MTRAB® 2.5 DB100

with alpha-control

Fields of application:

  • Tap changers
  • Arc suppression coils (Petersen coil)
  • Air-filled cable terminal boxes
  • Traction transformers

Silica gel fill level: 1,1 kg
with α-control


The MTRAB® 2.5 DB100 with alpha-control is a condition-controlled system, recommended for use on tap changers, arc suppression coils, air-filled cable terminal boxes and traction transformers. The desiccant is regenerated depending on the condition.

Good to know

The main function of dehydrating breathers is to dehumidify the ambient air. As a result of the thermal compression of the insulation medium, the ambient air flows from the environment to the expansion tank of the transformer and tap changer (referred to as inhalation). During inhalation, moisture must be prevented from penetrating into the equipment with the air flow, as this reduces the insulating effect due to the contamination of the insulating medium.

This reduction of the dielectric strength of the insulation medium leads to massive malfunctions in the operational sequence. This could even result in the equipment being destroyed. When the flow is reversed from the expansion tank of the transformer and tap changer to the environment (referred to as exhalation), there must be no significant flow resistance that blocks the flow.


The devices of the MTRAB® 2.5 series regenerate the silica gel via sensor control through installed heating elements. This eliminates the periodic visual inspections normally needed; the cost-intensive, regular replacement of the used desiccant is completely eliminated.

In ongoing operation, the air flowing to the oil conservator is directed across the silica gel desiccant and thereby dried through optimized flow control. The humidity of the air in the piping is measured constantly using a sensor. If the humidity level (%rH) of the air in the piping exceeds a standardized value, the regeneration process (heating the silica gel) is activated. The water vapor escaping from the silica gel condenses and drips out of the stainless steel filter installed in the bottom section. An additional sensor monitors the controller and the correct operation of the heating elements. An optional heating unit for the output filter prevents escaping condensation from possibly freezing in Arctic regions.

Integrated data logger / MTRAB® MSET software

Der MTRAB® 2.5 ist standardmäßig mit dem Datenlogger der neuesten Generation ausgestattet (optionale Software erforderlich).
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Integration into SCADA and ETOS®

The device can be integrated easily into ETOS® (Embedded Transformer Operating System) with the optional Modbus RTU. Furthermore, it can be integrated into a SCADA system or control room at any time via the analog and digital interfaces.