Bypass Contactors; Operator Control - ABB ACH 400 User Manual

Chapter 2 – Overview of ACH 400 with Electronic Bypass

Bypass Contactors

Motor Overload
Protection

Operator Control

Electronic Bypass
Options
2-4
The bypass circuit available with the ACH 400 Electronic Bypass includes
two contactors. One contactor is the bypass contactor (2M) that can be used to
manually connect the motor directly to the incoming power line in the event
that the ACH 400 is out of service. The other contactor is the ACH 400 output
contactor (1M for R1 through R4 and 3M for R5 through R9) that disconnects
the ACH 400 from the motor when the motor is operating in the Bypass
mode. The drive output contactor and the bypass contactor are interlocked to
prevent "back feeding," applying line voltage to the ACH 400 output
terminals.
In the Drive mode, motor overload protection is provided by the ACH 400.
In the Bypass mode, motor overload protection is provided by the bypass
control board.
WARNING: If power is applied and the switches and contacts in the control
circuit are commanding the motor to run, the motor will start as soon as the
overload protection is reset.
Use caution when resetting the overload protection to make sure it is safe to
start the motor.
The ACS-PAN-B Control Panel is a keypad with an LCD unit that provides
status indication and operator control for the ACH 400 drive. In normal
operation with the Electronic Bypass, the ACH 400 should be placed in the
Auto mode of operation by pressing the Auto key on the ACS-PAN-B Control
Panel. Refer to the ACH 400 User's Manual for additional information on the
ACS-PAN-B Control Panel and other aspects of ACH 400 operation.
The Electronic Bypass has a separate keypad that is used for selecting the
Drive or Bypass mode of operation and manually starting and stopping the
motor in the Bypass mode. The bypass keypad has LED indicating lights that
indicate the status of both the bypass and the drive. The bypass keypad is
described in detail in the Detailed Description of Operation.
In addition to the line reactor and circuit breaker options described above, the
Electronic Bypass has space for installing an ABB fieldbus adapter module.
ACH 400 with Electronic Bypass User's Manual