Placing The Brake Resistor - ABB ACS355 series User Manual

408 Appendix: Resistor braking
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Placing the brake resistor

Install all resistors 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.
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Protecting the system in brake circuit fault situations
Protecting the system in cable and brake resistor short-circuit situations
For short-circuit protection of the brake resistor connection, see
connection on page 388. Alternatively, a two-conductor shielded cable with the same
cross-sectional area can be used.
Protecting the system in brake resistor overheating situations
The following setup is essential for safety – it interrupts the main supply in fault
situations involving chopper shorts:
• Equip the drive with a main contactor.
• Wire the contactor so that it opens if the resistor thermal switch opens (an
overheated resistor opens the contactor).
Below is a simple wiring diagram example.
Fuses
ACS355
Electrical installation
For the brake resistor connections, see the power connection diagram of the drive on
page 51.
L1 L2 L3
1 3 5
K1
2 4 6
U1 V1 W1
Q Thermal switch of the resistor
Brake resistor