Replacement Fuse

Weevil

I have the Duet 3 6HC. The fuse for my heater bed blew. The board is powered by a 24 power supply. What kind of fuse is that? I read in the documentation that an 18A is rare and I should use a 20A.
Is this the proper replacement:
https://www.amazon.com/40Pcs-Standard-20A-Blade-Motorcycle/dp/B0CS3W7Q94/ref=sr_1_1_sspa?crid=3A2B3BTBE893&dib=eyJ2IjoiMSJ9.yFxFLDVhm7b_hZ7-LeFwdg5gmVmYQhGbqgkgTLFdg-xuX43Z7Usvde42AVZYrxE-GzlgjQDDZP5ZmVUomNsFlAwX7emb9o8vVVn177U00c1bDaAkbwlNZViIfWWIF9z2H7O8I7TWbNneMAFrbHOUwWkVRdMVFwpjhvh9act1O1Qf5-ZjIydI-UVwhvqYD-NU3CSraZt4dMqNWUvZMGBhbFhZ5imJVDMryOjFkdprmdg.mBVX5ofXVr93RLW4OH_tDEXUVvFsC2BW9Wx4rcZ4b6E&dib_tag=se&keywords=20A%2Bblade%2Bfuse&qid=1710940300&sprefix=20a%2Bblade%2Bfuse%2Caps%2C152&sr=8-1-spons&sp_csd=d2lkZ2V0TmFtZT1zcF9hdGY&th=1

droftarts

@Weevil Yes, it's a standard ~~Car~~ mini blade fuse. Usually it is fitted with a 15A fuse, which are common enough. The absolute maximum current we recommend is 18A; to get to this, yes, you can fit a 20A fuse. However, If you bed draws more current than that, you're risking heating up connectors or possibly causing the MOSFET, that switches the bed on and off, to fail. This may cause runaway heating, melting and fire!

Ian

dc42

@Weevil @droftarts it's not a standard car blade fuse, it's a mini blade fuse. The one we fit for the bed heater is 15A.

Weevil

Thanks. I ordered.

Weevil

My heating pad is rated at 24v, 400watts which converts to 17 amps. I think I should be safe with a 20A fuse, correct?

gloomyandy

@Weevil Did you see the comments above about the dangers of running your bed with a 20A fuse fitted? Have you considered fitting some sort of external MOSFET that is better suited to handling your bed?

dc42

@Weevil if it definitely won't draw more than. 17A then it's OK to use a 20A fuse.

Weevil

@gloomyandy Yes, the hazards of using a 20A fuse with a heater that draws more than 20A. Mine draws 16.66A

gloomyandy

@Weevil Just to be clear the warning was about what might happen if your heater draws more than 18A (the absolute max rating for the board). A 20A fuse will allow that limit to be exceeded. Your call of course, but personally I'd be looking at using an external MOSFET or getting an alternative bed heater.

Weevil

It's now a moot point. The replacement fuse didn't resolve. The heater is dead in the water. I am not sure I want to put any more money into my printer.