Type FB Buck-Boost Transformers
Application
The type FB Insulating and Buck-Boost Transformer has four separate windings, two windings in the primary and two windings in the secondary. The unit is designed for use as an isolating transformer or as auto-transformer. As an auto transformer, the unit can be connected to buck (decrease) or Boost (increase) a supply voltage. When connected in either the Buck or Boost mode, the unit is no longer an isolating transformer but is an autotransformer.
Autotransformers are more economical and physically smaller than equivalent two-winding transformers designed t carry the same load. They will perform the same function as two-winding transformers with the exception of insulating or isolating two circuits . Since autotransformers may transmit line disturbances directly , they may be prohibited in some areas by local building codes. Before applying them, care should be taken to assure that they are acceptable according to local code.
Note: Autotransformers are not used in close Delta connections as they introduce a phase shift into the circuit. As isolating transformers, these units can accommodate a high voltage of 120 x 240 volts (SB12N and SB16N series) or 240 x 480 volts (SB24N series). For the units with two 12 volt secondaries, the low voltage output can be 12 volts, 24 volts, or 3- wire 12/24 volts. Volts. For the units with two 16 volt secondaries, these output voltages can be 16 volts, 32 volts, or 3-wire 16/32 volts. For the units with two 24 volt secondaries, these output voltages can be 24 volts, 48 volts, or 3 wire 24/28 volts. The unit is capacity rated (KVA) as any conventional transformer.
Operation
Electrical and electronic equipment is designed to operate on a standard supply
voltage. When the supply voltage is constantly too high or too low, (usually
greater than (5%), the equipment fails to operate at maximum efficiency.
Buck-Boost transformer is a simple and economical, means of correcting this
off-standard voltage up to (20%. A Buck-Boost transformer will NOT, however,
stabilize a fluctuating voltage. Buck Boost transformers are suitable for use in
a three-phase autotransformer bank in either direction to supply 3-wire loads.
They are not suitable for use in a three-phase autotransformer bank to supply a
4-wire unbalanced load when the source is a 3-wire circuit.
Selection
To select the proper transformer for Buck-Boost applications, determine:
Six Step Selection
Choose the selection table with the correct number of phases. Tables I, III, and V for single-phase applications and Table II, IV, and VI for three-phase applications. Tables I and II are for 120x 240-12/24 volts: Tables III, IV are for 120 x 240-16/32 volts; and Tables V and VI are for 240 x 480-24/48 volts. (Refer to FPT catalog pages 13, 14, 15)
Line/Load voltage combinations are listed across the top of the selection table. Select a line/load voltage combination which comes closest to matching your application.
Follow the selected column down until you find either the load KVA or load amps of your application. If you do not find the exact value, go on to the next highest rating.
Follow across the table to the far left-hand side to find the rated KVA of the transformer you need.
Follow the column of your line/load voltage to the bottom to find the connection diagram for this application. Note: Connection diagrams show low voltage and high voltage connection terminals. Either can be input or output depending upon Buck or Boost application.
In the case of three-phase loads either two or three single-phase transformers are required as indicated in the “quantity required “ line at the bottom of Table II, IV or VI Select depending on whether a Wye connected bank of three transformers with a neutral is required or weather an open Delta connected bank of two transformers for a Delta connected load will be suitable.
For line/load voltages not listed on the table, use the pair listed on the table that is slightly above your application for reference. Then apply the first formula at the bottom of Table II, IV, or VI to determine “New” output voltage. The new KVA rating can be found using the second formula.
