HobbyKing.com New Products Flash Sale
Reply
Thread Tools
Old May 02, 2013, 11:16 AM
Registered User
United States, NC, Raleigh
Joined Jun 2011
158 Posts
Discussion
Reverse Polarity Power Distribution Board - ESC's Fried?

I bought a half-finished quad project off rcgroups classifieds, F450 quad set up with HK 30A U-BEC ESC's and Turnigy D2830 1000kv motors. The ESC's and motor's were wired up to a power distribution board when I received it. I check out the board and the ESC wiring to make sure the polarity was correct from the ESC's to board and from the board to the battery connector (Deans). I did not notice the Deans connector was soldered backwards. I tried to hook up a 3s 2200 mah 30c lipo and got sparks and smoke. Upon inspection it looks like the smoke came from the board, not the ESC's (a little of the board covering burnt off between the battery connector and first ESC on the board). However, a lot of posts I've read said the ESC's could be fried. I'd like to avoid paying $50 for new ESC's if its only the board. Does anyone know of way to check ESC's to see if they're fried? I have a voltameter but a noob with electronics. Thanks for the help.
Ceradinimp is offline Find More Posts by Ceradinimp
Reply With Quote
Sign up now
to remove ads between posts
Old May 02, 2013, 04:17 PM
Registered User
ColinNZ's Avatar
Auckland New Zealand
Joined Aug 2004
932 Posts
This is my experience with reverse polarity with a esc. My advice if in doubt bin it, it could save you crashing your model.
http://www.rcgroups.com/forums/showp...&postcount=264
ColinNZ is offline Find More Posts by ColinNZ
Reply With Quote
Old May 02, 2013, 05:44 PM
Registered User
United States, NC, Raleigh
Joined Jun 2011
158 Posts
I was afraid somebody would say that. It just seems like such a waste. Only the power distribution board was smoking, the esc's didn't seem to be affected. But, you never know. Just wondering if there is way to check to see if the thing works properly without plugging it up and hoping it doesn't fail in the middle of a flight.
Ceradinimp is offline Find More Posts by Ceradinimp
Reply With Quote
Old May 02, 2013, 07:17 PM
Senile Member
Lnagel's Avatar
Moab, Utah, USA
Joined Apr 2003
5,907 Posts
A power distribution board is nothing but fancy substitution for wires. Unfortunately, that means that the board is burned only because one or more of the ESCs shorted and pulled too much current. With any luck not all of the ESCs are ruined. The best way to check the ESCs is to disconnect them from the board and connect them directly to a battery one at a time to see whether or not each one works.

Larry
Lnagel is offline Find More Posts by Lnagel
Reply With Quote
Old May 02, 2013, 07:34 PM
Registered User
ColinNZ's Avatar
Auckland New Zealand
Joined Aug 2004
932 Posts
Yes I under stand your pain,My esc also looked fine and it still worked, but with 12v ( 3 cells) going to the rx the rx shut off while the model was in flight You could test the volts going from the esc to the rx if its 4.8v its ok if its 12v its not. Just unplug all the wires from the esc then plug in the battery ( make sure the polarity is right ) now test the volts in the wire that goes to the rx.
ColinNZ is offline Find More Posts by ColinNZ
Reply With Quote
Old May 03, 2013, 03:42 PM
Registered User
United States, NC, Raleigh
Joined Jun 2011
158 Posts
The power distribution board shorted out between the input power lead and the first ESC in the series. I think that ESC (closes to the power input on the power board) took most of the beating. I'm going to test each one and see where I stand. I've already ordered some replacements so I have piece of mind, but I hope I can salvage two or three from this batch. Thanks for the input. I really like the voltage test from the ESC to the RX. I think that's a great indicator if there is a problem (aside from them not working at all!).
Ceradinimp is offline Find More Posts by Ceradinimp
Reply With Quote
Old May 06, 2013, 08:28 AM
Registered User
United States, NC, Raleigh
Joined Jun 2011
158 Posts
Had a chance to attack this problem head on last night. Here is what I found:
- Using a multimeter I was able to voltage across different components on the board. The most important voltage check was the ESC signal/power wire to the Rx. On a well functioning 30amp ESC with built in BEC on a 11.1v 3s 1500mah 30c battery I get 5.7v going from the ESC to the Rx. I checked all the ESC's on the fried power distribution board and all were putting out the correct 5.7v. Conclusion, the BEC part of the ESC's are functioning properly.
- Second check was to see if the motors would spin up. Now that knew the ESC's wouldn't fry my Rx, I hooked each one up to my 3s batter described above and spun up the motor. All except one would work. Now I think I found my problem child.
- Lastly, I re-flashed the ESC's to make sure the micro chip wasn't fried. All of them (including my problem child) took the SimonK flash no problem.

Conclusion, all the ESC's survived except one. The problem child just won't spin the motor properly (it sort of shutters) and only gave one beep upon initiation of power over the ESC and motor system (not the typical couple of beeps to signal it's initialized). The other ESC's seemed to function fine and they were very responsive to the throttle inputs with the new SimonK firmware flash. I'm going to run the quad on these ESC and find one replacement. I'm glad I took the time to check out the ESC's without just throwing them away. Hopefully I'll get plenty hours of flight out of them.

Thanks to all the posters for your help and advise. If anyone has questions fell free to leave a comment and I'll stop by this thread and post replies.
Ceradinimp is offline Find More Posts by Ceradinimp
Reply With Quote
Old May 06, 2013, 09:45 PM
Registered User
United States, NC, Raleigh
Joined Jun 2011
158 Posts
Quick update. I realized that the ESC that I thought was fried might not be. I never calibrated the throttle. So I re-did this with the "problem" ESC and lucky, lucky it started functioning! I re-flashed the SimonK on it and now it's installed and good to go. Long story short, all my ESC's are working with correct voltage going to the Rx. I installed a power distribution board in my quad that had pre-soldered 3.5mm bullet connectors. Not everything is wired up and looking very clean an neat. Tested everything this evening and it flys! How long is another question but for right now I'm very happy that I didn't have to wait a month for Hobby King parts to arrive! Now when they do get here I'll move on to the Tricopter! Good luck with your own builds!

Just in case you want to see the final product picture is attached.
Ceradinimp is offline Find More Posts by Ceradinimp
Last edited by Ceradinimp; May 06, 2013 at 09:51 PM. Reason: grammer
Reply With Quote
Reply


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
For Sale Mikrocopter Power Distribution Board with BL V2.0 ESC cupertino FPV Equipment (FS/W) 1 May 17, 2013 09:02 AM
For Sale Power Distribution & 40Amp ESC's SimonK. squigg Aircraft - Electric - Multirotor (FS/W) 0 Apr 14, 2013 05:35 AM
Build Log The ultimate Quad power distribution board. boaterguy DIY Electronics 2 Apr 01, 2013 06:23 PM
Sold HK Power Distribution Board turbodriven Aircraft - Electric - Multirotor (FS/W) 1 Mar 29, 2013 10:14 PM
Sold Mikrokopter OKTO XL POWER DISTRIBUTION BOARD w/ ESC's Chopper Shots Aircraft - Electric - Multirotor (FS/W) 7 Mar 10, 2013 10:37 AM