ABB Remote I/O RIO600 Installation And Commissioning Manual page 126

Section 6
Commissioning
118
Operation principle
The Operation setting is used to enable or disable the function. The corresponding
parameter values are "On" and "Off".
The operation of MFAPSDE can be described using a module diagram. All modules
in the diagram are explained in the next sections.
Transient
detector
Io
frequency
admittance
Uo
calculation
General
criterion
GUID-0E9EC3FB-FBC8-4BFA-92E9-F7FFC42AE956 V1 EN
Figure 69: Functional module diagram
General fault criterion
The General fault criterion (GFC) module monitors the presence of earth fault in the
network and it is based on the value of the fundamental frequency zero-sequence
voltage defined as the vector sum of fundamental frequency phase voltage phasors
divided by three.
1 1 1
U U U
+ +
1
A B C
U
=
0
3
GUID-C4866966-64A3-4E7E-9794-8920040B61B5 V1 EN
When the magnitude of
detected. The GFC module reports the exceeded value to the Fault direction
determination module and Operation logic. The reporting is referenced as General
Fault Criterion release.
Set the correct system phase-to-phase voltage with the Nominal
Voltage setting under the SIM8F operating parameter. The function
uses this value internally for calculation.
The Voltage start value setting defines the basic sensitivity of the MFAPSDE
function. To avoid unselective start or operation, Voltage start value must always be
set to a value which exceeds the maximum healthy state zero-sequence voltage value,
Multi-
Fault
direction
determination
fault
1
exceeds the Voltage start value setting, an earth fault is
U
0
1MRS757488 H
MFAPSDE_InEF
MFAPSDE_St
MFAPSDE_Oper
Operation
logic
MFAPSDE_OpFw
MFAPSDE_OpRe
Timer
MFAPSDE_ReEF
(Equation 7)
Installation and Commissioning Manual
RIO600