shorted heater, track burned out

c310

Hi!

DuetWiFi i think it is 1.03 with single automotive fuse... + SmartEffector

I accidentally shorted extruder heater and track burned out...
Good news that duet is undamaged. SmartEffector - i will solder a wire to replace track...

Question - why fuse on duet did not burn out?

thanks

A Former User

@c310 said in shorted heater, track burned out:

Question - why fuse on duet did not burn out?

probably because the trace that burned was so thin (relatively) that it had a much loweer current carrying capacity than the fuse. (which makes sense if the duet has a single 15A?18A? fuse that has to protect the bed heater that can be several orders of magnitude larger than the hotend)

edit: I would consider soldering a fuse in place of the burned trace

edit2: even with a newer Duet the fuse in front of the SmartEffector would be 7.5A so the result might have been the same, as the fuse is rated for two heaters and the rest of the Duet in that case.

c310

@bearer said in shorted heater, track burned out:

edit: I would consider soldering a fuse in place of the burned trace

good idea! i will put a fuse next to Duet board... i have 24v printer with 50W heater....
50W / 24v = 2.04A

would it be ok to put self-resetting fuse with 4A current?

A Former User

@c310 said in shorted heater, track burned out:

self-resetting fuse

really depends on the type, some have a relatively high resistance which will lead to heat. look at the datasheet and P=I^2*R