Protection Of Frame Sizes R7 And R8 (Acs800-U2, Acs800-U4, Acs800-Pc, Acs800-U7/07) - ABB ACS800 Hardware Manual

Protection of Frame Sizes R7 and R8 (ACS800-U2, ACS800-U4,
ACS800-PC, ACS800-U7/07)
A main contactor is not required for protecting against resistor overheating when the
resistor is dimensioned according to the instructions and the internal brake chopper
is in use. The drive will disable power flow through the input bridge if the chopper
remains conductive in a fault situation.
Note: If an external brake chopper (outside the drive module) is used, a main
contactor is always required.
A thermal switch (standard in ABB resistors) is required for safety reasons. The
cable must be shielded and not longer than the resistor cable.
97
Resistor Braking