Lenze 8615E - Manual (Page 38)

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6 Accessories
Accessories are not included in the scope of supply.
6.1 Brake resistors
In the generator mode, e.g. when decelerating the drive, the
machine returns energy to the DC bus of the controller. If large
inertias are braked and/or short deceleration times are set, the DC
bus voltage may exceed its maximum permissible value. In the
case of overvoltage in the DC bus, the controller sets pulse inhibit
and indicates "overvoltage ". The controller cancels the pulse inhibit
once the votlage has returned to the permissible range.
To avoid overvoltage during braking, a brake chopper is used,
which switches an external brake resistor when the voltage in the
DC bus exceeds 765 V.
The absorbed energy is dissipated as heat so that the voltage in the
DC bus does not rise further.
•
The brake chopper is already included in the standard controller.
•
The suitable brake chopper is available as an option. It is
connected to the terminals BR1 and BR2
(see connecting diagram, page 26).