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View Full Version : Warning: Fuse your ESC or it could become toast !


Eggvoel
10-09-2005, 01:15 PM
My FMA Direct Super20 ESC is now Toast! I've been having motor problems, (see other threads) and the last time I flew the motor quit after landing. I noticed after it cooled off it would start again. Been sitting in my shop for a week or so waiting for new motors. Thought I would try the motor to see how much power it was putting out. Was holding the plane in my hand, advanced the throttle and it felt quite strong for a few seconds and then quit. I backed off the throttle and advanced it again and nothing. But, a second later I heard something cooking and see smoke coming out the the fuselage! Disconnected the battery, but too late, the ESC was fried.
In the installation instructions an option was to put an inline fuse between the ESC and the Motor, which I hadn't done. Well, I have now on my other one.
Instead of a bulky inline automotive fuse holder, I wonder if wiring direct one of those small fuses that just clip in would work? Larry

debhicks
10-09-2005, 01:52 PM
I think the weight would be a factor. How about a small circut breaker? Surely with the way electronics are getting smaller there is a micro circut breaker. I will check into my electronic distributors and see what I can come up with. Be next week, but someone here may already know.

Just a thought.

hoppy
10-09-2005, 02:02 PM
That is a rare problem.... most quality ESC's have built in over current protection to stop that from happening.
See Castle Creations and JETI controllers.
The CoolRunning ESC's have Thermal Shutdown Protection.

Does the FMA have either?

(Sounds like your motor was drawing well over the normal currrent.)

Eggvoel
10-10-2005, 01:26 PM
The optional 20A fuse is the protection. Must have been a direct short in the motor. Rare I guess, but it happened. Will look into that feature on my next purchase.
Thanks Debbie. A minnie breaker might work, but it would have to be able to carry the 20A max load of the ESC. I'm just using a GWS350/C so not pulling anywheres near that I don't believe. Larry

willyb
10-10-2005, 02:09 PM
I found out another thing you never want to do. I had a small Ministick by Radical R/C that didn't have a landing gear. I had a Plantico DSP rec-esc combination in it, 10 amps on the esc side. I put it on the ground, and did a range check. I got out to my normal cutoff distance and I saw smoke from the plane. Apparently the borderline transmitter signal triggered the motor, the propellor couldn't turn, and that was it for the esc!

Bill

jonnyjetprop
10-10-2005, 04:50 PM
It used to be common to put a fuse between the esc and the motor on brushed motors. I used the blade style myself. Never put it between the battery and the esc if you are using a bec. Blowing the fuse then leads to bigger problems.

John

EpoweredRc
10-10-2005, 06:13 PM
When we ran brushed set up they always had fuses for them but the fuse was between the motor and the esc,you cant do this with brushless ones cause they have 3 wires and even if you had a fuse on each of the 3 wires if one blew the other would still work the motor and burn it up. You could only put a fuse between the esc and the Battery and if you blew a fuse then ,it would cause you to crash cause you would lose your radio also,Unless you was running a separate battery pack for the receiver.

jrb
10-10-2005, 06:27 PM
Here’ how I prefer to do it on my lots of watts planes; several can be found in my gallery: http://www.rcgroups.com/gallery/showgallery.php?cat=500&ppuser=497 .

Use either a fuse or shorting plug; I fly a 40amp fuse with 40Amp ESC using its BEC for a 33amp set-up.

The loop of 14ga wire is used as a shunt that allows amps to be measured w/o breaking into wiring; i.e. after swapping a prop at the field.

EpoweredRc
10-10-2005, 07:10 PM
Here’ how I prefer to do it on my lots of watts planes; several can be found in my gallery: http://www.rcgroups.com/gallery/showgallery.php?cat=500&ppuser=497 .

Use either a fuse or shorting plug; I fly a 40amp fuse with 40Amp ESC using its BEC for a 33amp set-up.

The loop of 14ga wire is used as a shunt that allows amps to be measured w/o breaking into wiring; i.e. after swapping a prop at the field.

I cant clearly see that print out of what you got,could you make the picture bigger? or just it the same size as the rest? i am trying to figure out how your running a off on switch on that set up,on and off switches cant handle power runing though it.

Jessum Dumguy
10-10-2005, 07:15 PM
Only his BEC is switched, The ESC on down to the motor is fused.

Jessum

jrb
10-10-2005, 07:15 PM
There is no switch.

Pluging in the fuse/shorting link makes up the the battery connection.

Bob_CO
10-10-2005, 07:16 PM
I cant clearly see that print out of what you got,could you make the picture bigger? or just it the same size as the rest? i am trying to figure out how your running a off on switch on that set up,on and off switches cant handle power runing though it.

His on/off switch only turns off the BEC. The fuse disconnects the ESC.

Nice setup btw jrb.

jrb
10-10-2005, 07:23 PM
With a UBEC you can see that I can turn on the RX w/o powering up the ESC/motor; for i.e. contol checks.

For ESC w/BEC just ignore the UBEC portion of the drawing; use a shorting plug or fuse, your choice.

Fues holder is from Sermos and can be had from New Creations, SR, etc. The 40amp fuse is from NAPA Auto Parts.

For shorting plug use 12ga solid instead of 14 for shunt.

EpoweredRc
10-10-2005, 07:32 PM
With a UBEC you can see that I can turn on the RX w/o powering up the ESC/motor; for i.e. contol checks.

For ESC w/BEC just ignore the UBEC portion of the drawing; use a shorting plug or fuse, your choice.

Fues holder is from Sermos and can be had from New Creations, SR, etc. The 40amp fuse is from NAPA Auto Parts.

For shorting plug use 12ga solid instead of 14 for shunt.

Alright I understand how you have it now,your running a UBEC. Not a regular ESC.
As i just posted in another post I myself with my foamies have just on half the red of a sermos behind the main power plug for easy hook up and disconnect of the Battery power.

cyclops2
12-18-2005, 03:56 PM
A fuse is always required in all equipment!!!!!
Especially in the LIPO batteries being forced to supply power to a shorted ESC or a ESC that is full on because of a short in the motor or wiring.
Would you rather have a LIPO pack catch fire at 100' up in the air over dry fields and crash? Now you have a rageing fire in the plane and it will come down out of control shortly.
Far better to open the fuse since you have a condition you can do nothing about on the ground.
Turn the transmitter off- Grab a fire extingusher and get to the plane fast.
Hope the plastic is not punctured by the crash.
That is the reality of flying a LIPO pack

Rugar
12-19-2005, 01:00 AM
A fuse is always required in all equipment!!!!!
Especially in the LIPO batteries being forced to supply power to a shorted ESC or a ESC that is full on because of a short in the motor or wiring.
Would you rather have a LIPO pack catch fire at 100' up in the air over dry fields and crash? Now you have a rageing fire in the plane and it will come down out of control shortly.
Far better to open the fuse since you have a condition you can do nothing about on the ground.
Turn the transmitter off- Grab a fire extingusher and get to the plane fast.
Hope the plastic is not punctured by the crash.
That is the reality of flying a LIPO pack

:rolleyes:

cyclops2
12-19-2005, 01:17 AM
Good example for a fuse. I was pushing to finish the drive in the PT boat. I had everything ready for a full power bench test. Go to connect the last battery cableto the deep cycle battery and I heare a weak tink. Now what. Tap the post again. another tink. You simple jerk! you have reversed the leads and the circuit breaker and the Novak Super Rooster are trying to tell me I screwed up Royaly.
Nothing was damaged except my feelings.
THAT is why a fuse is needed. You never know.:o