VIMAP RCID is on load dry-out unit designed for continual unattended operation on energized power transformers
Dehydration is done by circulating the transformer oil through columns with granular synthetic adsorbents that attract water molecules and permanently bonding them to the active surface within the pores. By this procedure, the insulating oil is dried in a few hours or days. However, the drying of cellulose insulation is a far slower process.
By maintaining an imbalance of moisture content between oil and cellulose, with continuous oil drying, water diffusion from wet cellulose insulation to dried oil is achieved, thus removing moisture from deeper layers of solid insulation.
99 % of water in power transformer is stored in cellulose insulation
1 % of water is in the oil
Preventive maintenance
Corrective maintenance
Field of Application
New or previously dried power transformers- continual maintenance of low moisture level in both oil and cellulose insulation.
Transformers with increased content of moisture – reduction of moisture in complete insulation, improvement of insulation characteristics, increase of power transformers safety and its lifetime


No oil heating – no undesired effects from oil heating on overall oil quality
No oil vacuuming – no other parts to maintain or protect – longer equipment lifetime
No oil inhibitor removed
No dissolved gasses removal
Adsorption of water molecules
