ABB ACH550-UH User Manual page 383

ACH550 E-Clipse Bypass User's Manual
Bypass functions overview
Operating modes
Note: For normal operation with the bypass, place the drive control panel in the Auto
mode.
Drive Mode
Under normal conditions the system is in the Drive mode. The drive provides power
to the motor and controls its speed. The source of the drive's start/stop and speed
commands is determined by the Auto or Hand mode selection of the drive's control
panel. Commands come from the bypass control terminals (or serial communication)
when the Auto mode has been selected or directly from the drive control panel when
the Hand mode has been selected. The user can normally switch to the Drive mode
by pressing the Drive key on the bypass control panel.
Reverse Drive Mode
Reverse Drive mode is a subset of Drive mode; as such the drive provides power to
the motor and controls its speed and direction. The source of the drive's start/stop,
speed and direction commands is the Reverse Drive input (DI2 - if programmed).
In this mode the system acknowledges all of the same permissives (run and start
enables) as Drive mode. When the Reverse Drive input contact is closed with the
drive running, the drive reverses motor direction and continues running; with the
drive stopped, the drive starts and runs in the reverse direction. In either case the
motor operates at the constant speed programmed on the drive. No other start
command is required. See Parameter 1630 on page
programming and wiring requirements.
Bypass Mode
In the Bypass mode, the motor is powered by AC line power through the bypass
contactor. The source of the bypass start/stop commands is determined by the Auto
or Hand mode selection of the bypass' control panel. Commands come from the
bypass control terminals (or serial communication) when the Auto mode has been
selected or directly from the bypass control panel when the Hand mode has been
selected. The user can normally switch to the Bypass mode by pressing the Bypass
key on the bypass control panel. Alternative methods of bypass control called
Overrides are also available. Refer to the following descriptions of the Override
modes.
for a description of drive
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Bypass functions overview
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