Multilin SR469 - Phasors

5. ACTUAL VALUES A2 METERING DATA
5-13
5.3.9 PHASORS
y
3+$6256
y
>(17(5@#IRU#PRUH
Õ
ÕÕ
Õ
ENTER
ENTERENTER
ENTER
ESCAPE
ESCAPEESCAPE
ESCAPE
Ö
ÖÖ
Ö 9D#3+$625=
313(#DW######3ƒ#/DJ
Û
ÛÛ
Û
ESCAPE
ESCAPEESCAPE
ESCAPE
MESSAGE
MESSAGEMESSAGE
MESSAGE
Ú
ÚÚ
Ú
9E#3+$625=
313(#DW######3ƒ#/DJ
Û
ÛÛ
Û
ESCAPE
ESCAPEESCAPE
ESCAPE
MESSAGE
MESSAGEMESSAGE
MESSAGE
Ú
ÚÚ
Ú
9F#3+$625=
313(#DW######3ƒ#/DJ
Û
ÛÛ
Û
ESCAPE
ESCAPEESCAPE
ESCAPE
MESSAGE
MESSAGEMESSAGE
MESSAGE
Ú
ÚÚ
Ú
,D#3+$625=
313(#DW######3ƒ#/DJ
Û
ÛÛ
Û
ESCAPE
ESCAPEESCAPE
ESCAPE
MESSAGE
MESSAGEMESSAGE
MESSAGE
Ú
ÚÚ
Ú
,E#3+$625=
313(#DW######3ƒ#/DJ
Û
ÛÛ
Û
ESCAPE
ESCAPEESCAPE
ESCAPE
MESSAGE
MESSAGEMESSAGE
MESSAGE
×
××
×
,F#3+$625=
313(#DW######3ƒ#/DJ
DESCRIPTION:
To aid in wiring the following table can be used to determine if VTs and CTs are on the correct phases and that their polarity is correct.
Problems arising from incorrect wiring are extremely high unbalance levels (CTs) or erroneous power readings (CTs and VTs) or phase
reversal trips (VTs).
To correct wiring simply start the motor and record the phasors. Using the table below along with recorded phasors, system rotation, VT
connection type and motor power factor the correct phasors can be determined. Note that Va (Vab if delta) is always assumed to be
zero degrees and is the reference for all angle measurements.
Common problems include: Phase currents 180 degrees from proper location (CT polarity reversed)
Phase currents or voltages 120 or 240 degrees out (CT/VT on wrong phase)
3
∅
∅∅
∅
Wye VT Connection
ABC Rotation 72.5
°
°°
°
=0.3 pf lag 45
°
°°
°
=0.7 pf lag 0
°
°°
°
=1.00 pf -45
°
°°
°
=0.7 pf lead -72.5
°
°°
°
=0.2 pf lead
Va 0 0° lag 0° lag 0° lag 0
Vb 120 120 120 120 120
Vc 240 240 240 240 240
Ia 75 45 0 315 285
Ib 195 165 120 75 45
Ic 315 285 240 195 165
kW + + + + +
kVAR + + 0 - -
kVA + + + (=kW) + +
ACB Rotation 72.5
°
°°
°
=0.3 pf lag 45
°
°°
°
= 0.7 pf lag 0
°
°°
°
= 1.00 pf -45
°
°°
°
= 0.7 pf lead 72.5
°
°°
°
=0.2 pf lead
Va 0 0° lag 0° lag 0° lag 0
Vb 240 240 240 240 240
Vc 120 120 120 120 120
Ia 75 45 0 315 285
Ib 315 285 240 195 165
Ic 195 165 120 75 45
kW + + + + +
kVAR + + 0 - -
kVA + + + (=kW) + +