C5-, E4- and F1-Certification of our cast resin transformers

According to IEC 60076-11 (8/2018) casting resin transformers are used in different fire,
Climatic and environmental classes. HTT casting resin transformers are certified according
to classes C5, E4 and F1: Appropriate type tests were carried out in the summer of 2023 at
the CESI testing institute in Milano (Italy).

 

With these certifications, HTT cast resin transformers meet the strictest
current requirements in terms of operational safety.

 

Climate Classes**
The climate class takes into account the lowest ambient temperature during transport,
Storage and operation.
                                            class C1      Class C2      class C3       class C4      class C5     class Cxy*
transport&storage              -25°C         -25°C           -40°C          -50°C          -60°C          -x°C
operation                                    -5°C         -25°C           -25°C          -40°C          -50°C          -y°C
* The temperatures –X°C and –Y°C can be agreed on a project-specific basis.

 

Environmental Classes**
The quantities of humidity, drip water, condensation, temperature and pollution
determine the environmental conditions for casting resin transformers.
class E0:
Condensation does not occur at the transformer, the pollution is negligible.
This condition is usually observed when installed in a dust-free and dry environment.
class E1:
Occasional condensation may occur at the transformer (e. g. transformer is switched off).
Contamination to a limited extent is possible.
class E2:
Frequent condensation or light pollution or a combination of both.
class E3:
Frequent condensation or medium pollution or a combination of both.
class E4:
Frequent condensation or heavy pollution or a combination of both.

 

Fire Classes**
The fire class specifies the fire load in case of a fire in the vicinity of the transformer
and the development of toxic and obscuring flue gases.
Class F0:
There is no specific fire risk to be taken into account. The release of toxic substances
smoke and visual impairments must nevertheless be reduced to a minimum.
Class F1:
Limitation of the fire hazard is necessary. The release of toxic substances and
smoke that obstructs vision must be reduced to a minimum.

 

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