Buck Boost Technical Data
Type FB: 115°C Rise , 180°C Insulation System, Non-Ventilated, Indoor/Outdoor
Type |
KVA |
Catalog Number |
Taps |
Approximate Dimensions |
Aprx. Wt. in Lbs. |
Weather Shield |
Connection |
||
H |
W |
D |
|||||||
120X240-12/24 Volts, 60Hz, No Taps |
|||||||||
FB |
0.050 0.100 0.150 |
SB12N.050F SB12N.100F SB12N.150F |
No Taps No Taps No Taps |
8-1/4 8-1/4 9-1/4 |
3-1/4 3-1/4 4 |
4-1/4 4-1/4 5 |
8 10 14 |
N/R N/R N/R |
M M M |
0.250 0.500 0.750 1 |
SB12N.250F SB12N.500F SB12N.750F SB12N1F |
No Taps No Taps No Taps No Taps |
9-1/4 11-1/4 11-1/4 11-1/4 |
4 5-1/4 5-1/4 5-1/4 |
5 6-1/2 6-1/2 6-1/2 |
15 21 25 28 |
N/R N/R N/R N/R |
M M M M |
|
1.5 2 3 5 |
SB12N1.5F SB12N2F SB12N3F SB12N5F |
No Taps No Taps No Taps No Taps |
13-1/4 13-1/4 13-1/4 15 |
6-1/4 6-1/4 6-1/4 10-3/16 |
7-3/4 7-3/4 7-3/4 10-5/8 |
45 50 60 110 |
N/R N/R N/R N/R |
M M M M |
|
120X240-16/32 Volts, 60Hz, No Taps |
|||||||||
FB |
0.050 0.100 0.150 |
SB16N.050F SB16N.100F SB16N.150F |
No Taps No Taps No Taps |
8-1/4 8-1/4 9-1/4 |
3-1/4 3-1/4 4 |
4-1/4 4-1/4 5 |
8 10 14 |
N/R N/R N/R |
M M M |
0.250 0.500 0.750 1 |
SB16N.250F SB16N.500F SB16N.750F SB16N1F |
No Taps No Taps No Taps No Taps |
9-1/4 11-1/4 11-1/4 11-1/4 |
4 5-1/4 5-1/4 5-1/4 |
5 6-1/2 6-1/2 6-1/2 |
15 21 25 28 |
N/R N/R N/R N/R |
M M M M |
|
1.5 2 3 5 |
SB16N1.5F SB16N2F SB16N3F SB16N5F |
No Taps No Taps No Taps No Taps |
13-1/4 13-1/4 13-1/4 15 |
6-1/4 6-1/4 6-1/4 10-3/16 |
7-3/4 7-3/4 7-3/4 10-5/8 |
45 50 60 110 |
N/R N/R N/R N/R |
M M M M |
|
240X480-24/48 Volts, 60Hz, No Taps |
|||||||||
FB |
0.050 0.100 0.150 |
SB24N.050F SB24N.100F SB24N.150F |
No Taps No Taps No Taps |
8-1/4 8-1/4 9-1/4 |
3-1/4 3-1/4 4 |
4-1/4 4-1/4 5 |
8 10 14 |
N/R N/R N/R |
M M M |
0.250 0.500 0.750 1 |
SB24N.250F SB24N.500F SB24N.750F SB24N1F |
No Taps No Taps No Taps No Taps |
9-1/4 11-1/4 11-1/4 11-1/4 |
4 5-1/4 5-1/4 5-1/4 |
5 6-1/2 6-1/2 6-1/2 |
15 21 25 28 |
N/R N/R N/R N/R |
M M M M |
|
1.5 2 3 5 |
SB24N1.5F SB24N2F SB24N3F SB24N5F |
No Taps No Taps No Taps No Taps |
13-1/4 13-1/4 13-1/4 15 |
6-1/4 6-1/4 6-1/4 10-3/16 |
7-3/4 7-3/4 7-3/4 10-5/8 |
45 50 60 110 |
N/R N/R N/R N/R |
M M M M |
Buck Boost Selection Tables
Table I Single-Phase
Single-Phase |
Boosting |
Bucking |
|||||||||||||
Insulating Transformer Rating |
Line Voltage (Available) |
95 | 100 | 105 | 208 | 215 | 215 | 220 | 225 | 135 | 240 | 240 | 245 | 250 | 225 |
Load Voltage (Output) |
114 | 120 | 115 | 120 | 208 | 229 | 237 | 242 | 113 | 120 | 208 | 222 | 227 | 240 | |
0.05 KVA |
Load KVA AMPS |
.24
2.08 |
.25
2.08 |
.50
4.17 |
.50
4.17 |
.43
2.08 |
.48
2.08 |
.49
2.08 |
.50
2.08 |
.52
4.59 |
.55
4.59 |
.48
2.29 |
.51
2.29 |
.52
2.29 |
