ABB ACH580-01 Series, Hardware Manual

Page: 341 / 396

Resistor braking 341
Placing the brake resistor
Install the resistors outside the drive in a place where they will cool.
Arrange the cooling of the resistor in a way that:
• no danger of overheating is caused to the resistor or nearby materials
• the temperature of the room the resistor is located in does not exceed the allowed
maximum.
Supply the resistor with cooling air/water according to the resistor manufacturer’s
instructions.
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. If the exhaust vents are connected to a ventilation
system, ensure that the material withstands high temperatures. Protect the resistor
against physical contact.
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. We recommend that you use resistors equipped with a thermal switch (1)
inside the resistor assembly. The switch indicates overtemperature and overload.