Brochure

© 1998 Square D All Rights Reserved
26
5/98
Thermal Unit Selection
Tables 7 thru 12
Polyphase
Single
PH
Motor
Full-
Load
Current
(Amp)
Ther-
mal
Unit
No.
Maximum Fuse Rating
(Amp)
Single-
Motor
Instal-
lation
(N.E.C.
430-52)
Group Motor
Installation
(N.E.C. 430-53)
Class
K-9 or
Unclas-
sified
Fuse
Class
K-5
Fuse
0.29-0.32
0.33-0.36
0.37-0.39
0.40-0.47
0.53-0.59
B 0.44
B 0.51
B 0.57
B 0.63
B 0.71
0.6
0.6
0.8
0.8
1
15
15
15
15
15
30
30
30
30
30
0.57-0.63
0.64-0.69
0.70-0.77
0.78-0.86
0.87-0.96
B 0.81
B 0.92
B 1.03
B 1.16
B 1.30
1.25
1.4
1.4
1.6
1.8
15
15
15
20
20
30
30
30
30
30
0.97-1.11
1.12-1.23
1.24-1.37
1.38-1.55
1.56-1.75
B 1.45
B 1.67
B 1.88
B 2.10
B 2.40
2
2.5
2.5
2.8
3.5
20
20
20
25
25
30
30
30
30
30
1.76-1.92
1.93-2.16
2.17-2.50
2.51-2.81
2.82-3.16
B 2.65
B 3.00
B 3.30
B 3.70
B 4.15
3.5
4
4.5
5.6
6.25
25
25
30
30
30
30
30
30
30
30
3.17-3.40
3.41-3.76
3.77-4.00
4.01-4.68
4.69-5.18
B 4.85
B 5.50
B 6.25
B 6.90
B 7.70
7
7
8
9
10
30
30
30
30
30
30
30
30
30
30
5.19-5.51
5.52-6.19
6.20-7.12
7.13-8.15
8.16-8.60
10.2-11.2
B 8.20
B 9.10
B 10.2
B 11.5
B 12.8
B14
10
12
12
15
17.5
17.5
30
30
30
30
30
30
30
30
30
30
30
30
9.22-10.1
10.2-11.2
B 15.5
B 17.5
20
20
600 V
Max.
Group Fusing
Restrictions
Maximum
thermal unit
size: B 14
Maximum
branch-circuit
available
current: 5,000
Amp
symmetrical
11.3-12.0 B 19.5
20
250 V
Max.
25
Table 8
Motor Full-Load Current (Amp) Thermal
Unit
Number
2.T.U.1 PH 2 T.U.2 PH 3 T.U.
0.37-0.39
0.40-0.42
0.43-0.46
0.47-0.50
0.51-0.54
0.37-0.39
0.40-0.42
0.43-0.46
0.47-0.50
0.51-0.54
0.30-0.31
0.32-0.34
0.35-0.37
0.38-0.41
0.42-0.45
AR .45
AR .49
AR .54
AR .59
AR .65
0.55-0.59
0.60-0.65
0.66-0.71
0.72-0.78
0.79-0.86
0.55-0.59
0.60-0.65
0.66-0.71
0.72-0.78
0.79-0.86
0.46-0.49
0.50-0.54
0.55-0.56
0.57-0.62
0.63-0.68
AR .71
AR .78
AR .86
AR .95
AR 1.05
0.87-0.94
0.95-1.04
1.05-1.14
1.15-1.25
1.26-1.42
0.87-0.94
0.95-1.04
1.05-1.14
1.15-1.25
1.26-1.42
0.69-0.75
0.76-0.82
0.83-0.91
0.92-1.00
1.01-1.18
AR 1.15
AR 1.26
AR 1.39
AR 1.53
AR 1.68
1.43-1.62
1.63-1.75
1.76-1.91
1.92-2.07
2.08-2.25
1.43-1.62
1.63-1.75
1.76-1.91
1.92-2.07
2.08-2.25
1.19-1.30
1.31-1.41
1.42-1.53
1.54-1.69
1.70-1.79
AR 1.85
AR 2.04
AR 2.24
AR 2.46
AR 2.71
2.26-2.47
2.48-2.73
2.74-2.99
3.00-3.31
3.32-3.71
2.26-2.47
2.48-2.73
2.74-2.99
3.00-3.31
3.32-3.71
1.80-2.02
2.03-2.19
2.20-2.43
2.44-2.81
2.82-3.12
AR 2.98
AR 3.28
AR 3.62
AR 3.98
AR 4.37
3.72-4.15
4.16-4.65
4.66-5.11
5.12-5.68
5.69-6.24
3.72-4.15
4.16-4.65
4.66-5.11
5.12-5.68
5.69-6.24
3.13-3.47
3.48-3.89
3.90-4.30
4.31-4.69
4.70-5.19
AR 4.80
AR 5.3
AR 5.8
AR 6.4
AR 7.0
6.25-7.15
7.16-7.84
7.85-8.56
8.57-9.40
9.41-10.2
6.25-7.15
7.16-7.84
7.85-8.56
8.57-9.40
9.41-10.2
5.20-5.93
5.94-6.45
6.46-7.08
7.09-7.71
7.72-8.39
AR 7.7
AR 8.5
AR 9.3
AR 10.2
AR 11.2
10.3-10.7
10.8-12.2
12.3-14.1
14.2-15.9
16.0-18.0
10.3-10.7
10.8-12.2
. . . .
. . . .
. . . .
8.40-8.64
8.65-9.74
9.75-11.0
11.1-12.0
. . . .
