GE P444 User Manual

Setting
P44x/EN ST/Hb
6
MiCOM P40 Agile
P442, P444 (ST) 4-
17
Menu text Default setting
Setting range
Step size
Min Max
GROUP 1 – DISTANCE ELEMENTS
Vmem Validity 10s 0 10s 10mss
The duration of the voltage memory availability after fault detection can be set. When the
voltage memory is declared unavailable (e.g. the V Mem Validity set duration has expired,
SOTF Mode, no healthy network to record memory voltage), other polarizing quantities can
be considered. These include zero, negative and positive sequence (if voltage is sufficient).
Otherwise directional decision is forced to forward.
Earth I Detect 0.05*I1 0*I1 0.1*I1 0.01*I1
The residual current threshold (Earth I Detect.) is used by the conventional algorithm to
detect earth faults.
Fault Locator
KZm Mutual Comp 0 0 7 0.001
KZm Angle 0° 0° 360° 0.1°
Load Blinder En
R< Blinder Lim
15/In Ω 0.001/In Ω 500/In Ω 0.001/In Ω
Load/B Angle 45° 15° 65° 1°
Load Blinder V 15 V 1 V 70 V 0.5 V
• Remark: The settings dealing with the tilt (‘Z1m Tilt Angle’, ‘Z1p Tilt Angle’, ‘Z2p/Zp/Zq
Tilt Angle’) and the evolving forward zone detection to zone1 (to avoid a Z1 detection
in case of impedance locus getting out from the quad (due to remote CB operating)
but crossing the Z1 before being out from the quad (with enough points that a Z1
decision can be confirmed if that timer has been set to 0 ms).
2.2 Distance protection schemes (“Distance Scheme” menu)
The option of using separate channels for Directional Earth Fault (DEF) aided tripping, and
distance protection schemes, is offered in the P442 and P444 relays. Alternatively, the aided
DEF protection can share the distance protection signalling channel, and the same scheme
logic. In this case, a permissive overreach or blocking distance scheme must be used. The
aided tripping schemes can perform single pole tripping. The relays include basic five-zone
distance scheme logic for stand-alone operation (where no signalling channel is available)
and logic for a number of optional additional schemes. The features of the basic scheme are
available even if an additional scheme has been selected or not.
The function is based on a specification with a dedicated application equivalent to a
customised weak infeed.

GE P444 Specifications

General

Brand	GE
Model	P444
Category	Protection Device
Language	English