ABB RELION 620 Series Technical Manual page 595

1MRS757644 F
4.3.6
4.3.6.1
4.3.6.2
4.3.6.3
4.3.6.4
620 series
Technical Manual
High-impedance/flux-balance based differential protection
for motors MHZPDIF
Identification
Function description
High-impedance/flux-balance based
differential protection for motors
Function block
GUID-3FADFABC-DDB3-471F-B542-94A885482F49 V1 EN
Figure 302: Function block
Functionality
The high-impedance/flux-balance based differential protection for motors function
MHZPDIF provides winding short circuit protection for motors.
MHZPDIF starts and operates when any of the three-phase differential currents,
ID_A, ID_B or ID_C, exceeds the set limit. The operation timer characteristic is
according to the definite time (DT).
This function contains a blocking functionality. It is possible to block the function
outputs, timers or the function itself, if desired.
Operation principle
The function can be enabled and disabled with the Operation setting. The
corresponding parameter values are "On" and "Off".
The operation of MHZPDIF can be described using a module diagram. All the
modules in the diagram are explained in the next sections.
GUID-215EFDB6-AA85-47EA-B633-350F706A60B4 V1 EN
Figure 303: Functional module diagram
Protection functions
IEC 61850 IEC 60617
identification identification
MHZPDIF 3dIHi>M
Section 4
ANSI/IEEE C37.2
device number
87MH
589