1.05
4.38 |
0.075 KVA |
Load KVA AMPS |
.36
3.13 |
.38
3.13 |
.72
6.25 |
.75
6.25 |
.65
3.13 |
.72
3.13 |
.74
3.13 |
.76
3.13 |
.78
6.88 |
.83
6.88 |
.72
3.44 |
.76
3.44 |
.78
3.44 |
1.58
6.56 |
0.1 KVA |
Load KVA AMPS |
.48
4.17 |
.50
4.17 |
.96
8.33 |
1.00
8.33 |
.87
4.17 |
.95
4.17 |
.99
4.17 |
1.01
4.17 |
1.04
9.16 |
1.10
9.16 |
.95
4.58 |
1.02
4.58 |
1.04
4.58 |
2.10
8.75 |
0.15 KVA |
Load KVA AMPS |
.72
6.25 |
.75
6.25 |
1.44
12.50 |
1.50
12.50 |
1.30
6.25 |
1.43
6.25 |
1.48
6.25 |
1.51
6.25 |
1.55
13.75 |
1.65
13.75 |
1.43
6.88 |
1.53
6.88 |
1.56
6.88 |
3.15
13.13 |
0.25 KVA |
Load KVA AMPS |
1.19
10.42 |
1.25
10.42 |
2.40
20.83 |
2.50
20.83 |
2.17
10.42 |
2.38
10.42 |
2.47
10.42 |
2.52
10.42 |
2.60
22.92 |
2.75
22.92 |
2.38
11.46 |
2.54
11.46 |
2.60
11.46 |
5.25
21.88 |
0.5 KVA |
Load KVA AMPS |
2.37
20.83 |
2.50
20.83 |
4.80
41.67 |
5.00
41.67 |
4.33
20.83 |
4.77
20.83 |
4.94
20.83 |
5.04
20.83 |
5.18
45.83 |
5.50
45.83 |
4.77
22.92 |
5.09
22.92 |
5.20
22.92 |
10.50
43.75 |
0.75 KVA |
Load KVA AMPS |
3.56
31.25 |
3.75
31.25 |
7.19
62.50 |
7.50
62.50 |
6.50
31.25 |
7.15
31.25 |
7.41
31.25 |
7.56
31.25 |
7.77
68.75 |
8.25
68.75 |
7.15
34.38 |
7.63
34.38 |
7.80
34.38 |
15.75
65.63 |
1 KVA |
Load KVA AMPS |
4.75
41.67 |
5.00
41.67 |
9.58
83.33 |
10.00
83.33 |
8.67
41.67 |
9.53
41.67 |
9.88
41.67 |
10.08
41.67 |
10.36
91.66 |
11.00
91.66 |
9.53
45.83 |
10.17
45.83 |
10.40
45.83 |
21.00
87.50 |
1.5 KVA |
Load KVA AMPS |
7.13
62.50 |
7.50
62.50 |
14.38
125.0. |
15.00
125.00 |
13.00
62.50 |
14.30
62.50 |
14.82
62.50 |
15.13
62.50 |
15.54
137.50 |
16.50
137.50 |
14.30
68.75 |
15.26
68.75 |
15.61
68.75 |
31.50
131.25 |
2 KVA |
Load KVA AMPS |
9.50
83.33 |
10.00
83.33 |
19.17
166.66 |
20.00
166.66 |
17.33
83.33 |
19.07
83.33 |
19.75
83.33 |
20.17
83.33 |
20.72
183.33 |
22.00
183.33 |
19.07
91.66 |
20.35
91.66 |
20.81
91.66 |
42.00
175.00 |
3 KVA |
Load KVA AMPS |
14.25
125.00 |
15.00
125.00 |
28.75
250.00 |
30.00
250.00 |
26.00
125.00 |
28.60
125.00 |
29.63
125.00 |
30.25
125.00 |
31.08
275.00 |
33.00
275.00 |
28.60
137.50 |
30.53
137.50 |
31.21
137.50 |
63.00
262.50 |
5 KVA |
Load KVA AMPS |
23.75
208.33 |
25.00
208.33 |
47.92
416.66 |
50.00
416.66 |
43.33
208.33 |
47.67
208.33 |
49.37
208.33 |
50.42
208.33 |
51.79
458.33 |
55.00
458.33 |
47.67
229.17 |
50.88
229.17 |
52.02
229.17 |
105.00
437.50 |
Connection Diagram | B | B | A | A | D | D | D | D | A | A | D | D | D | C |
Table ii Three-Phase
Three Phase |
Boosting |
Bucking |
|||||||||||||
Insulating Transformer Rating |
Line |
189Y 106 |
195Y 113 |
200Y 115 |
208Y 120 |
416Y 240 |
416Y 240 |
189 |
208 |
220 |
218 |
229 |
250 |
255 |
264 |
Load |
208 |
234 | 240 | 229 | 457 |
