Unmatched Safety: HTT Cast Resin Transformers

HTT cast resin transformers with C5, E4 and F1 certification

Maximum operational reliability for HTT cast resin transformers

All cast resin transformers from HTT meet the strictest requirements in terms of temperature, ambient conditions and fire load. This is confirmed by the certifications according to classes C5, E4 and F1 by the CESI testing institute in Milan following type tests in 2023. Cast resin transformers are classified into different fire, climate and environmental classes in accordance with international standard IEC 60076-11 (8/2018).

HTT cast resin transformers therefore offer the highest possible operational reliability that can currently be demanded.

C5, E4 and F1 certifications at a glance

Climate class*: The climate class takes into account the lowest ambient temperature during transport, storage and operation. HTT cast resin transformers are assigned to class C5 with an ambient temperature of up to -60°C during transport and storage and a temperature of up to -50°C in operation. In comparison, the lowest ambient temperature of class C1 is only -25°C during transport and storage and -5°C during operation. The temperatures can be agreed on a project-specific basis.

Environmental classes*: The variables of humidity, dripping water, condensation, temperature and contamination determine the ambient conditions for cast resin transformers. HTT achieves class E4 in this category, which allows frequent condensation or heavy soiling as well as a combination of both influences. No condensation on the cast resin transformer and negligible soiling according to class E0 is usually achieved when installed in a dust-free and dry interior.

Fire classes*: The fire class provides information about the fire load in the event of a fire in the vicinity of the transformer and the development of toxic and visually obstructive smoke gases. HTT cast resin transformers fulfil the requirements of class F1, which requires a limitation of the fire hazard. The release of toxic substances and visibility-impairing smoke must be minimised.

*Source: IEC 60076-11 (8/2018)