Burgerman wrote:Ohms law says that the:
Resistance (R) = 34.3 ohm (Ω) so
Current (I) = 0.7 ampere (A)
So you can measure and test.
These coils last.. Be aware that a 24V coil is not suppose to be fed at 24V all time. The controller should feed it 24V for less than a second , and switches to 12V immediately afterwards.
In the 3 scooters I received this month. And yesterday another one appeared!!! All with the same problem Electromagnetic brake burnt out
Burgerman wrote:May be caused by water or corrosion causing insulation break down.
TRY operating one at 10V and see if it FULLY releases and doesent fail or drag. If so, set the controller to 12V brake.
woodygb wrote:Your amps draw shows the problem.
Calculations from your readings give us ...assuming that I have done it all correctly.
2.1 Amps @ 13v = 6.2 Ohms and 27.3 WATTS .
5.4 Amps @ 25.9v = 4.8 ohms and 139.86 WATTS !!!! At this wattage your coil is a heater and will cook / melt.
I cannot find any programmer settings that allow a different voltage to be selected for the Rhino2.
Solution ... buy a 6 - 7 ohm high wattage resistor ... say 30 watts plus ... and wire it in series with your brake coil.
ex-Gooserider wrote:As mentioned, the brakes getting fed the wrong voltage can cause them to overheat and melt if they get excess current. If they don't get enough voltage, the brake may not release 100% and the friction drag from the brake not releasing fully will generate enough heat to damage both the brake AND the motor.
Note that the brake is ONLY intended as a 'parking brake' to keep the motor from turning (back-driving) when there is no power AND the scooter is not moving. It should release any time there is power to the motor, and only engage when the scooter is stopped and not getting power. (slowing and stopping is done with regenerative braking by the motor, NOT the brake!) The motor is more than strong enough to over-ride the brake, just like driving in your car with the parking brake on...
Another possible source of problems is if the brake is not fully releasing, possibly because of corrosion in the moving bits, or on the brake disk, or if the disk is warped, etc... Again this generates heat, and eventual failure...
ex-Gooserider
Burgerman wrote:Nonsense? Yes. Low battery voltage means less current.
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