Power Protection: Power Factor (55) - 7Sr12; Figure 3-33 Logic Diagram: Power Factor Protection (55) - Siemens 7SR12 Argus Manual

7SR11 & 7SR12 Description Of Operation
3.18 Power Protection: Power Factor (55) – 7SR12
Two power factor elements are provided.
Gn 55-n Setting sets the pick-up power factor of the element.
Under-power factor or over-power factor operation can be set by the Gn 55-n Operation setting.
Gn 55-n 1ph/3ph Power allows the settings to be based on any one phase power factor or the average power
factor of all three phases.
An output is given after elapse of the Gn 55-n Delay setting.
Operation of the power factor elements can be inhibited when:
The measured current is below the Gn 55 U/C Guard setting
A VT Fail condition is detected
Inhibit 55-n
I
L1
I
L2
I
L3
V
1
V
2
V
3
Chapter 1 Page 60 of 88
A binary or virtual input.
Gn 55-n Element
Enabled
Gn 55-n VTS
Action
Inhibit
&
VT Fail
Inhibit 55-n
Gn 55-n U/C
Guarded
Enabled
Gn 55-n U/C Guard
Setting
<
&
&
<
<

Figure 3-33 Logic Diagram: Power Factor Protection (55)

Gn55-n: Operation: Under/Over
Gn55-n: 1ph/3ph Power
Gn55-n: Dir. Control
Gn55-n: Setting
En.
&
-W +W
-VAr -VAr
-W +W
+VAr +VAr
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Gn 55-n Delay
55-n
General Pickup