Hioki PW3360-20 - Calculation Formulas

12.5 Calculation Formulas
201
Chapter 12 Specifications
12
* Subscript c: measurement channel; M: number of sample points; s: sample point number
* Subscript c: measurement channel; M: numbe
r of sample points; s: sample point number
12.5 Calculation Formulas
Voltage and current RMS values
Wiring
setting
Item
Single-phase
2 wire
Single-phase
3 wire
Three-phase
3 wire
Three-
phase
4 wire
1P2W 1P3W 1P3W1U 3P3W2M 3P3W3M 3P4W
Voltage
U [Vrms]
U
1
U
1
U
2
U
1
U
1
U
2
U
12
(U
12s
=U
1s
-U
2s
)
U
1
(U
1s
=u
1s
-u
2s
)
U
2
(U
2s
=u
2s
-u
3s
)
U
3
(U
3s
=u
3s
-u
1s
)
U
1
U
2
U
3
U
c
=
• For 3P3W2M connections, it is assumed that U
1s
- U
2s
- U
12s
= 0.
• For 3P3W3M connections, the phase voltage u is measured from the virtual neutral point
and used to calculate the line-to-line voltage.
Current
I [Arms]
I
1
I
1
I
2
I
1
I
2
I
12
(I
12s
= -I
1s
-I
2s
)
I
1
I
2
I
3
I
1
I
2
I
3
I
c
=
• For 3P3W2M, it is assumed that I
1s
+ I
2s
+ I
12s
= 0.
1
M
---
U
cs

2
S0=
M1–

1
M
---
I
cs

2
S0=
M1–

Active power
Wiring
setting
Item
Single-phase
2 wire
Single-phase
3 wire
Three-phase
3 wire
Three-
phase
4 wire
1P2W 1P3W 1P3W1U 3P3W2M 3P3W3M 3P4W
Active power
P [W]
P
1
P
1
P
2
P
1
P
2
=
P
1
P
2
P
1
P
2
P
3
P
c
=
P=P
1
+P
2
P=P
1
+P
2
+P
3
• The active power P polarity symbols indicate the direction of current flow as either con-
sumption (+P) or regeneration (-P).
1
M
---
U
1s
– I
2s

s0=
M1–

1
M
---
U
cs
I
cs

s0=
M1–
