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My ESC just blew!


(Richard) #1

@Rusty-I completed intial testing of electronics last night with everything a go. Motors were run slow a very short time in each direction (no water on bearings). Battery power (3S) was removed after the test. This morning I powered back up and after several seconds POW, the capacitor blew out on one of the ESC’s. The power leads were extremely hot, indicating an ESC internal short. Have you had a defective ESC before? Is there a warranty on the ESC?

Richard


(Richard) #2

On closer inspection, the capacitor is not breached, just bulged out a little on the end. What is notable is the 3 IC’s that apparantely overheated and melted the plastic covering (I have attached a picture of the failed ESC ). The POP I heard was very loud, not sure what component caused the noise. Hope this helps.

Richard



(Rusty) #3

Hi Richard,

Hope you had a good Christmas! That is a pretty unusual failure for the ESC. They very rarely fail and I’ve never seen three MOSFETs fail at once. Is there any chance that it might have been connected in reverse or there was any short circuit?

I saw your other post about mounting with silicone and I would definitely suggest finding a new mounting method. The MOSFETs (six little black boxes, three of which exploded) are one of the primary heat sources and silicone will insulate them very well so they can heat up a lot. We have seen failures before from someone who put several ESCs in a box and covered them in silicone for waterproofing.

The only other thing I can think of is the 5V regulator, which is officially rated for 500mA but will generate quite a bit of heat at that current. How much 5V power (if any) were you drawing from the ESC?

You can send me an email at rusty@bluerobotics.com and we can discuss replacement.

I’m sorry for the trouble and the inconvenience! Hopefully we can get the issue sorted out so it doesn’t happen again.

Best,

Rusty


(Richard) #4

Rusty,

The 3-pin connector was disconnected from the MC at the time. Plus, I don’t use the 5V from the ESC. The battery power leads were not connected in reverse. Even if they were, I would be surprised if the ESC doesn’t have reverse polarity protection. The ESC output leads were not hot, so nothing from the T100 caused this. Anyway, it has happened and we both would like to know why. We may never find out. Both ESC’s were used under the same conditions bench testing only. These tests were very brief due to precautions concerning water lubricated bearings. I’m sending you an email. Thanks for the support.

Richard


(Rusty) #5

Richard,

Okay. It doesn’t sound like you did anything wrong so we’ll be happy to replace it. We’ll discuss it through email.

For the record, this ESC (and most others) don’t have reverse voltage protection because they’d need a fairly large diode to do so.

Best,

Rusty


(Richard) #6

Thanks,

Everything is ready to go except for the ESC.

Richard


(Rusty) #7

Richard,

Alright. We’ll get that taken care of.

Also, although it probably wasn’t the source of the issue, I’m going to add some mounting information to the Basic ESC Manual Page and mention that it needs to be mounted in an area without direct insulation of the MOSFETs or other components.

If you have any other thoughts, let me know.

Best,

Rusty


(Richard) #8

@Rusty-I have discovered that I did have battery lead reversal going to the ESC! Idiot, Idiot, Idiot!!!

I had made up extensions to allow for charging the batteries while in the WTE. The battery connector was miswired. I couldn’t see it when the ESC blew, I could only see the ESC side connector which was wired correctly so I was sure a reversal was not the cause. I apologize for not discovering that sooner. I received the replacement ESC (good thing I found the problem before testing the new ESC!!!) today. I want to pay you for it so please invoice me in a manner which will allow me to pay with PayPal. Sorry for the inconvenience.

Richard


(Rusty) #9

Richard,

At least we know exactly what happened and we really appreciate your honesty in the situation! We’ll send you an email to take care of the rest.

Best,

Rusty