Transformer Rating Improvement (Uprate)

Invariably a transformer can have its rating, or capacity, improved on site at a nominal cost compared to buying new. The minimal outage time required to complete the works also makes the total project a cost effective and highly efficient option when the load is increasing on a network.

Rosh Engineering has vast experience in improving transformer rating on site by carrying out transformer rating enhancement (uprate) by altering the cooling on site using radiators, fans, pumps and heat exchangers.

A full assessment of the transformer is done and full calculations complete with temperature rise assessments giving a re-certification of the new rating.

The Scope Includes the Following:

1. Feasibility study
2. Thermal design calculations
3. Design, supply and install new cooling
4. Dismantle and disposal of old cooling
5. Design, supply and install cooling control schematic systems

Advantages of On-site Transformer Uprate:

1. Improved transformer capacity
2. Extended transformer life (depending on load cycles)
3. Shorter transformer down time and interruption
4. Lower costs and investment compared to new replacement transformer

Rosh has uprated more than 300 transformers throughout UK, Europe and South America. The transformer ratings range from 500kVA – 600kVA 11/0.415kV up to 330MVA – 360MVA 400/19kV.

Average rating improvement – 38% (subject to feasibility)

Average age of transformer when uprated – 39 years

Oldest transformer when uprated – 52 years old