|11-25-2006, 04:43 PM||#1|
Join Date: Oct 2006
Location: Oshawa Ont
Total Props: 0
Fusing an Electric Airplane
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I recently read somewhere that in the fine print of MAAC Insurance, electric airplanes are supposed to be equipped with a fuse.
Can anyone confirm this?
If it is true, where would the fuse go? If you put it between the battery and speed controller and had it blow due to a short or exceedance, you have isolated the battery but lost all control of the model.
If you put it between the controller and motor, you keep control of the model but have only isolated the motor.
The idea of a fuse makes some sense with some of these high amperage systems and many guys are putting battery/controller combinations together that exceed motor limits.
The other argument though is in keeping control ( even if only very temporary ) of a possible fireball.
Anyone have any comments?
|11-25-2006, 09:06 PM||#2|
RCC Pro Contributor
I am: Mike Gyger
Join Date: Jul 2005
Location: Chilliwack BC
Total Props: 0
I don't think it's necessary. I also read that in the MAAC rules, but I'm pretty sure they were refering to the old way of doing things. Basically, they used to just hook up a battery, a switch, and the motor. You would toggle the motor with the switch, (Via a servo).
Today, with a modern speed control, they will typically have some sort of overload built into it. Get a speed control that is appropiatley sized for the application, (don't drive an 8 amp motor with an 80 amp speed control), and you will be adequately protected.
I just reread the Safety Code.
This is not a requirement. It is a recommendation.
If you want to fuse it, I'd go 150% of your motor load, and put this in line between the motor and the ESC. Do not put it between the battery and the ESC unless you have a seperate battery for your receiver. Also, if using a brushless motor, I'd fuse at least 2 leads, if not all 3. This is really getting complicated though, and I don't think it will help much.
|12-14-2006, 11:11 AM||#4|
RCC Junior Contributor
I am: Roderick M.
Join Date: Sep 2002
Location: Kelowna, BC
Radio of choice:
# of RCs: 25
Feedback: 1 / 100%
Total Props: 1
A number of years ago I bought as Astro 05 geared brushless motor and check the matter of fusing with Bob Boucher of Astro Flight. His advise was that you cannot put a fuse between the motor and the ESC when using a brushless motor. The only place for a fuse, (with a brushless motor), is between the ESC and the battery. If you choose to do this, you should use a separate battery to power the radio/servos. As mentioned earlier I believe the modern ESC's provide sufficient protection for motor overload situations. I don't use fuses when I am using the BEC function of an ESC. When using a separate battery pack I fuse the + line from the battery --- I have used this fuse as an inline switch as a safe means of killing all battery power to the ESC/motor untill I am ready to fly.
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