Auto transformer is the transformer that only contains one winding. When it is used as step-down transformer, please pull part of wire out from winding as secondary winding. When used as step-up transformer, please add applied voltage only on part of the wire turn.

Usually, the winding that belong to both primary and secondary winding is called as common winding, the rest are series winding. Under the premise of same capacity, compared with common transformer, auto-transformer features small size, high efficiency. It shows obviously under greater transformer capacity and higher voltage. So, along with the development of electric power system, the improvement of the voltage class, the increasing of transmission capacity, auto-transformer has been used widely because of the large capacity, small loss.

Advantages: two winding overlaps partly to save some copper wire; small volume, simple structure.
Disadvantages: we can’ t separate the primary winding with the secondary wholly, it will be dangerous among the step-down lines and will cause the VOUT rise as the primary widing if the secondary breaks suddenly.

Specification	Capacity (KVA)	Nominal Voltage		Size of Transformer (cm)	Shell Size (cm)	Weight (kg)
		Primary (V)	Secondary (V)
ZSG-120KVA	120	380V or according to customer' s requirement	According to customer' s requirement	700*320*660	1000*500*1050	465
ZSG-150KVA	150			700*320*670	1000*500*1050	600
ZSG-180KVA	180			750*350*680	1000*500*1050	745
ZSG-200KVA	200			750*350*680	1000*500*1050	865
ZSG-250KVA	250			750*350*680	1000*500*1050	945
ZSG-300KVA	300			850*370*680	1200*650*1150	1160
ZSG-320KVA	320			850*370*680	1200*650*1150	1260
ZSG-350KVA	350			950*450*830	1200*650*1150	1400
ZSG-400KVA	400			950*450*830	1200*650*1150	1550
ZSG-450KVA	450			950*450*830	1200*650*1150	1700
ZSG-500KVA	500			950*450*830	1200*650*1150	1850