Protecting The System In Brake Circuit Fault Situations - ABB ACS580 Series Hardware Manual

404 Resistor braking

Protecting the system in brake circuit fault situations

Protecting the system in cable and brake resistor short-circuit situations
The drive input fuses will also protect the resistor cable when it is identical with
the input power cable.
Protecting the system against thermal overload
The drive has a brake thermal model which protects the brake resistor against
overload. ABB recommends to enable the thermal model at start up.
ABB recommends to equip the drive with a main contactor for safety reasons even
when you have enabled the resistor thermal model. 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.
ABB recommends that you also wire the thermal switch to a digital input of the
drive, and configure the input to cause a fault trip at resistor overtemperature
indication.
L1 L2
1
1 3
2 4
L1 L2
2
1 Drive input power connection with a main contactor
2 Drive
3 Main contactor control circuit
4 Brake resistor thermal switch
5 Digital input. Monitors the brake resistor thermal switch.
3
L3
OFF
5
6
Θ
4
L3
1
2
13 3
ON
14 4
K1
5
x +24V
x DIx