Lenze 6034 Brake chopper - Manual (Page 13)

11
5. Operation
•
It is absolutely necessary to check the connection of the
terminals +U
G
and -U
G.
Incorrect connection may cause
destruction of the brake chopper and the frequency inverter.
•
In case of mains overvoltage the brake chopper may be
activated. When using resistors without overload protection the
resistor may be destroyed. Therefore, only resistors equipped
with integrated or external temperature monitoring must be
fitted.
•
All brake resistors recommended by Lenze are equipped with
an integrated temperature monitoring.
•
Due to the application of the brake chopper, the inverter exactly
follows the programmed deceleration time. However, if the
feedback power exceeds the peak power of the assigned brake
resistor, the inverter will be inhibited and will display
"Overvoltage". This results in an uncontrolled prolongation of
the deceleration time. To overcome this problem, you must
either prolong the Tif time or, if possible, select a lower-value
brake resistor.
•
LED ON (yellow) indicates the release of the brake chopper.
5.1. Parallel connection of brake choppers
With high brake powers it may be necessary to reduce the brake
resistance to the minimum permissible value (see table page 7). If
this is not enough, two brake choppers can be connected to double
the peak power. In this case, please note the following:
•
Each brake chopper must be separately connected to +U
G
and
-U G of the frequency inverter.
•
Each brake chopper must be connected to a separate brake
resistor (terminals RB1 and RB2).
•
The thermostats of the brake resistors (break contacts) must be
connected in series.
•
The lowest resistance must not be smaller than the one
indicated in the Technical Data of the specific brake chopper.
6. Accessories
The brake chopper can also be assembled on module resistors by
means of an assembly kit. This kit can be ordered under the order
no. ER00370969.