KYORITSU 6315 Instruction Manual - Manual (Page 141)

Items to be calculated KEW6315
- 139 - KEW6315
Current unbalance ratio Aunb [%]
Displayed digit 5-digit
Display range 0.00% to100.00%
Wiring 3P3W, 3P4W
Equation ( )
( )
100
6 3 1
6 3 1
×








− +
− −
=
β
β
Iumb
( )
2
2
31
2
23
2
12
4
31
4
23
4
12
A A A
A A A
+ +
+ +
= β
* The 1st order components of harmonic current are used.
* For 3P4W system, phase voltages are converted to line voltages for
calculation.
A
12
= A
1
- A
2,
A
23
= A
2
- A
3,
A
31
= A
3
- A
1
Capacitance calculation
Displayed digit 4-digit, Unit: nF, µF, mF, kvar
Display range 0.000nF - 9999F, 0.000kvar - 9999kvar
Equation
[ ]
var 1
1
1
1
2
arg _
2
k
PF PF
P C
et T C C
C C








− − − × =
[ ]
F
PF PF V f
P
et T C C C
C µ








− − − Ч
Ч
Ч
=
1
1
1
1
2
10
2
arg _
2 2
9
π
C
c
: Capacitance needs for improvement
P
c
: Load power (active power)〔kW〕
f : Frequency
V
c
: R.m.s. voltage
PF
c
: Measured PF
PF
c_Target
: New power factor (target)
c : Measurement channel
1P2W-1 to 4
C
1
, C
2
, C
3
, C
4
, C
sum
=C
1
+C
2
+C
3
+C
4
1P3W(3P3W)-1
to 2
C
1
, C
2
, C
sum1
=C
1
+C
2
C
1
, C
2
, C
sum2
=C
3
+C
4
C
sum
=C
sum1
+ C
sum2
3P3W3A(3P4W)
C
1
, C
2
, C
3
, C
sum
=C
1
+C
2
+C
3