ABB ACS850-04 series, Hardware Manual

Page: 158 / 164

Resistor braking
158
Maximum cable length
The maximum length of the resistor cable(s) is 10 m (33 ft).
EMC compliance of the complete installation
Note: ABB has not verified that the EMC requirements are fulfilled with external
user-defined brake resistors and cabling. The EMC compliance of the complete
installation must be considered by the customer.
Mechanical installation
See the resistor manufacturer’s instructions.
Electrical installation
Connection diagram
See the power cable connection diagram of the drive, page 84 .
Connection procedure
• Connect the resistor cables to the R+ and R- terminals in the same way as the
other power cables. If a shielded three-conductor cable is used, cut the third
conductor and ground the twisted shield of the cable (protective earth conductor
of the resistor assembly) at both ends.
• Connect the thermal switch of the brake resistor as described in section Thermal
overload protection on page 157 .
Brake circuit commissioning
• Enable the brake chopper function. Please note that a brake resistor must be
connected when the chopper is enabled.
• Switch off the overvoltage control of the drive.
• Adjust any other relevant parameters in group 48.
For more information, see the firmware manual.
WARNING! If the drive is equipped with a brake chopper but the chopper is not
enabled by the parameter setting, the internal thermal protection of the drive against
resistor overheating is not in use. In this case, the brake resistor must be
disconnected.
Note : Some brake resistors are coated with oil film for protection. At the start-up, the
coating burns off and produces a little bit of smoke. Ensure proper ventilation at the
start-up.