Hioki PQ3198 - Page 238

13.8 Calculation Formula
232
c: measured channel, M: number of samples per period, s: number of sampling points
-3. RMS Voltage (Urms), RMS Current (Irms)
Single Phase 2-wire
1P2W
Single Phase
3-wire
1P3W
3-Phase, 3-Wire,
2-Measurement
3P3W2M
3-Phase, 3-Wire,
3-Measurement
3P3W3M
3-Phase, 4-Wire
3P4W
Urms U
1
U
4
Uc=
U
1
U
2
U
4
Line-to-line voltage
U
12
=
U
32
=
U
31
is calculated from
the RMS value for
(U3s=U2s-U1s).
Line-to-line voltage
U
12
=
U
23
=
U
31
=
Phase voltage
U
1
U
2
U
3
U
4
U
4
U
4
Phase voltage
U
1
=
U
2
=
U
3
=
Line-to-line voltage
U
12
=
U
23
=
U
31
=
U
4
U
4
Uave=
Line-to-line voltage
Uave=
Line-to-line voltage
Uave=
Phase voltage
Uave=
Phase voltage
Uave=
Line-to-line voltage
Uave=
• Calculated with 10 waveforms (50 Hz measurement) or 12 waveforms (60 Hz measurement). For 400 Hz measurement,
t
he calculation is performed with 80 waveforms.
• For 3-phase 3-wire connections, the phase voltage is calculated so that the neutral point is at the center. The CH4 RMS
vo
ltage can be calculated regardless of the connection type.
Irms I
1
I
4
Ic=
I
1
I
2
I
4
I
1
I
2
I
3
is calculated from
the RMS value for
(I3s=-I1s-I2s).
I
4
I
1
I
2
I
3
I
4
I
1
I
2
I
3
I
4
Iave= Iave= Iave= Iave=
• Calculated with 10 waveforms (50 Hz measurement) or 12 waveforms (60 Hz measurement). For 400 Hz measurement,
t
he calculation is performed with 80 waveforms.
• The CH4 RMS current can be calculated regardless of the connection type.
Phase
System
Items
1
M
---
Ucs()
2
s0=
M1–

1
M
---
U1s()
2
s0=
M1–

1
M
---
U2s()
2
s0=
M1–

1
M
---
U1s()
2
s0=
M1–

1
M
---
U2s()
2
s0=
M1–

1
M
---
U3s()
2
s0=
M1–

Phase voltage
1
M
---
U1s U3s–
3
-------------------------


2
s0=
M1–

1
M
---
U2s U1s–
3
-------------------------


2
s0=
M1–

1
M
---
U3s U2s–
3
-------------------------


2
s0=
M1–

1
M
---
U1s U2s–()
2
s0=
M1–

1
M
---
U2s U3s–()
2
s0=
M1–

1
M
---
U3s U1s–()
2
s0=
M1–

1
2
---
U
1
U
2
+()
1
2
---
U
12
U
32
+()
1
3
---
U
12
U
23
U
31
++()
1
3
---
U
1
U
2
U
3
++()
Phase voltage
1
3
---
U
1
U
2
U
3
++()
1
3
---
U
12
U
23
U
31
++()
1
M
---
Ics()
2
s0=
M1–

1
2
---
I
1
I
2
+()
1
2
---
I
1
I
2
+()
1
3
---
I
1
I
2
I
3
++()
1
3
---
I
1
I
2
I
3
++()
HIOKI PQ3198A961-02