[TomL21]

My X axis drive (Viper 100) keeps blowing the 10 amp fuse as soon as input power is supplied. I had tuned the motor off the machine, Got it up and moving with Mach, connected it to the machine and tested. The fuse blew within a minute of power up. No when power is applied, the over current led flashes and the fuse pops, doesn't matter if the motor power is connected or not. Is something fried on the Viper? I don't think I did anything to cook it. If it is fried, any thoughts on if it can be fixed or not?

[Larken]

Tom, when did you buy it from me ? I had an issue in the summer with bad brownout programming which causes drives to blow when they get turned off.

What version is the firmware ?

Sometimes a bad motor (with a leaky armature) will tune fine on the bench, but when you mount it back on the machine then it gets grounded and the problem shows up.
Check with an ohm meter to see if there is continuity between the frame and armature

Larry K

[TomL21]

I bought them August 22nd. It's only one I'm having issues with. I will look at the rest tonight. How do I get the firmware version?

[TomL21]

The other two drives are version 2.7H. Safe to say the blown one is too? I can't power it up to tell.

I checked both motors I tested with and didn't get any continuity from armature to ground. These are old motors, possible something else may be wrong with them?

[Larken]

Toms encoders are Danaher Controls, Dynapar Model #E2305001538, 5 volt.

Anyone know the current draw ?

The Viper 95 (yours is not a viper 100) is limited in the encoder current (75ma max) since its a single supply board and the voltage regulator gets overloaded if the current is higher. I was origionally saying that it could be 100ma, but 75 is maximum.
I've also changed the series resistor on the V95 from 24 ohms to 100 ohms 3watt to reduce the drop across the Tip122 regulator transistor .

The Viper 200's can handle a lot more encoder current since it is a dual power supply.

Larry

[TomL21]

I found this for the E23 series encoders on the Dynapar website:

Input Power: Open Collector or Totem Pole outputs: 4.5 VDC min. to 26 VDC max. at 200 mA max.;
Line Driver: 4.5 VDC min. to 26 VDC max. at 80 mA max.

Looks like the encoder overloaded the drive?


Website for the above info:
http://www.dynapar.com/content.aspx?id=108