Output Contactor; Supply Network; Emc Compliance; Brake Chopper - ABB ACS880 Manual

Output current [A]
2500
2000
1500
1000
500
0
0 100 200

Output contactor

To improve safety in case of a short-circuit in the drive system, it is recommended to install
an output contactor (or breaker) between the drive output and the motor. The contactor
should open in case the drive trips on a fault.
In general, because of skin effect, the current rating of the contactor at 50/60 Hz must be
derated for higher output frequencies. Consult the manufacturer of the contactor for
dimensioning information.

Supply network

An IT supply network system with a dedicated transformer is recommended.

EMC compliance

Drives with high-speed filters are always category C4 as per IEC/EN 61800-3. See
multidrive cabinets and modules electrical planning instructions (3AUA0000102324

Brake chopper

If the motor is rotating at a high speed and the AC supply is disconnected, the back-EMF
voltage generated by the motor is rectified by the zero diodes in the output stage of the
drive, and fed into the intermediate DC circuit. The peak voltage is √2 × back-EMF voltage,
so if the back-EMF voltage generated by the motor is high enough, the resulting DC voltage
can potentially damage the drive. To avoid this, the drive can be equipped with a brake
chopper and brake resistors.
For more information, see NBRA-6xx braking choppers installation and start-up guide (3AFY
58920541 [English]).
300 400 500
Planning the drive system 23
BLHF-22-7 Continuous current
BLHF-22-7 60 s overload current
BLHF-22-7 10 s overload current
600 700 800 900 1000 1100 1200
Output frequency [Hz]
ACS880
[English]).