ABB ACH550-UH User Manual page 385

ACH550 E-Clipse Bypass User's Manual 2-39
Advanced Override Mode (Override 2)
In the Advanced Override (Override 2) mode, the motor is powered either by the
drive through the drive output contactor or by AC line power through the bypass
contactor, depending upon the setting of parameter 1708. The user can switch to the
Advanced Override mode by closing the Advanced Override input contact (DI5 - if
programmed) or through serial comms. When Advanced Override is active, the
system does not respond to the Drive and Bypass keys. The Motor Run LED flashes
green when the system is in override. While in Advanced Override, the system
responds to bypass overloads and programmed faults. To satisfy the local AHJ
(Authority Having Jurisdiction), the system can be custom-programmed to
acknowledge or disregard certain faults, safeties and enables. The unit is default-
programmed to ignore all external safeties and run enables. See Group 17 for
programmability of the digital input and fault functions. Normally when the Advanced
Override is deactivated, the system returns to the previous operating mode and can
be controlled using the Drive and Bypass keys. If the system was previously in Hand
mode, the system reverts to Off mode. The exception to this is when the Smoke
Control (Override 1) input contact is closed, in which case the system remains in
Smoke Control mode.
Bypass functions overview