Use Of A Brake Resistor - Lenze i55AE125B Manual

11.5.1

Use of a brake resistor

For braking operation, optionally the brake chopper integrated in the inverter (brake transis-
tor) can be used.
NOTICE
Incorrect dimensioning of the brake resistor may result in the destruction of the integrated
brake chopper (brake transistor).
▶ Only connect a brake resistor complying in terms of performance to terminals R
the inverter.
▶ Avoiding thermal overload of the brake resistor.
Preconditions
In order that the integrated brake chopper is activated in the braking operation, one of the
following braking methods must be set in
"Brake resistor [0]"
•
"Brake resistor + RFGS [2]"
•
"Brake resistor + IMB + RFGS [4]"
•
In the default setting of 0x2541:001
in the brake operation!
Details
The brake resistor required is to be connected to terminals R
•
In 0x2541:001 (P706.01), additionally the stopping function for the deceleration ramp
•
function generator can be set when the brake resistor is controlled, in order to avoid over-
voltage disconnection in the case of lower deceleration times.
In the default setting and with a disabled inverter and an error status ("Error active"), the
•
brake chopper is switched off. This behaviour can be changed in
Example: In a DC-bus connection with several inverters, only one brake resistor is used. It
is connected to the most powerful inverter in the DC-bus connection. This inverter then
serves to change the behaviour so that inverter disable and/or an error does not cause a
switch-off of the brake chopper.
Internal protective function
The following protective function prevents the brake chopper from being switched on perma-
nently, e.g. due to too high voltages or wrong settings:
The brake chopper is switched off if it was switched on over a period of 4 s.
•
If the DC-bus voltage again falls below the voltage threshold for braking operation, the
•
brake chopper can again be switched on for maximally 4 s without interruption.
0x2541:001 (P706.01):
(P706.01), the integrated brake chopper is not activated
Additional functions
and R
B1 B2
and R of the inverter.
B1 B2
0x2541:006 (P706.06).
Brake energy management
Use of a brake resistor
of
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