Rectangular and ring current transformer cores for power systems Current transformer cores for precision
measuring instruments
Applications:
Current transformers for precise current measurement in power systems and precision measuring instruments (such as kilowatt-hour meters).
General Properties:
Higher permeability for higher measuring accuracy (when compared with ferrite)
Lower ampere turns and smaller dimension (when compared with ferrite transformers)
Less expensive (when compared with permalloy transformers)
Lower saturation induction for better ability against instrument breakdown (when compared with permalloy)
Lower core weight and manufacturing costs (when compared with permalloy)
Wider linear range than permalloy
Long durability between -55 and + 130 oC
Typical Properties of nanocrystalline, permalloy, and silicon-steel cores
|
Property\Core
|
Nanocrystalline
|
Permalloy
|
Silicon Steel
|
|
Saturation induction BS (Tesla)
|
1.25
|
0.75
|
2.03
|
|
Initial permeability µ0 (103)
|
40 - 80
|
50 - 80
|
1
|
|
Maximum permeability µm (103)
|
600
|
600
|
40
|
|
Curie temperature TC (oC)
|
570
|
400
|
740
|
|
Density (g/cm3)
|
7.20
|
8.75
|
7.65
|
|
Stack coeffiicient
|
³ 0.72
|
0.9
|
0.95
|
|
Thickness (mm)
|
0.03
|
0.15
|
0.3
|
Table 1. Rectangular Cores for current transformers in power systems
|
Core Code
|
Core dimension
(IW´IL/OW´OL/T*, mm)
|
Case dimension
(IW´IL/OW´OL/T*, mm)
|
Core mass
(kg/unit)
|
Turns ratio
N1:N2
|
Primary current
(mA)
|
Secondary voltage (mV)
|
|
CCTA-01
|
55´97/77´119/25
|
50´92/82´114/30
|
0.58
|
1:1
|
25
|
0.45
|
|
95
|
2.2
|
|
1500
|
53
|
|
CCTA-02
|
70´.90/100´200/30
|
65´85/105´125/36
|
0.81
|
1:1
|
200
|
15
|
|
1:1
|
500
|
50
|
|
CCTA-03
|
75´95/105´125/25
|
70´90/110´130/30
|
0.7
|
1:1
|
70
|
2
|
|
1:1
|
175
|
8
|
|
CCTA-04
|
80´95/120´135/25
|
75´90/125´140/30
|
1.09
|
1:1
|
80
|
1.7
|
|
1:1
|
600
|
41
|
|
CCTA-05
|
90´90/160´160/30
|
85´85/165´165/36
|
2.4
|
1:1
|
100
|
6
|
|
1:1
|
500
|
100
|
|
1:1
|
1000
|
140
|
|
CCTA-06
|
135´136/260´260/10
|
130´130/265´265/16
|
2.3
|
1:1
|
100
|
1.5
|
|
1:1
|
500
|
32
|
|
CCTA-07
|
82´602/138´658/45
|
75´595/145´665/55
|
8.8
|
1:1
|
100
|
1.2
|
|
1:1
|
1000
|
45
|
*IW = Inside Width, IL = Inside Length, OW = Outside Width, OL = Outside Length, T = Thickness
Cores with other customized dimensions are available upon request.
Table 2. Ring Cores for current transformers in power systems
|
Core Code
|
Core dimension
ID/OD×T* (mm)
|
Case dimension
ID/OD×T* (mm)
|
Core weight (kg/unit)
|
Turns ratio N1:N2 = 1:1
Input current (mA), frequency = 50 Hz
Output voltage (mV)
|
|
CCTB-01
|
1105/1165×15
|
1095/1175×25
|
8.35
|
Primary current
|
450
|
1200
|
2000
|
|
Secondary voltage
|
0.59
|
2.36
|
5.28
|
|
CCTB-02
|
415/520×15
|
409/526×23
|
6.08
|
Primary current
|
50
|
250
|
700
|
|
Secondary voltage
|
0.4
|
3
|
11
|
|
CCTB-03
|
305/490×15
|
299/496×23
|
9.1
|
Primary current
|
350
|
900
|
¡¡
|
|
Secondary voltage
|
5
|
20
|
¡¡
|
|
CCTB-04
|
315/395×35
|
309/401×43
|
8.2
|
Primary current
|
120
|
400
|
¡¡
|
|
Secondary voltage
|
3
|
11
|
¡¡
|
|
CCTB-05
|
198/248×30
|
192/254×37
|
2.76
|
Primary current
|
100
|
200
|
500
|
|
Secondary voltage
|
2
|
6
|
35
|
|
CCTB-06
|
198/248×20
|
192/254×27
|
1.84
|
Primary current
|
100
|
200
|
500
|
|
Secondary voltage
|
1.5
|
3.5
|
25
|
|
CCTB-07
|
155/200×30
|
150/205×36
|
2
|
Primary current
|
100
|
190
|
1000
|
|
Secondary voltage
|
10
|
38
|
255
|
|
CCTB-08
|
140/180×30
|
135/185×36
|
1.58
|
Primary current
|
40
|
80
|
240
|
|
Secondary voltage
|
1
|
2.9
|
15
|
|
CCTB-09
|
130/190×30
|
125/195×36
|
2.38
|
Primary current
|
40
|
80
|
240
|
|
Secondary voltage
|
1.2
|
3.8
|
17
|
|
CCTB-10
|
100/140×30
|
95/145×36
|
1.19
|
Primary current
|
30
|
120
|
500
|
|
Secondary voltage
|
0.85
|
6.8
|
68
|
|
CCTB-11
|
90/130×30
|
85/135×36
|
1.09
|
Primary current
|
30
|
120
|
500
|
|
Secondary voltage
|
0.7
|
6
|
55
|
|
CCTB-12
|
90/125×25
|
85/130×31
|
0.78
|
Primary current
|
30
|
120
|
500
|
|
Secondary voltage
|
0.9
|
7
|
70
|
|
CCTB-13
|
80/120×30
|
75/125×36
|
0.99
|
Primary current
|
200
|
500
|
¡¡
|
|
Secondary voltage
|
20
|
65
|
¡¡
|
|
CCTB-14
|
85/115×30
|
80/120×36
|
0.74
|
Primary current
|
30
|
120
|
500
|
|
Secondary voltage
|
0.7
|
6.5
|
55
|
|
CCTB-15
|
85/125×20
|
80/130×26
|
0.7
|
Primary current
|
30
|
120
|
500
|
|
Secondary voltage
|
0.62
|
5.5
|
50
|
*ID = Inside Diameter, OD = Outside Diameter, T = Thickness
Options for case materials: cast aluminium, stretched aluminium, welded aluminium, stainless steel, resin, plastics, etc.
