Snap Amp... Supply reverse polarity

[spank]

I got my SnapAmp this week, and wired it up to test on a motor today. After getting everything wired up, I powered up my cabinet and there was a spark immediately at the DC supply terminals. I shut the power instantly and took a look. When I disconnected the mains power and repowered my Kflop/Snapamp/Kanalog, all the lights came on as they should, and the Caps by the supply input didn't seem to explode. Upon closer inspection, I had my polarity reversed on the DC input. It was a dumb mistake, that I was sure I hadn't made prior to hitting the on button... but I guess not. At any rate, before I go and try powering the unit up again with the correct polarity, is this something that definitely will fry something on the SnapAmp? Is it safe to try repowering it? The low logic side of things seems to be ok as I can it lights up properly, and I can communicate with it via KMotion.

-Spank

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[spank]

I decided to try switching the wires and repowering the mains. Doing this, no sparks. I did notice however that I couldn't see any supply voltage coming into side one of Snap Amp when viewing the Analog status screen. Switching the supply to side two, I could see that I was getting 80vdc. I'm guessing I fried something on side one. Hopefully this isn't the case. I tried tuning a DC servo from side two, but I couldn't get any motion. Nothing seemed to energize the motor. Using side two, I connected the motor + and - leads to outputs 4 and 5 (JP1 7-8). I downloaded settings to Kflop, set for DC Servo and output channel 10. The encoder is wired through Kanalog, and appears to be functioning properly (it is input 3 and set accordingly). With these settings the servos do not seem to be energized at all. Before trying to send signals to the motor, I made sure to set my peak voltage and current limits for snapamp. Am I missing something here, or is it safe to assume that the snapamp needs to be repaired?

[TomKerekes]

Hi Spank,

Sorry to hear that. Reversing motor power is likely to have caused damage.

You might try something simple by commanding a current to a PWM with a Console Screen Command such as PWMC10=100

You will need to set the peak voltage and current limits for the both sides. When you did your test did you set the current limits for both sides? Did the fault LED on SnapAmp go out?

To test the Supply Voltage measurement connect only the 16 pin ribbon cable from KFLOP to SnapAmp, then apply a Supply Volatge, then turn on KFLOP with no configuration at all. The Supply voltage should read correctly on the KMotion.exe Analog Screen. If not SnapAmp has been damaged.

If you would like us to test the board contact our support for an RMA #

Regards

[spank]

Thanks Tom,
I will try the test when I get back home later tonight. I suspect that I will need to get it repaired though.

-Spank

[spank]

Hi Tom.

I tested the Amp as you suggested, and it appears that side one is definitely no receiving supply voltage. Side two gets 80vdc as expected. I still cannot get any movement from my servo motor. I tried sending PWMC10=100 ( I actually did this before you suggested it to no avail) and nothing happens. I tried again to get some movement using the Step/Response screen, and I get nothing. I have been setting the clamping and voltage protection for both sides, and when I run the c program, the solid light does go out. Still, the amp appears to not be functioning. I will get in touch with your support and send it back. Hopefully it can be repaired easily.

-Spank

[MadTooler]

Spank,

How did this turn out? I may have a painfully similar situation.