RAMBO 5A Fuse blew up

Hello All,

The 5A fuse that is surrounded by the Power input, LCD pins and heater inputs: F3 i believe, blew up today when I was running a print on TAZ 5 dual extruder. The other 2 fuses seem to be fine.

This happened after a few hours of printing and calibrating. Any idea how this could have happened ?

I upgraded to the dual nozzle like 5 months back. It was running fine.

If you are using 12V power, then the current draw of two hot end heaters and 4 or 5 stepper motors is likely to be between 6A and 8A depending on the heaters. So it's not surprising that the fuse blew eventually.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

Yeah. But this is a standard Power supply that came with the machine: Output 24V 16.7A . That should be good for 2 extruders and one bed right ?

I can replace the fuse, but wondering if this will happen again. Any solutions ?

Your power supply should be fine. The fuse is underrated for what you're doing however. The board may not quite be capable of what you're expecting though.

What are the hot end heater blocks you're using rated to? If they're 12V heaters running at 24V, they will draw 4x the current that they do at 12V. You might be fine most of the time if you're doing PWM, but PWM isn't a substitute for using the right components.

Edited 1 time(s). Last edit at 03/20/2016 12:21AM by Cefiar.