Schweitzer Engineering Laboratories SEL-251 - SEL Direction and Polarity Check Form

SEL DIRECTION AND POLARITY CHECK FORM
STATION:
DATE: TESTED BY:
SWITCH NO.: EQUIPMENT:
ROUTINE: OTHER:
INSTALLATION:
LOAD CONDITIONS
STATION READINGS: MW (OUT)(IN) MVAR (OUT)(IN) VOLTS AMPS
SEL READINGS:
MW (+)(-)
MVAR (+)(-)
AS SEEN ON
SCREEN
COMPANY NOTATION
1st LINE CHOSEN
(Y COMPONENT)
2nd LINE CHOSEN
(X COMPONENT)
CALCULATED
USE THE VALUES IN ROWS 1 AND 2 ABOVE TO DRAW PHASOR DIAGRAMS BELOW
Ia Ib Ic Va Vb Vc
I( ) I( ) I( ) V( ) V( ) V( )
MAGNITUDE
X
2
Y
2
+
ANGLE IN DEGREES
ARCTAN Y/X
R
O
W
1
R
O
W
2
TO
VALUE OF Va DEGREES
OBTAIN Va DEGREES = 0
USED TO DRAW
PHASOR DIAGRAM
@ Va DEGREES = 0, ANGLE
+120•
-120•
0•
VOLTAGES
0•
+120•
-120•
CURRENTS
DWG: A7-0446