55 Power Factor - Siemens 7SR51 Device Manual

Functional Tests
9.9 Protection Functional Tests
Note that these elements may be set as directional. If this is the case, the phase angle of the current must be
set with respect to the voltage to produce operation of the elements.
Voltage Setting (V, p-p)
51-1 Pickup
51-2 Pickup
51-3 Pickup
51-4 Pickup
Element Blocking
The Voltage Controlled Overcurrent function can be set to Inhibit for VT Supervision operation.
This functionality should be checked. Apply balanced voltage and current. Reduce a-phase voltage to cause a
VTS condition. Increase 3P current until the element operates at its full setting, i.e. 51V settings are not used.
Element
51-1
51-2
51-3
51-4
Check correct indication, trip output, alarm contacts.

55 Power Factor

9.9.19
Apply balanced 3 phase rated voltage and current. Increase current phase angle until the LED assigned to '55-
n' is on. Record this angle in the table below. Decrease the angle until the LED resets. Record the angle.
55-1
55-2
If the element is set with 55-n UC Guard Enabled, the setting can be tested by applying the test current
at a level below the 55-n U/C Guard Setting at a power in the operate range. Increase the current until
the relay operates.
UCG
Power Factor
Element Blocking
The Power Factor elements can be blocked by Binary Input Inhibit. This functionality should be
checked.
Element
55-1
55-2
Check correct indication, trip output, alarm contacts, waveform record.
When testing is complete reinstate any of the disabled functions.
488
I Setting Multiplier
55 Setting Angle
UCG Setting (⋅ Power Element
I ) Used for Test
rated
BI Inhibits
Measured (V, p-p)
Calculated PU Measured
VTS Action
Pick-Up
Blocked Current Unblocked
(D.O.) Current (P.U.)
Reyrolle 7SR5, Overcurrent Protection Device, Device Manual
C53000-G7040-C014-1, Edition 11.2019
Tolerance
Drop-Off
Notes