Bypass Control Board Inputs And Outputs - ABB ACH550 User Manual

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has been enabled in the drive, the drive will attempt to automatically restart before
the motor is transferred to line power. The Automatic Transfer option is selected by
setting a configuration switch on the bypass control board. See "Check E-Bypass
Jumpers, Switches and Pots" on page 19. The Automatic Transfer LED is illuminated
green once the system has automatically transferred to bypass operation.
Output Contactor Control
In the unlikely event of failure in the bypass control electronics, the user can engage
the drive output contactor without the control electronics by using a configuration
jumper on the bypass control board. See "Output Contactor Control" on page 22.

Bypass Control Board Inputs and Outputs

The E-Bypass control board has five relay contact (digital) inputs, six relay outputs
and one digital output that are available for connection to external control circuits.
The internal 24VDC supply is normally used in conjunction with the relay contact
inputs. Use of an external 110 VAC power supply requires re-configuring Jumper J3.
Care should be taken when using external supply voltages so as not to damage the
drive and bypass electronics. The input and output functions are described below.
Refer to "Installation" for additional information and connection instructions.
Relay Contact Inputs
Start/Stop
The Start/Stop input is connected to a normally open contact that starts and stops
the system. When the E-Bypass is in the Drive mode and the ACH550 is in the Auto
mode, the Start/Stop input contact controls the motor by starting and stopping the
ACH550 drive. When the E-Bypass is in the Bypass mode and the Auto LED is
illuminated green, the Start/Stop input contact controls the motor by controlling the
bypass contactor.
Run Enable
The Run Enable input is connected to the series combination of any external
normally closed permissive contacts, such as damper end switches, that must be
closed to allow the motor to run. If any of these external contacts are open while a
Start command is present, the Enable LED will flash and the motor is prevented from
running.
Safety Interlock
The Safety Interlock input is connected to the series combination of any external
normally closed interlock contacts, such as Firestat, Freezestat, and high static
pressure switches – switches that must be closed to allow the motor to run. If any of
these external contacts are open, the Enable LED is not illuminated, the drive output
contactor, bypass contactor, and System Started relay are de-energized preventing
the motor from running.
Fireman's Override (Override 1)
The Fireman's Override (Override 1) input can be connected to an external contact
that is closed to select the Fireman's Override mode. See "Fireman's Override
Mode" on page 26 for a description of this mode.
Start-up
E-Bypass Configurations for ACH550 Drives