Hi and
to the forum.
The temperature of the controller will depend upon the amount of current being delivered
(motor load), the length of time it is kept under this load, and the heat dissipation rate of the controller's heat sink.
If the controller is mounted on a large finned heat sink with active cooling
(Electric cooling fan) or a water cooled heat exchanger plate, it will obviously run a lot cooler under the same load than it would without any additional heat sink being fitted.
The controller may have built in temperature monitoring, which could automatically decrease the current if the controller's temperature gets too high, but you would need to check this with GM China
(sales@goldenmotor.com) to find out if it does.
Alan