Function Block; Functionality; Operation Principle - ABB RELION 620 Series Technical Manual

Section 4
Protection functions
4.1.8.2
4.1.8.3
4.1.8.4
240

Function block

A070688-ANSI V1 EN
Figure 108: Function block

Functionality

The phase discontinuity protection 46PD is used for detecting unbalance situations caused
by broken conductors.
The function picks up and trips when the unbalance current I
prevent faulty operation at least one phase current needs to be above the minimum level.
46PD trips with DT characteristic.
The function contains a blocking functionality. It is possible to block the function output,
timer or the function itself, if desired.

Operation principle

The function can be enabled and disabled with the Operation setting. The corresponding
parameter values are "Enable" and "Disable".
The operation of phase discontinuity protection can be described by using a module
diagram. All the modules in the diagram are explained in the next sections.
GUID-1A3E3A3D-D45B-4A88-8D65-CBE389ED1518 V1 EN
Figure 109: Functional module diagram. I
phase sequence currents. I_A, I_B and I_C represent phase currents.
/I exceeds the set limit. To
2 1
and I represent positive and negative
1 2
1MAC504801-IB E
620 series ANSI
Technical Manual