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

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.
ohm

Connection procedure


1. Connect the resistor cable to the R+ and R- terminals in the same way as the other
power cables. Use the same cable type as with the DC input cable. If a shielded three-
conductor cable is used, cut the third conductor, insulate it, and ground the twisted
shield of the cable (protective earth conductor of the resistor assembly) at both ends.
2. Connect the thermal switch of the brake resistor as described above under
the system against thermal
Resistor braking using frame R1i...R4i inverter modules 329
R+
R-
PE
overload.
Protecting