Specifications

Mechanical Indicators
56
Wattmeter Scale Selection Reference Table
Although the maximum scale of a wattmeter can be determined by VT ratio ✕ CT ratio ✕ indicator rating (Po), the following table
shows the manufacturable scale values (minimum, standard and maximum) for various VT ratios and CT ratios.
If a scale value other than the standard value is desired, please specify a suitable scale within the manufacturable range.
Table of manufacturable maximum scales for wattmeters
Phase-wire system 1-phase 2-wire 3-phase 3-wire/3-phase 4-wire
CT ratio
Voltage
VT ratio
25/5
50/5
75/5
100/5
150/5
200/5
300/5
400/5
600/5
800/5
1200/5
1500/5
2000/5
3000/5
Minimum
Standard
Maximum
Minimum
Standard
Maximum
Minimum
Standard
Maximum
Minimum
Standard
Maximum
Minimum
Standard
Maximum
Minimum
Standard
Maximum
Minimum
Standard
Maximum
Minimum
Standard
Maximum
Minimum
Standard
Maximum
Minimum
Standard
Maximum
Minimum
Standard
Maximum
Minimum
Standard
Maximum
Minimum
Standard
Maximum
Minimum
Standard
Maximum
110
—
2
2.5
3
4
5
6
6
7.5
9
8
10
12
12
15
18
16
20
25
24
30
35
30
40
50
45
60
75
60
80
100
90
120
150
120
150
180
160
200
240
240
300
350
220
220/110
4
5
6
8
10
12
12
15
18
15
20
24
24
30
35
30
40
50
45
60
75
60
80
100
90
120
150
120
160
180
180
240
300
240
300
350
300
400
500
450
600
750
440
440/110
8
10
12
15
20
25
24
30
35
30
40
50
45
60
75
60
80
100
90
120
150
120
160
180
180
240
300
250
320
350
380
480
600
450
600
750
600
800
1000
900
1200
1500
110
—
4
5
6
8
10
12
12
15
18
15
20
25
24
30
35
30
40
50
45
60
75
60
80
100
90
120
150
120
160
180
180
240
300
240
300
350
300
400
500
450
600
750
220
220/110
8
10
12
15
20
25
24
30
35
30
40
50
45
60
75
60
80
100
90
120
150
120
160
180
180
240
300
250
320
350
380
480
600
450
600
750
600
800
1000
900
1200
1500
440
440/110
15
20
25
30
40
50
45
60
75
60
80
100
90
120
150
120
160
180
180
240
300
250
320
350
380
480
600
500
640
750
750
960
1200
900
1200
1500
1200
1600
1800
1800
2400
3000
3300
3300
/110
120
150
180
240
300
350
350
450
500
450
600
750
700
900
1000
900
1200
1500
1400
1800
2000
1800
2400
3000
2800
3600
4000
3800
4800
6000
6000
7200
8500
7000
9000
10
9000
12
15
14
18
20
6600
6600
/110
240
300
350
450
600
750
700
900
1000
900
1200
1500
1400
1800
2000
1800
2400
3000
2800
3600
4000
3800
4800
6000
6000
7200
8500
7500
9600
12
12
14
18
14
18
20
18
24
30
28
36
40
11000
11000
/110
400
500
600
800
1000
1200
1200
1500
1800
1500
2000
2500
2400
3000
3500
3000
4000
5000
4500
6000
7500
6000
8000
10
9000
12
15
12
16
18
18
24
30
24
30
35
30
40
50
45
60
75
22000
22000
/110
800
1000
1200
1500
2000
2500
2400
3000
3500
3000
4000
5000
4500
6000
7500
6000
8000
10
9000
12
15
12
16
18
18
24
30
25
32
35
38
48
60
45
60
70
60
80
100
90
120
150
33000
33000
/110
1200
1500
1800
2400
3000
3500
3500
4500
5000
4500
6000
7500
7000
9000
10
9000
12
15
14
18
20
18
24
30
28
36
40
38
48
60
60
72
85
70
90
100
90
120
150
140
180
200
66000
66000
/110
2400
3000
3500
4500
6000
7500
7000
9000
10
9000
12
15
14
18
20
18
24
30
28
36
40
38
48
60
60
72
85
75
96
120
120
140
180
140
180
200
180
240
300
280
360
400
1-phase 3-wire
100/200
—
4
5
6
8
10
12
12
15
18
15
20
24
24
30
35
30
40
50
45
60
75
60
80
100
90
120
150
120
160
180
180
240
300
240
300
350
300
400
500
450
600
750
: Scale units kW : Scale units MW
Manufacturable
range
Note 1. Some of the maximum scale values in the table deviate from the VT ratio ✕ CT ratio ✕ adjustment range multiplying factor. This is because the best values are
selected, and the values in the table are given priority.