Thread: Geck 540 motor drivers??
21-09-2013 #12Visit Us: www.zappautomation.com
I did wonder if you'd managed to sort this problem or not.
One thing I never thought about on your last thread, is the shed earth good?
You could have all your grounds connected perfectly, but if the grounds aren't actually connected to anything, then they won't be doing much good. A quick and dirty way to test, is plug an RCD in, and try the test button. If the earth is bad, then it won't trip.
Even if it does test OK, and the shed doesn't have it's own ground rod, I'd still be inclined to add a ground rod.
Hi again! Yes, my workshop has a dedicated 30amp supply from the house meter with a full consumer unit and trips separate to the house.....just gone out now and tested the RCD and it works fine. Plus I am running the pc and drive electronics from a separate extension cable plugged into a different house ring main. I would be happy to add a ground rod though...anything that might get me up and running again!!
Have you tried an RCD in the shed itself?
The RCD in the house will be connected to the house earth, which the shed will also likely be earthed to, but if there is anything wrong with the earth wire to the shed, then the shed itself may not be earthed. Trying an RCD, or one of those testers with the three neon lights that plugs into a 13A socket, will tell you if the earth is actually good.
Looking at your control box wiring, the main power supply to the drives should not be daisy chained. The diagram on the Gecko site at http://www.geckodrive.com/support/st...ly-basics.html shows how they should be connected. If connecting everything to the power supply is not practical, run short wires from the power supply to a star terminal, then run the wires to the drives from there. For the star terminals, a couple suitable mounted/insulated bolts are ideal and just use ring terminals to connect the wires.
Daisy chaining the logic (5V?) supply is probably ok, but I'd personally be inclined to add an electrolytic capacitor over the power terminals of each drive to ensure the drives get as clean a power supply as possible. Do that for both the logic, and the main power supply feeds at each drive.
What actually stops working on the BOBs?
It may give us some idea as to what is causing the problem.
The Following User Says Thank You to m_c For This Useful Post:
Hi...there is a 30amp cable running from the house meter to a consumer unit in the shed. This is fitted with a main RCD and separate trip switches for the lights, shed ring main, and separate supply to the plasma cutter. The rcd in the shed works as it should. I am going to fit an earth rod as well.
The power supply to the drives is separated... not daisy chained. Two drives have a 36volt input the other has a 27 volt. I have a separate 5 volt psu... this is daisy chained to the three drives. The last thing I did before the BOB blew was to fit 4700uf caps across the main (not 5v) supply of each driver...I'm not sure if this actually killed the BOB..
I bought a spare BOB which I have just tried (without the plasma cutter) and all the drives are fine so the drivers have not blown. Looking at the new 'broken' BOB ...there is a small hole in one of the two 74HC245 chips ...a 3 state octal transceiver. How this has blown so quickly is probably the answer to my problems!! As I said....whenever I use the machine without the plasma to try out my codes and make sure of my material limits I never have a problem...only when the plasma 'fires up' and then this is intermittent...sometimes it's OK...but not very often!
I had already ordered 3 new drives from China but they wont be here for a week or two....they are HY-DIV268N-5amp microstepping drives.....not sure if any better than the ones I already have though....they are supplied with a breakout board that has a jog control fitted.
I am tempted to order the ZAPP toroidal supply (which has a 5volt tapping) and get shut of my other three psu's and the large filter unit which isn't helping. I've already removed the electrolytic caps in case they were to blame!!
I'm losing faith in ever getting this to work...I even suspect my RTech P40F plasma cutter could be the problem but just cannot afford another model at this moment.
Couple of things I see.!!
Dump the daisy chaining it's bad news.
I see several shields going to chocolate block but don't see anything leaving it or going to ground.?
Coming from the torch I see thinner wire that looks like it runs and is taped to the same wire has the limit switch.? If so then try separating has noise could be travelling from torch to switch.!!
If that mass of wires hanging on wall are stepper cables or signal cables then shift them away from those power sockets.
Generally check and tidy up the wiring connections, all those straggler wire ends are potential aerials either fit ferrules or tin the wires. Again Separate the power and signal cables.
The Following User Says Thank You to JAZZCNC For This Useful Post:
Thanks everyone for all the help....I have taken everyting on board. I have ordered a toroidal psu and will wait until I get my new drivers from China. I am going to rebuild my control box very carefully. I am even looking at a different plasma machine but it does depend on what I can get it for.
It's taken me almost 4 years to get the machine built and then build up paid work for it to do.....so I have to get it running again!!
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