RC-Monster Forums - Blue smoking MMM

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- - Blue smoking MMM (https://www.rc-monster.com/forum/showthread.php?t=29593)

Quote:

Originally Posted by BrianG (Post 401913)

Theory:

Poor connection on the EC5 connector which created resistance. That resistance created a voltage drop when large currents flowed which then caused lots of heat to melt the solder. That same resistance appeared to the ESC as a poor quality battery (high internal R) which increased the amount of ripple currents which stressed the caps too much and heated them up as well.

The blue stuff on the heatsink was from the explosion of an unfortunate nearby Smurf. Sad really, but they should know better.

I agree whole heartily, go with a stronger connector in the future. You need a connector that can actually handle more than 70 amps continuous. The failure of the capacitors is a tail-tale indication of ripple voltage, leading to damage of the capacitors. It may have been related to inadequate batteries; but if you were running 30C+ continuous then it shouldn't have been a problem. It is highly recommended to upgrade to Dean's Ultra Plugs, Traxxas Power Connectors or 5.5mm or 6.6mm bullets; something rated for equal to or more than 70 amps continuous.

We are recommending going with a battery with a 150 amp or higher continuous discharge (IE 5000mAH @ 30C continuous). Anything less could potentially lead to an ESC failure due to ripple voltage. But a strong battery pack is useless without an appropriate connector.

Thomas Porfert
Tech Support
Castle Creations

A stronger connector? Aren't EC5 connectors rated for 120amp continuous?

Quote:

Originally Posted by drkdgglr (Post 402052)

A stronger connector? Aren't EC5 connectors rated for 120amp continuous?

Yes they are. He might of have confused them with the EC3 rating.

isent those rated for alot higher amps than original deans(lower resistance)?

Also looks like you might have soldered a BEC directly to the board and also shorted the switch directly on the board.

Both of those things "normally" would invalidate any warranty.

EC5s are huge connectors, much larger than deans & make a really nice, solid connection- I'd wager it's the bizarre setup or a cold solder joint rather than the connectors themselves; I run EC5s and have no complaints..

A poor joint, loose contact, or dirty contacts is what I was thinking when I wrote my original post. The connectors themselves seem quite robust.

Quote:

Originally Posted by Thomas Porfert (Post 402003)

EC5 are much better than Deans etc.
Also I am using high quality Hyperion 4200 mAh 45C lipo.
Please let me know about the warranty.
Thanks.

The EC5's are rated at 120A continuous amps when used with a 10awg wire and basically are 5mm bullets in a plastic case.

http://www.e-fliterc.com/Products/De...odID=EFLAEC502

A few other ratings can be found here: http://www.rchelicopterfun.com/rc-lipo-batteries.html

Of course I can't confirm or deny any of these ratings. I have to believe what I've read in several forum posts and what the online stores specify. I've never seen the EC5 rated higher or lower than 120A.

Well well I have no luck!
The motor is still working with my spare MMM ESC.
So I thought let's try on the broken MMM ESC, to bad the motor is now smoked:gasp: Hmmm I will it send for the non warranty repair. Luckely I've another nice CC 2200KV motor:-)