dc amps vs ac amps

[Robin Hewitt]

I would argue that fuses are essential. If they 'go wrong' and are correctly sized then its a sign there is a problem somewhere... better to blow a fuse than fry a driver...

If the fuse goes pop because the driver has fried, you are going to buy a new driver anyway. They are so cheap they aren't worth repairing.

If a fuse goes pop for no good reason, the part you are cutting becomes junk PDQ. Then the cutting tool ploughs into a holding clamp, the bed dances a jig and it can get really expensive really quickly.

You don't want to end up using both hands to stall it while trying to switch it off with your foot :D

[Lee Roberts]

If the fuse goes pop because the driver has fried, you are going to buy a new driver anyway. They are so cheap they aren't worth repairing.

If a fuse goes pop for no good reason, the part you are cutting becomes junk PDQ. Then the cutting tool ploughs into a holding clamp, the bed dances a jig and it can get really expensive really quickly.

You don't want to end up using both hands to stall it while trying to switch it off with your foot :D

If the fuse gos "pop" then the driver stops as dose the motor as dose the axis in question ?, isnt the fuse there to protect the driver from becoming fried?

[irving2008]

If the fuse gos "pop" then the driver stops as dose the motor as dose the axis in question ?, isnt the fuse there to protect the driver from becoming fried?

I think what Robin is implying is that the fuse wont blow as fast as the driver could fry and that's certainly true for certain situations but if you short the motor wiring by dropping a screwdriver on it or the motor overheats and internally shorts a turn the fuse will still probably blow before the driver's MOSFET fails cos of thermal runaway unless it is very tightly spec'd...