176
Calculation Formula
2. Voltage waveform peak (Upk), Voltage crest factor (Ucf), Current waveform peak (Ipk), Current
crest factor (Icf)
Wiring
Item
Single phase
2-wire
1P2W
Single phase
3-wire
1P3W
3-phase 3-wire
3P3W2M
3-phase 3-wire
3P3W3M
3-phase 4-wire
3P4W
Upk+
Upk−
[V]=
Up
c
Up
1
Up
4
Up
1
Up
2
Up
4
Up
1
Up
2
Up
3
Up
4
Up
12
Up
23
Up
31
Up
1
Up
2
Up
3
Up
4
During 1P3W1U
Without
Up
2
• For 3P3W2M wiring, it is assumed that
U
1S
−U
2S
+U
3S
= 0
• For 3P3W3M wiring, phase voltage
U
is measured from the virtual neutral point, and line voltage is
determined by calculation.
Ucf[ ]
Ucf
1
Ucf
4
Ucf
c
=
c
c
U
Up
Ucf
1
Ucf
2
Ucf
4
Ucf
1
Ucf
2
Ucf
3
Ucf
4
Ucf
12
Ucf
23
Ucf
31
Ucf
1
Ucf
2
Ucf
3
Ucf
4
During 1P3W1U
Without
Ucf
2
• The larger absolute value among +, − is used for
Up
C.
Ipk+
Ipk−
[A]=
Ip
c
Ip
1
Ip
4
Ip
1
Ip
2
Ip
4
Ip
1
Ip
2
Ip
3
Ip
4
• With 3P3W2M wiring, it is assumed that
I
1S
+I
2S
+I
3S
=0
.
Icf[ ]
Icf
1
Icf
4
Icf
c
=
c
c
I
Ip
Icf
1
Icf
2
Icf
4
Icf
1
Icf
2
Icf
3
Icf
4
• The larger absolute value among +, − is used for
Ip
C
.
c
: Measurement channel