Centent 0143 Wiring Question

[jmytyk]

Hello all, thanks in advance for any help.

I know that Centent's arent Gecko's but there atleast close.

I have 3 Centent 0143's that I am having a bit of a problem getting wired. I had them working when they sitting on a table not bolted into a box. When I bolted them to a heatsink, then into a metal box, I am getting continunutiy between the power supply ground and the metal box. This isnt supposd to be that way? Unfortunatly i found all this out as i was sorting out why i was blowing fuses.

So, did I fry the drive?
What's up with the power supply ground, connecting through the power supply?
Is the wiring different from Gecko's- I thought, they were similar just an older design?

Thanks...
_Jon

[jmytyk]

to close this thread, to help someone else out. i managed to blow the MOSFET's in the drives. 1 in each drive. the bad news is, the drives were encased in epoxy, so the only way to open them up was destructively. They were shorting them self to the heatsink.

...moving on

[Mariss Freimanis]

The CN0143 is the ancient ancestor of all Geckodrives. I designed the CN0142/CN0143 (in '83) and the Geckodrives (starting in '99).

The aluminum case has always been grounded to terminal 1 (power supply ground) in all of my designs. It is standard good and proper practice for any number of reasons. It is expected as good practice the box you mount them in is grounded to your power supply ground return terminal as well.

If you blow anything in the CN0143, even a 1/4-penny resistor, you are entirely out of luck. As you pointed out, they are encapsulated in epoxy and are entirely unrepairable.

Try running them on the bench again. If they work, count yourself as lucky and straighten out your control box grounding issues.

Mariss

Mariss

[jmytyk]

Thanks Mariss,

Unfortunately, the drives don't seem to be in a usable condition- i applied a hammer and large screw driver in my troubleshooting method...

I will have to review a wiring diagram to see which grounds get connected together. I thought i had it figured out. By power supply ground, do you mean the DC (-) or the AC ground, as in the 3rd (green) prong coming out of the extension cord... ?

Then were is the shielding grounded to, if not the metal box. would this cause a ground loop (or some other term) mixing power supply ground and data ground?

In any case- you'll see my name on order for a G203V - thanks -jon