Signals - ABB RELION REX640 Technical Manual

Section 5
Protection related functions
5.4.7
5.4.8
Table 1025: PHIZ Group settings (Basic)
Parameter
Security Level
1086
Most of the electrical network faults are earth faults. Conventional protection systems
based on overcurrent, impedance or other principles are suitable for detecting
relatively low-impedance faults which have a relatively large fault current.
However, a small percentage of the earth faults have a very large impedance. They are
comparable to load impedance and consequently have very little fault current. These
high-impedance faults do not pose imminent danger to power system equipment.
However, they are a considerable threat to people and property. The IEEE Power
System Relay Committee working group on High Impedance Fault Detection
Technology defines High Impedance Faults as those that 'do not produce enough fault
current to be detectable by conventional overcurrent relays or fuses.
PHIZ always needs sensitive Io measurement.
High-impedance fault (PHIZ) detection requires a different approach than that for
conventional low-impedance faults. Reliable detection of PHIZ provides safety to
humans and animals. ABB has developed innovative technology for high-impedance
fault detection with over ten years of research resulting in many successful field tests.

Signals

Table 1023: PHIZ Input signals
Name
I3P
IRES
BLOCK
CB_CLOSED
CB_OPEN
Table 1024: PHIZ Output signals
Name
OPERATE
Settings
Values (Range) Unit
1...10
Type Default Description
SIGNAL - Three-phase currents
SIGNAL - Residual current
BOOLEAN 0=False Block signal for activating the blocking mode
BOOLEAN 0=False Circuit Breaker Closed input
BOOLEAN 0=False Circuit Breaker Open input
Type Description
BOOLEAN Operate
Step Default
1 5
1MRS759142 C
Description
Security Level
Technical Manual
REX640