Resistor Installation And Wiring; Protection Of Frame Sizes R7 And R8 - ABB ACS800-04 Hardware Manual

136 Resistor braking

Resistor installation and wiring

All resistors must be installed outside of the drive module in a place where they will
cool.
WARNING! The materials near the brake resistor must be non-flammable.
The surface temperature of the resistor is high. Air flowing from the
resistor is of hundreds of degrees Celsius. Protect the resistor against
contact.
Use the cable type used for drive input cabling (see
ensure the input fuses also protect the resistor cable. Alternatively, two-conductor
shielded cable with the same cross-sectional area can be used. The maximum length
of the resistor cable(s) is 10 m (33 ft). For the connections, see the power connection
diagram of the drive.

Protection of frame sizes R7 and R8

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 disables 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.
With Standard Control Program, wire the thermal switch as shown below. By default,
the drive coasts to a stop when the switch opens.
Thermal switch
(standard in ABB
resistors)
For other control programs, the thermal switch can be wired to a different digital
input. Programming of the input to trip the drive by "EXTERNAL FAULT" may be
needed. See the appropriate firmware manual.
RMIO:X22 or X2: X22
1 DI1
2 DI2
3 DI3
4 DI4
5 DI5
6 DI6
7 +24VD
8 +24VD
9 DGND1

10 DGND2
11 DIIL
Technical data
on page 99) to