ABB ACS380 Series, Hardware Manual

Page: 135 / 186

Resistor braking 135
Protecting the system in brake circuit fault situations

Protecting the system in cable and brake resistor short-circuit
situations
The input fuses will also protect the resistor cable when it is identical with the input
cable.

Protecting the system against thermal overload
Equipping the drive with a main contactor is highly recommended for safety reasons.
Wire the contactor so that it opens in case the resistor overheats. This is essential for
safety since the drive will not otherwise be able to interrupt the main supply if the
chopper remains conductive in a fault situation. An example wiring diagram is shown
below. ABB recommends that you use resistors equipped with a thermal switch (1)
inside the resistor assembly. The switch indicates overtemperature and overload.
ABB recommends that you also wire the thermal switch to a digital input of the drive.
Mechanical installation
Refer to the resistor manufacturer’s instructions.
Drive
L1 L2 L3
1
2
3
4
5
6
13
14
3
4
1
2
K1

OFF
ON
L1 L2 L3
1 Drive
10 +24V
x DIx