cables to it and drilled a hole to let them out, then hot-glued screw-terminals to the outside of the PSU. Now I can quickly add more 12V devices if I need to.
The LCD is now outside the box and there is a LED lamp in the box with the light switch on the outside.
A filament box full of silica gel connects via teflon tubing to the extruder so the filament stays dry.
Currently printing an addition to the LCD box to protect it a bit better on the workbench.
Re: Mk2 Power Supply max rated temperature?
So how hot to the touch does the PSU get after printing for an hour or so?
My enclosure gets toasty warm inside from the heatbed running at 90c for PETG prints. Im not sure if adding a fan will adequately cool it as really warm air will be circulating through it.