Hioki PW3360-20, Instruction Manual

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12.5 Calculation Formulas
181
Chapter 12 S
p
ecif
icat
ions
12
* Subscript c: measurement channel; M: number of sample points; s: sample point
number
* Subscript c: measurement channel; M: number 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
S 0
=
M 1
–

1
M
---
I
cs
 
2
S 0
=
M 1
–

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
  
s 0
=
M 1
–

1
M
---
U
cs
I
cs
  
s 0
=
M 1
–
