Special thawing transformer AT400 is suited for thawing frozen water pipes AT400 according to IEC/DIN EN61558-2-6

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Proved technology for every day use! Special thawing transformer AT400 is suited for thawing frozen water pipes.Transformer is constructed for longevity and vacuum impregnated.
Not suitable for copper pipes!

Instructions of use

  • Clean connection points of frozen pipe for AT400 grippers
  • Place the AT400 on a dry, non-combustible underlay. Connect gripper wires firmly to AT400 device.
  • Fix the grippers tightly to the frozen pipe section
  • Put the switch to “OFF” position.
  • Now connect the AT400 to a grounded Schuko type socket for mains power supply
  • AT400 switch offers 4 level operation (Level 0 = OFF, Level 1 = WEAK/SLOW, Level 2 = MEDIUM, Level 3 = HIGH) –
  • At any level, current indicator should not exceed 15 A. In this case choose a lower level.
  • Note: AT400 automatically switches off, if current is permanently > 15 A.
  • Current flow warms water pipe, the ice inside the pipe is melting.
  • AT400 should be used in dry environment only. Thawing procedure should be monitored at any time.


  • Robust housing
  • Transformer with copper winding

4 Level thawing current control:

  • Level 0 = OFF
  • Level 1 = WEAK / SLOW
  • Level 2 = MEDIUM
  • Level 3 = HIGH


  • Overload protection
  • Long operation mode
  • High thawing current
  • Large grippers
  • Long gripper wires
  • Large wire gauge
  • Ease of use
  • Device made in Germany

Included in delivery

  • Special thawing transformer AT400 will be delivered operation ready for immediate use.
  • Power cable with Schuko type plug, 3.5 m long. Gripper wires, length 2 x 10 m.

1AC Safety Transformer according to  IEC/EN61558-2-6

Order-No. 74706A
Mains input voltage 230V
Input power 3,4kVA
Rated frequency 50/60 Hz
Thawing voltage max. 8,0V
Thawing current max. 450A
Slow-blow fuse 16 A inactive
Switch-on time 40% at max. Power
4 Level operation 0=OFF / 1=WEAK-SLOW / 2=MEDIUM / 3=HIGH
Ambient temperature ± 0°C
Cooling method S (self-cooling)
Insulation class (IEC85) B 130°C
Degree of protection IP21
Dimensions for thawing clamp ½ to 2 inch
Dimensions LxWxH 400 x 180 x 280 mm
Weight transformer approx. 24,50kg
Weight welding cable approx. 12,00kg