436 |
208 |
229 |
242 |
208 |
208 |
227 |
232 |
240 |
|
0.05 KVA |
KVA AMPS |
1.50
4.17 |
.84
2.08 |
.86
2.08 |
1.65
4.17 |
1.65
2.08 |
3.15
4.17 |
.75
2.08 |
.83
2.08 |
.87
2.08 |
1.58
4.39 |
.83
2.29 |
.90
2.29 |
.92
2.29 |
.95
2.29 |
0.075 KVA |
KVA AMPS |
2.25
6.25 |
1.27
3.13 |
1.30
3.13 |
2.48
3.13 |
4.72
6.25 |
1.13
3.13 |
1.24
3.13 |
1.31
3.13 |
2.36
6.56 |
1.24
3.44 |
1.35
3.44 |
1.35
3.44 |
1.38
3.44 |
1.43
3.44 |
0.1 KVA |
KVA AMPS |
3.00
8.33 |
1.67
4.17 |
1.73
4.17 |
3.30
8.33 |
3.30
4.17 |
6.20
8.33 |
1.50
4.17 |
1.65
4.17 |
1.75
4.17 |
3.15
8.75 |
1.65
4.58 |
1.80
4.58 |
1.84
4.58 |
1.90
4.58 |
0.15 KVA |
KVA AMPS |
4.50
12.50 |
2.54
6.25 |
2.60
6.25 |
4.96
12.50 |
4.96
6.25 |
9.44
12.50 |
2.26
6.25 |
2.48
6.25 |
2.62
6.25 |
4.73
13.13 |
2.48
6.88 |
2.71
6.88 |
2.76
6.88 |
2.86
6.98 |
0.25 KVA |
KVA AMPS |
7.50
20.83 |
4.22
10.42 |
4.33
10.42 |
8.30
20.83 |
8.25
19.42 |
15.75
20.83 |
3.75
10.42 |
4.13
10.42 |
4.37
10.42 |
7.88
21.88 |
4.13
11.46 |
4.50
11.46 |
4.61
11.46 |
4.76
11.46 |
0.5 |
KVA |
15.01
41.67 |
8.44
20.83 |
8.66
20.83 |
16.60
41.67 |
16.50
20.83 |
31.50
41.67 |
7.50
20.83 |
8.26
20.83 |
8.72
20.83 |
15.76
43.75 |
8.26
22.92 |
9.01
22.92 |
9.21
22.92 |
9.53
22.92 |
0.75 |
KVA |
22.52
62.50 |
12.67
31.25 |
12.99
31.25 |
24.90
62.50 |
24.75
31.25 |
47.25
62.50 |
11.26
31.25 |
12.39
31.25 |
13.10
31.25 |
23.64
65.63 |
12.39
34.38 |
13.52
34.38 |
13.82
34.38 |
14.29
34.38 |
1 |
KVA |
30.02
83.33 |
16.89
41.67 |
17.32
41.67 |
33.20
83.33 |
33.00
41.67 |
63.00
83.33 |
15.01
41.67 |
16.51
41.67 |
17.47
41.67 |
31.52
87.50 |
16.51
45.83 |
18.02
45.83 |
18.42
45.83 |
19.05
45.83 |
1.5 |
KVA |
45.03
125.00 |
25.33
62.50 |
25.98
62.50 |
49.80
125.00 |
49.50
62.50 |
94.50
125.00 |
22.52
62.50 |
24.77
62.50 |
26.20
62.50 |
47.28
131.25 |
24.77
68.75 |
27.03
68.75 |
27.63
68.75 |
28.53
68.75 |
2 |
KVA |
60.06
166.67 |
33.77
83.33 |
34.64
83.33 |
66.40
166.67 |
66.00
83.33 |
126.00
166.66 |
30.02
83.33 |
33.03
83.33 |
34.93
83.33 |
63.05
175.00 |
33.03
91.67 |
36.04
91.67 |
36.84
91.67 |
38.11
91.67 |
3 |
KVA |
90.07
250.00 |
50.66
125.00 |
51.96
125.00 |
99.59
250.00 |
99.00
125.00 |
180.00
250.00 |
445.03
125.00 |
49.54
125.00 |
52.39
125.00 |
94.57
262.50 |
49.54
137.50 |
54.06
137.50 |
55.25
137.50 |
57.16
137.50 |
5 |
KVA |
150.11
416.67 |
84.44
208.33 |
86.60
208.33 |
165.99
416.67 |
165.00
208.33 |
318.00
416.66 |
75.05
208.33 |
82.56
208.33 |
87.32
208.33 |
157.62
438.50 |
82.56
229.17 |
90.10
229.17 |
92.09
229.17 |
95.26
229.17 |
Number
|
3 | 3 | 3 | 3 | 3 | 3 | 2 | 2 | 2 | 2 | 2 | 2 | 2 | 2 | |
F | E | E | F | J | K | G | G | G | H | G | G | G | G |
Table III Single-Phase
Single-Phase |
Boosting |
Bucking |