AR 12.4
AR 13.6
AR 15.4
AR 17.6
AR 20.5
Following Selections for Size 1 Only
. . . .
. . . .
. . . .
16.0-18.1
18.2-20.8
10.8-12.2
12.3-14.4
14.2-15.9
16.0-18.1
18.2-20.8
. . . .
. . . .
11.1-12.4
12.5-13.9
14.0-15.9
AR 13.6
AR 15.4
AR 17.6
AR 20.5
AR 23
20.9-23.6
23.7-26.0
. . . .
. . . .
20.9-23.6
23.7-26.0
. . . .
. . . .
16.0-17.7
17.8-20.3
20.4-22.8
22.9-26.0
AR 27
AR 30
AR 35
AR 40
Table 10
Motor
Full-Load
Current (Amp)
Thermal
Unit
Number
43.6-47.3
47.4-51.3
51.4-54.6
54.7-59.7
59.8-65.1
CC 54.5
CC 59.4
CC 64.3
CC 68.5
CC 74.6
65.2-70.1
70.2-75.1
75.2-82.2
82.3-89.2
89.3-96.5
CC 81.5
CC 87.7
CC 94.0
CC 103
CC 112
96.6-104.
105.-113.
114.-123.
124.-132.
133.-150.
CC 121
CC 132
CC 143
CC 156
CC 167
Table 11
Motor
Full-Load
Current (Amp)
Thermal
Unit
Number
2 T.U. 3 T.U.
33.0-36.1
36.2-40.2
40.3-44.5
45.6-51.3
51.4-58.5
30.5-33.4
33.5-37.1
37.2-42.0
42.1-47.0
47.1-53.5
AU 44
AU 50
AU 56
AU 64
AU 72
58.6-62.6
62.7-71.3
71.4-77.1
77.2-86.9
87.0-93.3
53.6-57.5
57.6-64.4
64.5-69.4
69.5-77.4
77.5-83.6
AU 81
AU 88
AU 99
AU 110
AU 123
93.4-102.
103.-107.
108.-112.
113.-121.
122.-123.
83.7-92.9
93.0-100.
101.-104.
105.-115.
116.-119.
AU 135
AU 152
AU 169
AU 183
AU 198
124.-133.
. . . .
120.-123.
124.-133.
AU 217
AU 235
Table 12
Motor
Full-Load
Current (Amp)
Thermal
Unit
Number
92.-100.
101.-109.
110.-119.
120.-131.
132.-139.
DD 122
DD 121
DD 128
DD 140
DD 150
140.-156.
157.-166.
167.-180.
181.-189.
190.-209.
DD 160
DD 185
DD 213
DD 220
DD 230
210.-225.
226.-238.
239.-263.
264.-300.
DD 250
DD 265
DD 280
DD 300
Table 9
Motor
Full-Load
Current (Amp)
Thermal
Unit
Number
15.3-16.7
16.8-19.8
19.9-22.8
22.9-25.8
25.9-30.4
C20
C22
C26
C30
C34
30.5-31.9
32.0-34.2
34.3-38.8
38.9-44.2
44.3-50.2
C40
C42
C45
C51
C58
50.3-57.1
57.2-63.2
63.3-68.6
68.7-78.6
78.7-86.9
87.0-100.0
C66
C75
C83
C90
C 103
C 114
Table 7
Single Phase
Single
PH
Motor
Full-
Load
Current
(Amp)
Ther-
mal
Unit
No.
Maximum Fuse Rating
(Amp)
Single-
Motor
Instal-
lation
(N.E.C.
430-52)
Group Motor
Installation
(N.E.C. 430-53)
Class
K-9 or
Unclas-
sified
Fuse
Class
K-5
Fuse
0.33-0.36
0.37-.040
0.41-0.45
0.46-0.52
0.53-0.59
B 0.44
B 0.51
B 0.57
B 0.63
B 0.71
0.6
0.8
0.8
1
1.125
15
15
15
15
15
30
30
30
30
30
0.60-0.66
0.67-0.73
0.74-0.81
0.82-0.91
0.92-1.02
B 0.81
B 0.92
B 1.03
B 1.16
B 1.30
1.25
1.4
1.6
1.8
2.0
15
15
15
20
20
30
30
30
30
30
1.03-1.14
1.15-1.29
1.30-1.42
1.43-1.64
1.65-1.80
B 1.45
B 1.67
B 1.88
B 2.10
B 2.40
2.25
2.5
2.8
3.2
3.5
20
20
20
25
25
30
30
30
30
30
1.81-2.10
2.11-2.30
2.31-2.61
2.62-2.99
3.00-3.37
B 2.65
B 3.00
B 3.30
B 3.70
B 4.15
4.0
4.5
5.0
5.6
6.25
25
25
30
30
30
30
30
30
30
30
3.38-3.94
3.95-4.24
4.25-4.54
4.55-5.29
5.30-5.73
B 4.85
B 5.50
B 6.25
B 6.90
B 7.70
7
8
9
10
10
30
30
30
30
30
30
30
30
30
30
5.74-6.35
6.36-7.08
7.09-7.83
7.84-8.47
8.48-9.83
B 8.20
B 9.10
B 10.2
B 11.5
B 12.8
12
12
12
17.5
17.5
30
30
30
30
30
30
30
30
30
30
9.84-10.5
10.6-11.4
11.5-12.8
12.9-13.9
14.0-16.1
16.2-18.0
B14
B 15.5
B 17.5
B 19.5
B 22.
B 25.
20
20
25
25
25
25
Group Fusing
Restrictions
Maximum
thermal unit
size: B 12.8
Maximum
branch-circuit
available
current: 5,000
Amp
symmetrical