Resext_on, the max permissible switch-on time for external braking resistor is max continuous period for current delivered to external braking resistor. After this time at the latest, there must be a "pause" inserted. During the pause, no current is delivered to the braking resistor. The purpose is to balance resistor temperature and to avoid a high rise of temperature followed by long fall (cooling during pause).
The parameter should not be greater than 10% of the resistor time constant.
On the other hand, the parameter should not be very small as it can limit the current delivery and braking dynamics for high inertia loads.

Publié pour:Schneider Electric Belgium