Transfer Trip: Overreaching, Underreaching Or Direct (2-Frequency); Phase Comparison Unblocking: Dual Or Segregated (2-Frequency); Fsk Mode Typical Wiring/Connections - Ametek UPLC-II System Manual

UPlC-ii™ System manual
3.7.4 Transfer Trip: Overreaching,
Underreaching or Direct (2-
Frequency)
The higher frequency (f H ), or "Guard" frequency,
is transmitted continually during normal condi-
tions. For a fault sensed by the overreaching (or
underreaching) pilot relay, the transmitter is shift-
ed to the low frequency (f L ), called "Trip" fre-
quency.
When using the UPLC-II™ or any permissive
overreaching or underreaching line relay system,
you can apply any bandwidth setting. However,
the best all around setting to use will be the wide
band, wide shift (600 Hz BW, ±250 Hz Shift)
equipment. If frequency spacing between other
Power-Line Carrier units is not an issue and relay
speed is critical, you may apply the extra wide
band (1200 Hz, ±500 Hz Shift) equipment.
Security against noise causing a false trip is also
increased some with the extra-wide band, but
increasing RX pre-trip delay has the largest
improvement on security. In any of these systems,
the usual power level combination will be 1 W for
guard and 10 W for the trip signal.
3.7.5 Phase Comparison Unblocking:
Dual or Segregated (2-
Frequency)
Phase Comparison relays use square wave signals
for operation. The transmitter is keyed to a "Trip
Positive" frequency when the relay square wave
goes positive, and is keyed to a
"Trip-Negative" frequency when
the relay square wave is at zero. The
Trip Positive frequency is frequen-
cy-shifted below f C ; the "Trip
Negative" frequency is frequency-
shifted above f C . Either frequency
can function as a trip or block,
depending on the local square wave.
Page 3–30
For Phase Comparison systems, you can use only
the wide band with wide shift or extra wide band
UPLC-II™. In the interest of conserving spec-
trum, the wide band, wide shift channel is most
common. However, if speed is important, you may
apply the extra wide band set. The most often
applied power level will be 10 watts for both
"Trip-Positive" and "Trip-Negative".
3.7.6 Three-Terminal Line Applications
When a three terminal line protection requires
Power-Line Carrier equipment, each terminal
must have one transmitter and 2 receivers, since
each terminal must receive a signal from each of
the 2 other ends of the line. Fig. 3–23 is a repre-
sentation of the transmitter/receiver complement
required to implement a single function: Hybrids
or other isolation devices are required between
transmitters and transmitters to receivers. See the
hybrid section, at the end of the chapter, for
details.
3.8 FSK Mode Typical
Wiring/Connections
Common wiring/connection diagrams for FSK
applications can be found on the following pages.
A
F1 C
TX
TX
F2
RX
RX
F3
RX
RX
Figure 3–23. FSK Three Terminal Line Application
F3
B
TX
F2
F2
RX
F1
F1
RX
F3