DIRECTIONS FOR THE USE OF A THREE PHASE AUTOTRANSFORMER

 Execution in self-ventilated epoxy painted metal enclosure
 Protection class
 Temperature class
 Protection class
 Resin impregnated and tropicalised winding

 Please follow the table below to get the best performance from our three phase autotransformers. The table shows the max. rating available on each output voltage at a rated ambient temperature of 25°C. Please note that for a correct operation of the transformer, the max current applied should be not over the 80% of the max rating shown on the table. This would allow to always protect the transformer from instant over-charge, keeping temperatures at the right level, and will guarantee the longest life to the transformer itself.

Power

out 220V

out 380V

out 450V

out 480V

5kVA

13 A

7 A

6 A

6 A

10kVA

26 A

15 A

12 A

12 A

15kVA

39 A

22 A

19 A

18 A

20kVA

52 A

30 A

25 A

24 A

25kVA

65 A

37 A

32 A

30 A

30kVA

78 A

45 A

38 A

36 A

40kVA

104 A

60 A

50 A

48 A

50kVA

130 A

75 A

64 A

60 A

60kVA

156 A

90 A

76 A

72 A

80kVA

208 A

120 A

100 A

96 A

100kVA

260 A

150 A

128 A

120 A

150kVA

390 A

225 A

192 A

180 A

200kVA

520 A

300 A

256 A

240 A

300kVA

780 A

450 A

380 A

360 A

500kVA

1300 A

750 A

640 A

600 A

Tables shown are just an example. Ratings can always be calculated according  to these instructions and the voltage indications on the label of the transformer

HOW TO CHOOSE THE CORRECT TRANSFORMER FOR A SINGLE EQUIPMENT

Ratings one appliances are indicated in “KW”, while ratings on transformers are always shown in “kVA”. There is a relation between “kVA”  and “KW” (or “HP”) which can vary for any single appliance. The relations shown below are just a reference and must be verified with the distributor of the equipment connected to the transformer or on the related instructions:

PUMP                                       KVA= KW / 0,6

AIR CONDITIONING SYSTEM       KVA= KW / 0,7

MOTOR                                    KVA= KW / 0,8

SODIUM-DISCHARGE LAMPS       KVA= KW / 0,9

TUNGSTEN LAMPS                    KVA= KW

ELECTRICAL RELATIONSHIPS

 KW = HP / 0,735

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