Protecting The Resistor Cable Against Short Circuit; Mechanical Installation; Electrical Installation; Checking The Insulation Of The Brake Resistor Assembly - ABB ACS880-104 Hardware Manual

332 Resistor braking using frames R1i...R4i inverter modules
This is essential for safety since the inverter module may not be able to break the current
if the chopper remains conductive in a fault situation. An example wiring diagram is shown
below. ABB resistors are equipped with a thermal switch (1) inside the resistor assembly
as standard. The switch indicates overtemperature and overload.
We recommend that you also wire the thermal switch to a digital input of the inverter module.
L1 L2 L3
1 3 5
2 4 6
L1 L2 L3
2
1.
2.
3.
￭

Protecting the resistor cable against short circuit

The DC fuses of the inverter module will also protect the resistor cable if the cable is identical
with the inverter input cable.

Mechanical installation

All brake resistors must be installed outside the drive. Follow the resistor manufacturer's
instructions.

Electrical installation

￭

Checking the insulation of the brake resistor assembly

Check the insulation of each brake resistor assembly as follows:
1. Check that the resistor cable is connected to the resistor, and disconnected from the
inverter module terminals R+ and R-.
2. At the inverter end, connect the R+ and R- conductors of the resistor cable together.
Measure the insulation resistance between the combined conductors and the Protective
Earth (PE) conductor by using a measuring voltage of 1000 V DC. The insulation
resistance must be higher than 1 Mohm.
1
OFF
2
13
ON
14
Θ
1
K1
Thermal switch
Drive system
ACS880-104
3
4
3
10 +24V
x DIx