Heated Bed Failure
My VC3.1 500 has been running well and had been doing some large prints. Then suddenly, it began shutting down before the print when the heated bed is turned on. I checked all electrical connections and everything wiring wise is fine and the SSR is sending 120 to the heated bed. The printer goes into the shutdown failsafe quick enough that I cant feel a noticeable temperature on the bed, so I can't tell if it is a heater problem or thermistor problem. Any thoughts?
Solution:Jump to solution
Replacing the thermal fuse worked! The bed is now heating and got through a benchy without issues. Here's the fuse I ended up putting on it: 157C, 15A. https://amzn.to/3vhviez
10PCS SF152Y SEFUSE Cutoffs Thermal Fuse 157C 157 Degree 15A 250V New
10PCS SF152Y SEFUSE Cutoffs Thermal Fuse 157C 157 Degree 15A 250V new
14 Replies
What error message, if any, do you get from Klipper?
sounds like the thermal fuse has blown.
Here's screenshot of the messagte and downloaded klipper log
That would be the message if the thermal thermal fuse has blown, I would check check it for continuity or replace it.
Which one is the thermal fuse?
that depends on your heating solution, I believe the fuse is integrated into the heating pad on some.
its the 1500W keenovo that was part of the kit
is it possible to replace the fuse? Any idea how it could have tripped? Before the errors, the printer successfully completed several 17+ hour prints with PETG at 80C.
no idea on the how for the trip or on replacing the fuse, maybe someone else here knows
No problem with replacing the fuse, I've done it at least 4 times in 10 months. It is located under the heating pad, you have to pull it out of the little pocket. I would get several spares. The fuse is crimped on (very poor design in my opinion) you will probably need new crimps or an alternate way of mounting. Fuse like this or similar: https://www.amazon.com/gp/product/B0124KPEVS/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1 BTW, I had one blow half way thru a print couple of days ago, like I said it is not the best of designs, the wires are close together, generate heat and that can blow the fuse, also it blows sometimes on start up especially when the ambient temperature is low.
5 Pcs Aupo Thermal Fuse Cutoff TF 157C 250V 10A BF157
BRAND NEW, Brand: Aupo, Quantity:5pcs
ok. A few questions to follow that then:
- Can I just solder it instead of crimping? Or solder on short wire extension and put a connector on it?
- How do I cover it back up? Like what adhesive to glue the pocket back down?
- this is 10A (assuming whats in mine is the same)... I am in US so 120V with 1500W heater ~12.5A which is more than 10A. Im guessing with running the bed hotter for the PETG, it was likely pulling more current for longer and that was probably what caused it to blow and less likely the bed went over 150C. How do I prevent this from happening again? Is there a higher current version of it? Or is there a way I can limit it in the configuration?
* I would think since I bought the 120V version of the heater that the fuse would be appropriately rated for the nominal current... wtf?
Can I just throw any thermal fuse thats rated right temperature in there? Like this one is 150C, 250V, 15A https://amzn.to/49dCmXE
or https://amzn.to/3OiFklO (many temp options for 10 and 15A)
6 Pieces TF 150C 302F Thermal Fuse cutoff ry mini micro metal 15A 2...
Package Includes 6 Pieces - Metal Thermal fuse 150C 302F 15 amp 250v Color may vary
ELCOKITEX 50Pcs Thermal Fuses 150C Degrees 15A 250V Metal Temperatu...
ELCOKITEX 50Pcs Thermal Fuses 150C Degrees 15A 250V Metal Temperature Breakers Cutoffs RY Series for Electric Pressure Cookers Multi Cooker Home Appliances Circuits Protection
The original was 157F, I would get at least that, some people here are running 189F (too much for my liking). Not a good idea to solder, as the solder may melt. You are supposed to put it back into to pocket, no glue. The fuse did what it was supposed to do, it blew when things got too hot. Correction, the temps should be in Celsius not Fahrenheit.
Alright so I finally got around to pulling the bed off the printer today. The fuse it came with was indeed only 10A. I had to order some crimp connectors for it (https://amzn.to/3Pu2ExH). Hopefully will be able to report back tomorrow once the connectors arrive.
Wirefy 100 PCS Non Insulated Butt Connectors Kit - Butt Splice Conn...
Butt splice connectors are used to lengthen, change, or repair an electrical circuit with a straight butt splice. The ends of a stripped wire are inserted into the openings on the connector. The wire ends will reach the separator inside the connector barrel and butt against each other inside the ...
Solution
Replacing the thermal fuse worked! The bed is now heating and got through a benchy without issues. Here's the fuse I ended up putting on it: 157C, 15A. https://amzn.to/3vhviez
10PCS SF152Y SEFUSE Cutoffs Thermal Fuse 157C 157 Degree 15A 250V New
10PCS SF152Y SEFUSE Cutoffs Thermal Fuse 157C 157 Degree 15A 250V new