Product Description


TT3 Series

Isolating Transformer

Fixing rail, PRI 3 x 400 Vac, 3 x 690 Vac, SEC 3 x 400 Vac, 1,000 - 30,000 VA


  • Very good corrosion protection and low noise thanks to BLOCK IMPEX vacuum impregnation
  • Multi-functional mounting brackets with 12 slots
  • Secondary side ±5% tappings for voltage adjustment
  • Integrated crane eyes
  • Enlarged mounting bracket for easy installation from above
  • Fixed, contact protected screw connection terminals complying with UVV BGV A3
  • Safe galvanic isolation
  • Patented assembly technology to lower heat losses


Isolating Transformers

Isolating transformers with galvanic isolation provide a reliable supply to circuits with the safety measures “protective separation”. The transformers provide double or reinforced isolation between the primary and secondary sides. Any requested network configuration is possible for the secondary side, whether this involves a monitored isolated system or grounded system with fuse elements. The output voltage for the isolating transformers can be between 50 Vac and 1,000 Vac or 120 Vdc and 1,415 Vdc. BLOCK's standard range includes power outputs of up to 1 MVA.

  • Double or reinforced isolation between the primary and secondary sides
  • Flexible structure for the secondary side network configuration
  • Power output: 50 Vac to 1,000 Vac or 120 Vdc to 1,415 Vdc
  • Power output: up to 1 MVA, higher power ratings upon request


Isolating transformer for the safe electrical isolation of the input and output sides. The transformer may be used to set up protective separation as a protective measure in accordance with VDE 0100.


Rated Power

1,000 - 30,000 VA


Up to 97.5 %

Maximum Ambient Temperature

50 °C


Class F

Degree of Protection

IP 00 or IP 23 Optionally adapted package for higher degrees of protection

Rated Output Voltage

3 x 400 Vac

Rated Input Voltage

3 x 400 Vac, 3 x 690 Vac


VDE 0570 Part2-4, DIN EN 61558-2-4, EN 61558-2-4, IEC 61558-2-4, UL 5085-1/-2, CSA 22.2 No.66


UL 5085-1/-2, CSA 22.2 No.66

Specifications vary between configurations. Refer to the Configurations below for more information and links to the manufacturer's website.


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