MACRO   Power & Engineering
 
THREE PHASE AUTOTRANSFORMERS
Autotransformers are economical and effective alternative to Isolation transformers but are limited in application. The size and cost of the transformers can often be reduced dramatically by combining the input and output windings. They are ideal for small voltage reductions and can be single or three phase. We offer expert guidance when considering this configuration, including safety, wiring rules, and more importantly cost saving. 
Low losses due to reduced size
Long Service life (no maintenance, extremely high reliability )
Reliable performance (cool, quite operation –no fans or moving parts)
Rugged construction and conservative ratings
Highest Insulation level - class ‘H’
Excellent regulation and High efficiency 
High power density
Low magnetic stray field
Excellent load weight ratio
Standard secondary voltages at full resistive load.100 % duty cycle (continuous operation) 
Recommended total load is 20 to 100% of the VA rating
Screw terminals blocks for current less than 50A, higher current on secondary may require bus bars at the discretion of Macro Power.
Short circuit protection requires external fuse, circuit breaker etc
All Enclosures (indoor, outdoor, encapsulated etc ) available for Isolation transformers are also for auto transformers 
Installation:
Transformers must be protected by either a primary or secondary fuse
Final 100% Testing:
High Voltage
Winding Short Circuit
Open Circuit Secondary Voltage
Voltage Ratio

Note: Due to continual product improvement data and specifications are subject to change without notice.
3 PHASE AUTO TRANSFORMER 415V TO 200, 220 OR 240V
RATING DIMENSION-OPEN TYPE MASS
KVA HEIGHT WIDTH DEPTH KG
1 120 240 150 7
2 120 240 200 12
3 145 290 200 21
4 145 290 250 24
5 185 380 250 30
7 185 380 250 33
10 300 310 300 42
15 320 310 300 60
20 350 310 300 70
25 350 310 300 85
30 420 350 300 100
35 390 350 300 110
40 390 350 300 120
45 420 380 300 135
50 460 380 300 145
55 460 400 300 160
60 460 420 330 170
65 460 420 330 180
70 480 450 350 190
75 480 450 400 200
80 550 550 450 250
90 550 550 450 280
100 600 600 450 320
125 600 600 450 400
150 620 620 500 450
200 620 620 500 530
250 650 650 500 580
300 650 650 500 650