rx8

There are some guys at the field (electricians) that are under the
impression that they must double the max amp output of their
motor with a larger esc ie. motor max amp is 11 amps they say
use a 18 amp esc or larger. This does not make sense to me because
the esc would allow current in excess of the motor limits but they say
that in electrical work they always use larger breakers. I think that this
theory could cause a fire in a house if for example the dryer is 30 amps
and you use a 60 amp breaker you have now burned up the dryer. Can
anyone give me something I can take back to these guys to get them on
the right track and not spend money on a esc that large when the motor
at full power will only put out 8-9 amps? One of my buddies is interested
in the AXI 2212/34 on a E-flight 3D plane and find it hard to believe that
they reccommend a 8 amp esc!

Thanks,
Ron[sm=confused.gif]

smokingcrater

esc's don't limit the motor. if the motor wants/needs to draw more power then what is currently given, it will either overload or destroy the esc in the process. you ALWAYS want to have a larger esc then what you expect your max amperage draw to be, but double is overkill. 20% is fine for more cases.

Matt Kirsch

My Feedback: (21)

Exactly. An ESC is not a circuit breaker. It will gladly give its life to provide the motor with whatever current it desires, though some brands do have overcurrent protection built in. Overcurrent protection will shut the motor down if it exceeds the limitation of the ESC.

For the most part, it's up to the modeler to make sure that the current being drawn does not exceed the limitation of the ESC. Using an oversize ESC does provide for a little "wiggle room" just in case the motor draws a little more than expected.