Cooling Fans; Control Electronics; Cabinet Layout - ABB ACS880-107 Hardware Manual

Operation principle and hardware description 29

Cooling fans

The cooling fan unit at the base of the inverter module contains two DC fans. The fans
are PWM-controlled according to an internal temperature measurement. The fan
carriage can be easily removed for fan replacement, or to allow access to the output
cable connections at the back of the cubicle.
The inverter module also has a small fan ventilating the circuit board compartment
inside the module. The fan can be serviced without removing the inverter module from
the cabinet.

Control electronics

Inverter units that have one or more R8i modules use a BCU control unit. The control
unit has inputs, outputs, and slots for option modules. A fiber optic link connects the
control unit to each inverter module. Safety circuits that use the built-in Safe torque
off (STO) functionality are connected to the control unit.
The control electronics are typically located in a 300 mm wide control cubicle (DCU),
which can also contain components of the auxiliary voltage circuit and optional features
such as relays and circuit breakers. The cubicle can also contain the control equipment
of another inverter unit. A 400 mm wide cubicle is optionally available.

Cabinet layout

1...3 inverter modules can be installed in one cubicle. The width of the cubicle is 400,
600 or 800 mm respectively. Each module has dedicated DC fuses. A DC
switch-disconnector is optional. An inverter unit with a switch-disconnector also has
a precharge circuit including a charging switch on the door. When connecting the
inverter unit to the DC bus, the charging switch is closed first. After the precharging
completes, the DC switch-disconnector can be closed and the charging switch opened.