S4 Elements
745
Transformer Management Relay
Se
tpoints
http://www.GEindustrial.com/multilin
5–73
GE Multilin
•
MINIMUM OPERATING VOLTAGE
: Enter the minimum value of voltage (in
terms of nominal VT secondary voltage) required to allow the Volts-per-Hertz 1
element to operate.
•
VOLTS-PER-HERTZ 1 PICKUP
: Enter the volts-per-hertz value (in V/Hz)
above which the Volts-per-Hertz 1 element will pickup and start the delay timer.
•
VOLTS-PER-HERTZ 1 SHAPE
: Select the curve shape to be used for the Volts-
per-Hertz 1 element. The inverse volts-per-hertz curve shapes are shown
below.
•
VOLTS-PER-HERTZ 1 DELAY
: Enter the time that the volts-per-hertz value
must remain above the pickup level before the element operates.
•
VOLTS-PER-HERTZ 1 RESET
: Enter the time that the volts-per-hertz value
must remain below the pickup level before the element resets.
The curve for the Inverse Curve 1 shape is derived from the formula:
(EQ 5.12)
where
T
= operate time (seconds)
D
= delay setpoint (seconds)
V
= fundamental RMS value of voltage (V)
F
= frequency of voltage signal (Hz)
Pickup
= volts-per-hertz pickup setpoint (V/Hz)
FIGURE 5–33: Volts Per Hertz Curve 1
The curve for the inverse curve 2 shape is derived from the formula:
(EQ 5.13)
where
T
= operate time (seconds)
D
= delay setpoint (seconds)
V
= fundamental RMS value of voltage (V)
F
= frequency of voltage signal (Hz)
Pickup = volts-per-hertz pickup setpoint (V/Hz)
T
D
V F
⁄
Pickup
-------------------
2
1
–
--------------------------------------
=
when
V
F
----
Pickup
>
0.01
0.1
1
10
100
1000
1.00
1.20
1.40
1.60
1.80
2.00
Multiples of Volts/Hertz Pickup
Time
Delay
Setting
ò
10
3
1
0.3
0.1
T
ime
to
T
rip
(seconds)
T
D
V F
⁄
Pickup
-------------------
1
–
-----------------------------
=
when
V
F
----
Pickup
>
Summary of Contents for Multilin 745
Page 2: ......