|||||||||||||
Insulating Transformer Rating |
Line Voltage (Available) |
95 | 100 | 105 | 208 | 215 | 215 | 220 | 225 | 135 | 240 | 240 | 245 | 250 | 225 |
Load Voltage (Output) |
120 | 113 | 119 | 225 | 244 | 229 | 235 | 240 | 120 | 212 | 225 | 230 | 234 | 239 | |
0.05 KVA |
Load KVA AMPS |
0.19 1.56 |
0.35 3.13 |
0.37 3.13 |
0.37 1.56 |
0.38 1.56 |
0.72 3.12 |
0.73 3.13 |
0.75 3.122 |
0.42 3.54 |
0.38 1.77 |
0.75 3.30 |
0.77 3.33 |
0.78 3.33 |
0.08 3.33 |
0.075 KVA |
Load KVA AMPS |
0.28 2.34 |
0.53 4.69 |
0.56 4.69 |
0.55 2.34 |
0.57 2.34 |
1.07 4.69 |
1.10 4.89 |
1.12 4.69 |
0.63 5.31 |
0.56 2.66 |
1.12 5.00 |
1.15 5.00 |
1.17 5.00 |
120 500.6 |
0.1 KVA |
Load KVA AMPS |
0.38 3.13 |
0.71 6.25 |
0.74 6.25 |
0.74 3.13 |
0.75 3.13 |
1.43 6.25 |
1.47 6.25 |
1.50 6.25 |
0.84 7.08 |
0.75 3.54 |
1.50 6.67 |
1.53 6.67 |
1.56 6.6 |
120 6.67 |
0.15 KVA |
Load KVA AMPS |
0.56 4.69 |
1.06 9.38 |
1.12 9.36 |
1.11 4.69 |
1.14 4.69 |
2.15 9.37 |
2.20 9.37 |
2.25 9.37 |
1.27 10.63 |
1.13 5.31 |
2.25 10.00 |
2.30 10.00 |
2.34 10.00 |
2.39 10.00 |
0.25 KVA |
Load KVA AMPS |
0.9-4 7.81 |
1.77 15.63 |
1.8615 63 |
1.84 7.81 |
1.90 7.81 |
3.58 15.62 |
3.67 15.62 |
3.75 15.62 |
2.11 17.71 |
1.88 8.85 |
3.75 16.67 |
3.83 16.67 |
3.91 16.67 |
3.98 16.67 |
0.5 KVA |
Load KVA AMPS |
1.88 15.63 |
3.54 31.25 |
3.72 31.25 |
3.68 15.63 |
3.81 15.63 |
7.17 31.25 |
7.33 31.25 |
7.50 31.25 |
4.22 35.42 |
3.75 17.71 |
7.50 33.33 |
7.66 33.33 |
7.81 33.33 |
7.79 33.33 |
0.75 KVA |
Load KVA AMPS |
2.82 23.44 |
5.31 46.88 |
5.58 46.88 |
5.53 23.44 |
5.71 23.44 |
10.75 46.87 |
11.00 46.87 |
11.25 46.87 |
6.33 53.13 |
5.63 26.56 |
11.25 50.00 |
11.48 50.00 |
11.48 50.00 |
11.95 50.00 |
1 KVA |
Load KVA AMPS |
3.76 31.25 |
7.08 62.50 |
7.44 62.50 |
7.37 31.25 |
7.61 31.25 |
14.33 62.50 |
14.67 62.50 |
15.00 62.50 |
8.44 70.83 |
7.50 35.42 |
15.00 66.67 |
15.31 66.67 |
15.62 66.67 |
15.94 66.67 |
1.5 KVA |
Load KVA AMPS |
5.64 46.88 |
10.63 93.75 |
11.16 93.75 |
11.05 46.88 |
11.42 46.88 |
21.50 93.75 |
22.00 93.75 |
22.50 93.75 |
12.66 106.25 |
11.25 53.13 |
22.50 100.00 |
22.97 100.00 |
23.44 100.00 |
23.91 1000 |
2 KVA |
Load KVA AMPS |
5.64 46.88 |
10.63 93.75 |
11.16 93.75 |
11.05 46.88 |
11.42 46.88 |
21.50 93.75 |
22.00 93.75 |
22.50 93.75 |
12.66 106.25 |
11.25 53.13 |
22.50 100.00 |
22.97 100.00 |
23.44 100. |
31.87 133.33 |
3 KVA |
Load KVA AMPS |
11.28 93.75 |
21.25 167.50 |
22.31 187.50 |
22.10 93.75 |
22.84 93.75 |
43.00 187.51 |
44.00 187.50 |
45.00 187.50 |
25.31 212.50 |
22.50 106.25 |
45.00 200.00 |
45.94 200.00 |
46.87 200. |
47.81 200.00 |
5 KVA |
Load KVA AMPS |
18.80 156.25 |
35.42 312.5 |
37.19 312.50 |
36.83 156.25 |
38.07 156.25 |
71.67 312.50 |