Net thickness of case dimension: 5-8 mm.
Cores with other customized dimensions are available upon request (max. OD up to 1,300 mm).
Table 3. Cores for current transformers in precision measuring instruments
|
Core Code
|
Core dimension (mm)*
|
Input current
(50 Hz, mA)
|
Output
voltage (mV)
|
Core Code
|
Core dimension (mm)*
|
Input current
(50 Hz, mA)
|
Output
voltage (mV)
|
|
ID
|
OD
|
T
|
ID
|
OD
|
T
|
|
CCTC-01
|
9.3
|
13
|
10
|
50
|
> 2.0
|
CCTC-11
|
16
|
21
|
10
|
10
|
> 0.25
|
|
> 1.8
|
10
|
> 0.22
|
|
> 1.6
|
CCTC-12
|
17
|
24
|
10
|
10
|
> 0.2
|
|
CCTC-02
|
9.6
|
13.2
|
10
|
50
|
> 3
|
10
|
> 0.15
|
|
> 2.5
|
CCTC-13
|
18
|
24
|
10
|
30
|
> 0.9
|
|
10
|
> 0.25
|
CCTC-14
|
18
|
27
|
10
|
50
|
> 4
|
|
CCTC-03
|
9.6
|
15.3
|
10
|
50
|
> 4.0
|
> 3
|
|
> 3.0
|
> 2
|
|
CCTC-04
|
11
|
17
|
8
|
30
|
> 2
|
CCTC-15
|
19
|
25
|
10
|
30
|
> 0.9
|
|
> 1.5
|
50
|
> 3.5
|
|
> 1
|
> 3
|
|
CCTC-05
|
12.5
|
20
|
10
|
50
|
> 5.0
|
> 2.5
|
|
> 4.0
|
CCTC-16
|
20
|
25
|
10
|
10
|
> 0.18
|
|
> 3.0
|
> 0.15
|
|
CCTC-06
|
13.2
|
19
|
10
|
50
|
> 4.5
|
CCTC-17
|
20
|
30
|
10
|
10
|
> 0.2
|
|
> 4
|
50
|
> 4.5
|
|
CCTC-07
|
13.2
|
21.5
|
10
|
10
|
> 0.3
|
CCTC-18
|
20
|
30
|
15
|
50
|
> 9
|
|
20
|
> 0.55
|
> 8
|
|
50
|
> 6
|
CCTC-19
|
20
|
30
|
20
|
50
|
> 10
|
|
> 5
|
> 8
|
|
> 4.5
|
> 6
|
|
CCTC-08
|
14
|
19
|
10
|
10
|
> 0.2
|
CCTC-20
|
36
|
44
|
10
|
100
|
> 3
|
|
> 0.25
|
> 2.5
|
|
50
|
> 4
|
> 2
|
|
> 3
|
CCTC-21
|
40
|
50
|
10
|
20
|
> 0.3
|
|
> 2
|
100
|
> 4.5
|
|
CCTC-09
|
14
|
19
|
6.5
|
10
|
> 0.18
|
> 3.5
|
|
> 0.2
|
> 2.5
|
|
20
|
> 0.4
|
500
|
> 8
|
|
50
|
> 3.5
|
CCTC-22
|
50
|
60
|
10
|
100
|
> 3.0
|
|
> 3
|
> 2.0
|
|
> 2.5
|
> 1.5
|
|
CCTC-10
|
15
|
21
|
10
|
10
|
> 0.25
|
CCTC-23
|
61
|
69
|
10
|
100
|
> 0.9
|
|
50
|
> 4
|
|
> 3
|
*ID = Inside Diameter, OD = Outside Diameter, T = Thickness.
Cores with other customized dimensions are available upon request.
