Hering VPT - Model ISODRY Series -Online Transformer Insulation Drying Systems

HERING prides itself on the number of transformer treatment options that it offers its business partners. The ISODRY Series is focused specifically on moisture removal, particularly from the paper insulation in the transformer core. The harmful effect of water on the transformer dielectric strength is generally well-known and appreciated and there are a number of solutions that address that. The ISODRY® Series, and its vacuum based complement, TIDO, reduce aging effects on the cellulose insulation by continuously removing water – unattended.

The HERING ISODRY online transformer insulation dry out systems do not require the use of vacuum equipment and rely on an adsorbent molecular sieve media that will not absorb oil but will remove – and hold – moisture from the oil. Dry oil is hygroscopic and when circulated back to the insulation after passing through the columns, adsorbs moisture from the paper insulation in a dynamic process. A low- speed oil pump circulates the oil continuously or in user-determined operation cycles. Inlet and outlet inline hygrometers constantly measure the water removed and indicate both locally and remotely when there is a need to replace the media in the columns. Change-out is rapid and with each column able to hold around 3.5 kg of water, infrequent. The ISODRY® represents a modern solution to an age-old problem and comes with state-of-the-art options including remote monitoring, control and access, bright, local readout using Siemens state- of-the-art HMI and vivid graphics that allow for instant ease of understanding. A comprehensive monitoring and alarm system complete the package.

Continuous online removal of moisture and gas from solid insulation and oil

• Based on extensively proven technology
• Easily installed on energized transformer
• Temperature, moisture and transformer condition monitoring available
• Robust design for long lifetime
• High quality steel piping
• All components from Western brand manufacturers
• Numerous safety features for protection

Online drying your transformers with the ISODRY® Series grants:

• Benefits for new transformers – moisture content can be kept below the original factory level, thus protecting the transformer from day 1
• Benefits for older or wet transformers – Continuous drying over several months brings down moisture & gas content to acceptable levels for extended lifetime
• Effective moisture removal for oil & paper – ISODRY® ensures lowest possible moisture within transformer oil and insulation material
• Insulation drying for vacuum-rated and non-vacuum-rated transformers – The moisture removal takes place within the equipment transformer vacuum tight ISODRY® without affecting the operation
• No downtime due to transformer overhaul – operated on energized transformers as effectively as on un-energized transformers