73.33 312.50 |
75.00 312.50 |
42.19 354.17 |
37.50 177.08 |
75.00 333.33 |
76.56 333.33 |
78.12 333.33 |
79.893 33.33 |
Diagram | B | A | A | D | D | C | C | C | A | D | C | C | C | C |
Table IV Three-Phase
Three Phase |
Boosting |
Bucking |
||||||||||
Insulating Transformer Rating |
Line |
183Y 106 |
208Y 120 |
195 |
208 |
225 |
240 |
245 |
250 |
256 |
265 |
272 |
Load |
208Y/1 |
236Y/1 |
208 |
236 |
240 |
208 |
230 |
234 |
240 |
234 |
240 |
|
0.05 KVA |
KVA AMPS |
1.12 3.13 |
1.28 3.13 |
1.13 3.12 |
0.64 1.56 |
1.30 3.12 |
0.65 1.80 |
1.33 3.33 |
1.35 3.33 |
1.39 3.33 |
0.72 1.77 |
0.74 1.77 |
0.075 KVA |
KVA AMPS |
1.68 4.89 |
1.91 4.69 |
1.69 4.69 |
0.96 2.34 |
1.95 4.69 |
0.97 2.70 |
1.99 5.00 |
2.08 5.00 |
2.08 5.00 |
1.08 2.66 |
1.10 2.66 |
0.1 KVA |
KVA AMPS |
2.25 |
2.56 6.25 |
2.25 6.25 |
1.28 3.13 |
2.60 6.25 |
1.30 3.61 |
2.65 6.67 |
2.71 6.67 |
2.77 6.67 |
1.47 3.545 |
1.48 3.55 |
0.15 KVA |
KVA AMPS |
3.37 9.36 |
3.83 9.38 |
3.38 9.37 |
1.91 4.69 |
3.90 9.37 |
1.96 5.41 |
3.98 10.00 |
4.06 10.00 |
4.16 10.00 |
2.15 5.31 |
2.21 5.31 |
0.25 KVA |
KVA AMPS |
5.61 15.63 |
6.83 15.82 |
5.63 15.62 |
3.19 7.81 |
6.50 15.82 |
3.25 9.01 |
6.83 16367 |
6.77 16.67 |
6.93 16.67 |
3.39 16.367 |
3.68 8.85 |
0.5 |
KVA |
11.23 |
12.76 |
11.25 |
6.38 |
12.99 |
6.50 |
13.25 |
13.53 |
13.86 |
7.17 |
7.36 |
0.75 |
KVA |
16.84 |
19.14 |
16.89 |
9.58 |
19.49 |
9.74 |
19.89 |
20.30 |
20.78 |
10.75 |
11.04 |
1 |
KVA |
22.45 |
25.52 |
22.52 |
12.76 |
25.98 |
12.99 |
26.52 |
27.06 |
27.71 |
14.34 |
14.72 25.42 |
1.5 |
KVA |
33.68 |
38.28 |
33.77 |
19.14 |
38.97 |
19.49 |
39.78 |
40.59 |
41.57 |
21.52 |
22.08 |
2 |
KVA |
44.90 |
51.04 |
45.03 |
25.52 |
51.96 |
25.98 |
53.04 |
54.13 |
56.43 |
28.69 |
29.44 |
3 |
KVA |
67.36 |
76.56 |
67.56 |
38.28 |
77.94 |
38.97 |
79.57 |
81.19 |
83.14 |
83.14 |
44.17 |
5 |
KVA |
1.12 |
127.59 |
112.58 |
63.80 |
129.90 |
64.95 |
136.31 |
136.32 |
138.56 |
71.72 |
73.61 |
Number |
|
3 |
3 |
2 |
2 |
2 |
2 |
2 |
2 |
2 |
2 |
2 |
|
F |
F |
H |
G |
H |
L |
H |
H |
H |
G |
G |
Table V Single-Phase
Single-Phase |
Boosting |
Bucking |
||||||||||||
Insulating Transformer Rating |
Line Voltage (Available) |
230 |
280 |
416 |
425 |
430 |
435 |
440 |
450 |
460 |
277 |
480 |
480 |
504 |
Load Voltage (Output) |
277 |
420 |
457 |
467 |
473 |
457 |
484 |
472 |
483 |
230 |
436 |
456 |
480 |
|
0.05 |
Load
KVA |
.29 1.04 |
.44 1.04 |
.48 1.04 |
.49 1.04 |
.49 1.04 |
.95 2.08 |
.50 1.04 |
.98 2.08 |
1.01 2.08 |
.29 1.25 |
.50 1.15 |
1.05 2.29 |
1.10 2.29 |
0.075 |
Load
KVA |
.43 1.56 |
.65 1.56 |
.71 1.56 |
.73 1.56 |
.74 1.56 |
1.42 3.12 |
.75 1.56 |
1.47 3.12 |
1.51 3.12 |
.43 1.87 |
.75 1.72 |
1.57 1.72 |
1.57 3.43 |
1 |
Load
