Application - ABB 615 series Technical Manual

Hide thumbs Also See for 615 series:

Table of Contents

1MAC059074-MB A

615 series ANSI

Technical Manual

occurs within the trip time up counting, the reset timer is activated. If the drop-off time

exceeds Reset delay time, the operation timer is reset.

The BLOCK input can be controlled with a binary input, a horizontal communication input

or an internal signal of the relay program. The activation of the BLOCK input prevents the

BLK2H output from being activated.

It is recommended to use the second harmonic and the waveform based

inrush blocking from the 87T function, if available.

Application

Transformer protections require high stability to avoid tripping during magnetizing inrush

conditions. A typical example of an inrush detector application is doubling the pickup

value of an overcurrent protection during inrush detection.

The inrush detection function can be used to selectively block overcurrent and ground-

fault function stages when the ratio of second harmonic component over the fundamental

component exceeds the set value.

Other applications of this function include the detection of inrush in lines connected to a

transformer.

Protection related functions

Table of Contents