Denford Software & Machines

Having taken delivery of my 17year old Compact there were a couple of issues to attend to before putting it to work. One item was that the Emergency Stop Switch was not properly installed. During its reinstatement I found that the wire connectors were only making partial contact causing spurious tripping if the switch was moved. Having made good the connections I operated the switch a few times and, as all seemed well, I fixed it back into the casing. Next morning VR could not establish connection with a warning that the mains power or the data cable may not be functioning but on inspection they seemed fine. I found a thread here that led me to suspect that I'd lost the 24V supply, so off with the back panel and locate F3 which had indeed blown (24V coming out of the transformer OK).
So my question is how could my few test operations have caused the fuse to go?
Before I can get going again I need to take delivery of replacement 6.3A fuses, but, in the meantime, are there any other steps I should take before powering up again?
Brian

If you have a look here https://www.denfordata.com/bb/viewforum.php?f=37 you should be able to find the correct diagrams for the machine. (you may have a pack of them inside the control panel, they used to put them in there).

I would put a fuse in and see what happens, if it blows again then there is an issue. If it doesn't it might just have been a 17year old fuse that had some dodgy wiring on part of it so may have had a few high short term loads (shorts) that finally popped its clogs when you fired it up this morning.

Remember in the old days light bulbs always failed when you turned them on not off. the transition from no load to a load is the straw that breaks its weakened back.

I trust you can follow a circuit diagram? It's a bit late for me to go through mine and work out which fuse it is, You should be able to disconnect the load side of things and just work your way through plugging back in until it either blows or works.

Pete

Thanks Pete,
yes I've got the RC-1 power supply diagram, so if it does blow again I can isolate the 3 functions coming off the fuse. I've ordered 5 fuses so I'll have enough to play with.
Brian

If it blows the fuse again its probably the Z axis brake & the two diodes connected across 13-15 & 15-0.

That's interesting, I've not looked at one with the Z brake how is it activated/deactivated. is it only used when the machine is not cutting or is there G code to control it?

Pete

It`s to stop the Head dropping when the Emergency Stop is pushed in.

We don`t fit it to every machine but it is activated & released by the Emergency stop relay.

Once again.. Great info Thanks Martin.