Blown fuse

[milton]

I have a PRS Alpha bot that was working fine the last time I used it, When I turned it on a few day ago I got the error message to reset drivers. After running through checks of the remote stop/reset switch and wiring to the control board terminals, aux, and contactors I find that the 3A fuse is open. Upon replacing the 3A fuse it immediately blew again. I can not visually see a short anywhere and am at a loss, has anyone else had a similar problem, and if so, how did you solve it? thanks

[dlcw]

I once had one of the 20amp slow-blow line voltage fuses pop when I turned the machine on. Took me 2 hours to find a local source of the fuse (Grainger) and then 1.5 hours round-trip drive time to go get it. But I was in the middle of a customers job and could afford the down time. Replaced the fuse and it has never happened again. Shopbot Tech Support said it was just a fluke. Your problem, however, is more involved and you should systematically troubleshoot it as outlined below.

Which 3 amp fuse is blowing? If your machine came with electrical diagrams (mine did) they should show what is downstream of the fuse.

The solution for solving a blowing fuse is to disconnect all the downstream loads. Make sure you have a couple of spare fuses on hand. Then one by one connect the loads back into the circuit until the fuse blows again. At that point you have your culprit.

Don
www.dlwoodworks.com (http://www.dlwoodworks.com)

[milton]

Don, thanks for your reply, I don't know why my fuse blew in the first place. However, everything is working fine now.