Model Boat Mayhem

Technical, Techniques, Hints, and Tips => The "Black Arts!" ( Electrics & Electronics ) => Topic started by: destroyer42 on August 31, 2015, 07:00:05 pm

Title: Blown fuse
Post by: destroyer42 on August 31, 2015, 07:00:05 pm

Hi,
Anyone have an answer to a problem I hade with my Arun today, it blew a 30amp fuse twice on one motor, it has never done this before.
I'm running brushless motors Emax 850, with turborix 60amp speed controllers, each motor is fused.
Also just discovered the fuse that's blown the prop on that side, a four blade 75mm, one of the blades have broken off.
Would this cause the fuse blowing problem?

Destroyer42

Title: Re: Blown fuse
Post by: Colin Bishop on August 31, 2015, 07:02:54 pm

If the blade has broken off then possibly the prop hit something which could have stalled the motor and blown the fuse.

Colin

Title: Re: Blown fuse
Post by: chas on August 31, 2015, 08:15:04 pm

It might have bent the shaft, that could increase the drag and blow a fuse.

Title: Re: Blown fuse
Post by: malcolmfrary on September 01, 2015, 03:56:41 pm

A quick google for the motor gave this - http://www.brchobbies.co.uk/catalog/product_info.php?products_id=863
A little way down the page is a data table giving some sample power/current examples (with aero props). 
There is also this cautionary note -

Please note:
The above performance figures are provided as a guide only. The actual performance of the motor may be degraded by incorrect timing of the ESC, battery quality, temperature, unbalanced propellor, poor installation, poor wiring and electrical integrity and also inadequate cooling airflow over the ESC heatsink.
It does reinforce what Colin and Chas said.  An increase in load might well tip the current draw above what the fuse can handle causing it to blow, but that's what fuses are for.