3 Phase Autotransformer for vertical mountingDAS 0.1 - 2.0kVA according to IEC/DIN EN61558-2-13

overviewtechnical dataPDF data sheet

Typical applications

3 phase autotransformer according to IEC/EN61558-2-13 for general applications without the need of a galvanic isolation, e.g. for transforming typical mains voltage to other voltages needed by tools, machinery or other devices.

Autotransformers do not provide any electrical protection due to the lack of galvanic isolation between input and output windings.


3 phase transformer according to EN61558-2-13. protection class I ready. Due to innovative vacuum impregnation in polyester varnish, the noise level is extraordinary low. Screw terminals are contact proof according to BGV A3.

Autotransformers are provided for a voltage range from 100 V up to 550 V (special voltage versions on request).
Standard switching matrix: Yan0 (typical star load approx. 10%). If typical star load should reach rated current, switching matrix Zan0 is used.

Please add switching matrix requested when ordering the transformer. For further information, don´t hesitate to contact us.

3 Phase Autotransformer for vertical mounting

with screw type terminals IEC/EN61558-2-13

Voltage range input / output100 V … 550 V
Rated frequency50/60 Hz
Power range100VA … 1,6kVA
Output designSchaltgruppe Standard YNa0

Sternpunktbelastbarkeit ca.10%

Schaltgruppe auf Anforderung ZNa0

Sternpunktbelastbarkeit 100%

Max. ambient temperature40°C
UL Insulation System (optional)OBJY2.E181051
Insulation class (IEC85)B 130°C
Fire protection classUL94HB (V-0 possible)
Degree of protectionIP00
Protection classI ready
  • No galvanic isolation
  • Ready for vertical mounting – including angle brackets
  • Transformer connections: Screw terminals according to A3
  • Transformer completely vacuum impregnated
approx. mm
SizeType and
Ordering No.
0,101206511090394,8×9,00,601,803UI 60/21DAS0010
0,161207511090494,8×9,00,802,403UI 60/31DAS0016
0,2515073132113495,8×11,01,303,903UI 75/26DAS0025
0,4015088132113645,8×11,01,605,703UI 75/41,5DAS0040
0,5018080157136567,0×13,02,206,603UI 90/31DAS0050
0,6318090157136667,0×13,02,808,003UI 90/41,5DAS0063
0,80180100157136767,0×13,03,009,903UI 90/51,5DAS0080
1,0023092202176717,0×13,04,6013,503UI 114/40DAS0100
1,2523092202176717,0×13,05,3014,203UI 114/40DAS0125
1,6024591207185719,0×13,05,7015,303UI 120/41DAS0160

Please note

* Dimension “C” indicates a reference value only. Phase current and therefore size of screw terminals used depends on transformer ratio (identical size). Several coolant bores between primary and secundary winding. Number and position of coolant bores depend on transformer ratio and size.

Explanation and vector-groups to applicate 1 phase and 3 phase autotransformers

Autotransformers do not provide galvanic isolation.

They have electroconductive connection between input and output winding. It`s not allowed to take autotransformers for electrically protective separation.


If difference between input voltage and output voltage is small:

  • mains power may be higher
  • transformed power is lower
  • size can be reduced (core, copper winding)

Since the high-voltage and low-voltage windings in an autotransformer share a common portion of the same winding, the size and material costs can be reduced.

Example shows 90% power saving compared to an isolating transformer

Equation to calculate the requested size

Example: 1 phase autotransformer / Input voltage 440 V / Output voltage 400 V / „Rated power“ needed for application 5 kVA

Identical equation works with 3 phase transformers.





Regarding input/ output “upper“ or „lower voltage“ is independant, voltage related only for 3 phase autotransformers value of phase voltage is important.

Standard circuit design of 3 phase autotransformers is YNa0. Max. load at neutral wire is approx. max. 10% of nominal current (phase current).

If 100% neutral wire load is requested, circuit design ZNa0 is manufactured.

Note: YNa0 design can be used in certain circumstances, if neutral wire at input provides full load and transformer star point is permanently connected to load. Please contact us for further informations!