KVA |
.58 2.08 |
.87 2.08 |
.95 2.08 |
.97 2.08 |
.99 2.08 |
1.90 4.17 |
1.01 2.08 |
1.97 4.17 |
2.01 4.17 |
.58 2.50 |
1.00 2.29 |
2.09 4.58 |
2.20 4.58 |
0.15 |
Load
KVA |
.87 3.13 |
1.31 3.13 |
1.43 3.13 |
1.46 3.13 |
1.48 3.13 |
2.86 6.25 |
1.51 3.13 |
2.95 6.25 |
3.02 6.25 |
.86 3.75 |
1.50 3.44 |
3.14 6.88 |
3.30 6.88 |
0.25 |
Load
KVA |
1.44 5.21 |
2.19 5.21 |
2.38 5.21 |
2.43 5.21 |
2.46 5.21 |
4.76 5.21 |
2.52 5.21 |
4.92 10.42 |
5.03 10.42 |
1.44 6.25 |
2.50 5.73 |
5.23 11.46 |
5.50 11.46 |
0.5 |
Load
KVA |
2.89 10.42 |
4.38 10.42 |
4.76 10.42 |
4.86 10.42 |
4.93 10.42 |
9.52 20.83 |
5.04 10.42 |
9.83 20.83 |
10.06 20.83 |
2.88 12.50 |
5.00 11.46 |
10.45 22.92 |
11.00 22.92 |
0.75 |
Load
KVA |
4.33 15.63 |
6.56 15.63 |
7.14 15.63 |
7.30 15.63 |
7.39 15.63 |
14.28 31.25 |
7.56 15.63 |
14.75 31.25 |
15.09 31.25 |
4.31 18.75 |
7.40 17.19 |
15.68 34.38 |
16.50 34.38 |
1 |
Load
KVA |
5.77 20.83 |
8.57 20.83 |
9.52 20.83 |
9.73 20.83 |
9.85 20.83 |
19.04 41.67 |
10.08 20.83 |
19.67 41.67 |
20.13 41.67 |
5.75 25.00 |
9.99 22.92 |
20.90 45.83 |
22.00 45.83 |
1.5 |
Load
KVA |
8.66 31.25 |
13.13 31.25 |
14.28 31.25 |
14.59 31.25 |
14.78 31.25 |
28.56 62.50 |
15.13 31.25 |
29.50 62.50 |
30.19 62.50 |
8.63 37.50 |
14.99 34.38 |
31.35 68.75 |
33.00 68.75 |
2 |
Load
KVA |
11.54 41.67 |
17.50 41.67 |
19.04 41.67 |
19.46 41.67 |
19.71 41.67 |
38.08 83.33 |
20.17 41.67 |
39.33 83.33 |
40.25 83.33 |
11.50 50.00 |
19.98 45.83 |
41.80 91.67 |
44.00 91.67 |
3 |
Load
KVA |
17.31 62.50 |
26.25 62.50 |
28.56 62.50 |
29.19 62.50 |
29.56 62.50 |
57.13 125.00 |
30.25 62.50 |
59.00 125.00 |
60.38 125.00 |
17.25 75.00 |
29.98 68.80 |
62.70 137.50 |
66.00 137.50 |
5 |
Load
KVA |
28.90 104.20 |
43.80 104.20 |
47.60 104.20 |
48.60 104.20 |
49.30 104.20 |
95.20 208.30 |
50.40 104.20 |
98.30 208.30 |
100.60 208.30 |
28.80 125.00 |
50.00 114.60 |
104.50 229.20 |
110.00 229.20 |
Connection Diagram |
B |
D |
D |
D |
D |
C |
D |
C |
C |
B |
D |
C |
C |
Table VI Three-Phase
Three Phase |
Boosting |
Bucking | |||||||||||||||
Insulating Transformer Rating |
Line |
399Y
230 |
380 | 430 | 440 | 460 | 460 | 480 | 480 | 440 | 440 | 460 | 460 | 480 | 480 | 500 | 500 |
Load |
480Y
277 |
420 | 473 | 462 | 506 | 483 | 528 | 504 | 400 | 419 | 438 | 418 | 457 | 436 | 455 | 477 | |
0.05 KVA |
KVA AMPS |
.86
1.40 |
.76
1.04 |
.85
1.04 |
1.66
2.08 |
.91
1.04 |
1.74
2.08 |
.95
1.04 |
1.82
2.08 |
.79
1.14 |
1.58
2.18 |
1.66
2.18 |
.83
1.14 |
1.73
2.18 |
.86
1.14 |
.90
1.14 |
1.80
2.18 |
0.075 KVA |
KVA AMPS |
1.29
1.56 |
1.13
1.56 |
1.27
1.56 |
2.49
3.12 |
1.36
1.56 |
2.61
3.12 |
1.42
1.56 |
2.72
3.12 |
1.19
1.71 |
2.37
3.27 |
2.48
3.27 |
1.24
1.71 |
2.59
3.27 |
1.29
1.71 |
