Full Remote Control

Very Low Power Consumption

Fully Controlled Transformer Dryout


Transformer Moisture Management Systems

Expiotech transformer moisture management systems (MMS) enable transformer operators to measure the moisture in the insulation of a transformer, to remove moisture as required and to maintain the moisture at low risk levels, all with the transformer remaining in normal service.

The internet based process monitoring the control system allows full remote control. Moisture measurement and dry-out processes reports are available.

Various models and variable flow rates suit all transformer sizes.

System Description

The MMS is designed to remove dissolved water from oil in tansformers, using Velcon Superdri Filter Technology, while the transformer remains energised and in service.

This reduces the total moisture content of the transformer insulation. In order to determine the amount of moisture to be removed, the system has an Evaluation mode, whereby the moisture content of the insulation is determined. The system is then switched to Filtration mode and moisture is removed to a predetermined final moisture content.

Web based remote control and monitoring.


  • On-line operation without the risks associated with vacuum plants.
  • Does not remove dissolved gas and affect dissolved gas analysis.
  • Does not affect the oil properties e.g. aromatic content, oxidation inhibitors.
  • No complicated machinery: easy to operate and maintain. Unattended operation.
  • Very low power consumption. Variable flow rate to suit transformer size on request.
  • The control system and software allow:
    • Measurement of the moisture content of the transformer insulation.
    • Dry-out process control and monitoring.
    • Measurement & Dry-out process reporting.
    • System status and alarms sent via email or to selected cellular telephones.

Resulting in a fully controlled transformer dry-out.

Alternative filter cartridges may be fitted to reduce the oil acidity level and dissolve compounds or remove particulate.