nord NORDAC SK 200E, Руководство пользователя

Страница: 26 / 180

NORDAC SK 200E Manual
26 Subject to technical alterations BU 0200 GB
2.3 Brake resistor (BR)
During dynamic braking (frequency reduction) of a three phase motor, electrical energy is returned to the
frequency inverter. In order to avoid an overvoltage switch-off of the frequency inverter, an external brake
resistor can be used. With this, the integrated brake chopper (electronic switch) pulses the intermediate
circuit voltage (switching wave approx. 420V/720V DC, according to the mains voltage) to the brake resistor.
Here the excess energy is converted into heat.
CAUTION
The braking resistance and all other metal components can heat up to temperatures above 70°C.
When mounting, sufficient distance from neighbouring components must be maintained. When
working on the components, allow sufficient cooling time beforehand
2.3.1
Internal brake resistor SK BRI4-…
The internal brake resistor can be used if only slight, short braking phases are to be expected.
NOTE
With the use of internal resistors, the DIP switch 8 must be set to “On”. This is important in
order to activate a limitation of the peak power of the brake resistor. Otherwise, the brake
resistor may be damaged during operation.
Alternatively, a suitable power limit can also be set in P555, P556 and P557. However, this
is only effective if DIP 8 is set to the “Off” position.