1.35
1.71 |
2.70
3.27 |
0.1 KVA |
KVA AMPS |
1.73
2.08 |
1.51
2.08 |
1.70
2.08 |
3.33
4.16 |
1.82
2.08 |
3.48
4.16 |
1.90
2.08 |
3.63
4.16 |
1.59
2.29 |
3.17
4.37 |
3.31
4.37 |
1.66
2.29 |
3.46
4.37 |
1.73
2.29 |
1.80
2.29 |
3.61
4.37 |
0.15 KVA |
KVA AMPS |
2.60
3.12 |
2.27
3.12 |
2.56
3.12 |
4.99
6.24 |
2.73
3.12 |
5.22
6.25 |
2.85
3.12 |
5.45
6.24 |
2.38
3.43 |
4.75
6.55 |
4.97
6.55 |
2.48
3.43 |
5.19
6.55 |
2.59
3.43 |
2.70
3.43 |
5.41
6.55 |
0.25 KVA |
KVA AMPS |
4.33
5.20 |
3.78
5.20 |
4.26
5.20 |
8.32
10.40 |
4.56
5.20 |
8.70
10.40 |
4.76
5.20 |
9.08
10.40 |
3.96
5.72 |
7.092
10.92 |
8.28
10.92 |
4.14
5.72 |
8.64
10.92 |
4.32
5.72 |
4.51
5.72 |
9.02
10.92 |
0.5 |
KVA |
8.60
10.40 |
7.56
10.40 |
8.52
10.40 |
16.64
20.80 |
9.11
10.40 |
17.40
20.80 |
9.51
10.40 |
18.16
20.80 |
7.93
11.44 |
15.85
21.84 |
16.57
21.84 |
8.28
11.44 |
17.29
21.84 |
8.64
11.44 |
9.02
11.44 |
18.04
21.84 |
0.75 |
KVA |
12.90
15.60 |
11.34
15.60 |
12.77
15.60 |
24.97
31.20 |
13.67
15.60 |
26.10
31.20 |
14.27
15.60 |
27.24
31.20 |
11.89
17.16 |
23.77
32.76 |
24.85
32.76 |
12.42
17.16 |
25.93
32.76 |
12.96
17.16 |
13.52
17.16 |
27.07
32.76 |
1 |
KVA |
17.30
20.80 |
15.12
20.80 |
17.03
20.80 |
33.29
41.60 |
18.23
20.80 |
34.80
41.60 |
19.02
20.80 |
36.31
41.60 |
15.85
22.88 |
31.70
43.68 |
33.14
43.68 |
16.57
22.88 |
34.57
43.68 |
17.28
22.88 |
18.03
22.88 |
36.09
43.68 |
1.5 |
KVA |
25.90
31.20 |
22.69
31.20 |
25.55
31.20 |
49.93
62.40 |
27.34
31.20 |
52.20
62.40 |
28.53
31.20 |
54.47
62.40 |
23.78
34.32 |
47.55
65.52 |
49.71
65.52 |
24.85
34.32 |
51.86
65.52 |
25.92
34.32 |
27.05
34.32 |
54.13
665.52 |
2 |
KVA |
34.60
41.60 |
30.25
41.60 |
34.07
41.60 |
66.58
83.20 |
36.46
41.60 |
69.60
83.20 |
38.04
41.60 |
72.63
83.20 |
31.70
45.76 |
63.40
87.36 |
66.27
87.36 |
33.13
45.76 |
69.15
87.36 |
34.56
45.76 |
36.06
45.76 |
72.18
87.36 |
3 |
KVA |
52.00
62.50 |
45.45
62.50 |
51.18
62.50 |
100.03
125.00 |
54.69
62.50 |
104.57
125.00 |
57.07
62.50 |
109.12
125.00 |
47.63
68.75 |
95.25
131.25 |
99.57
131.25 |
49.77
68.75 |
103.89
131.25 |
51.92
68.75 |
54.12
68.75 |
108.44
131.25 |
5 |
KVA |
86.10
104.00 |
75.62
104.00 |
85.17
104.00 |
166.44
208.00 |
91.15
104.00 |
174.01
208.00 |
95.11
208.00 |
181.57
208.00 |
79.26
114.40 |
158.50
218.40 |
165.69
218.40 |
82.83
114.40 |
172.87
218.40 |
86.39
114.40 |
90.16
114.40 |
180.44
218.40 |
Number
|
3 | 2 | 2 | 2 | 2 | 2 | 2 | 2 | 2 | 2 | 2 | 2 | 2 | 2 | 2 | 2 | |
|
E | G | G | H | G | H | G | H | G | H | H | G | H | G | G | H |
![]() Figure A
|
||
![]() Figure B
|
||
![]() Figure C
|
||
![]() Figure D
|
||
Figure E
|
||
Figure F
|
||
Figure G
|
||
Figure H
|
||
Figure J
|
||
Figure K
|
||
Figure L
|
||
![]() Figure M |