ABB VFD Drive ACS 800

ACS 800 trips many times due to voltage dip in the system.

Case study:

AC drives (invertors) of ID and FD fans in New CPP trip as and when there was any voltage drop due to any fault in drown stream. Recent example is - Flash over in 33 KV line of Mehgao Mines on 14^th Oct -10

We have activated Scalar flystart option of AC drives (ACS 800) of ID & FD fans of all three boilers to overcome this type of tripping.

In this mode, drives behave like a generator when ever any voltage dip occurs, for a pre defined period (1 sec in our case). Electronic circuit of the drive gets sufficient voltage, generated from motor, in case of any drop in line voltage. If line voltage does not get normalized within 1 sec, drive generates trip command.

Note: All these setting have been changed in consultation with ABB service engineer.

By : Satendra Kumar Tiwari, ACC Limited

Before implementing these settings at your equipment, expert advice is must

Here are the specs...it may need to be adjusted...

http://www.joliettech.com/abb_acs-800_ac_drive_specifications.htm

One of the possibilities is that the supply cable(s) is/are undersized.

Refer to the relevant national electrical code, such as British Standard 7671, and assess.