Login to your account

Username *
Password *
Remember Me

Create an account

Fields marked with an asterisk (*) are required.
Name *
Username *
Password *
Verify password *
Email *
Verify email *
Captcha *

Why do Transformers Explode?

Transformer after explosion and fire Transformer after explosion and fire

Transformers are equipped with standard protections, but they still explode and lead to fire.

This phenomenon is generally due to an internal short-circuit in the transformer. The short-circuit, created by an insulation failure, reaches 1,200-degree Celsius. It vaporizes the oil located in the transformer tank.

The oil, being in contact with very high temperature, vaporizes and creates explosive gases. Within milliseconds, it creates a Dynamic Pressure Peak traveling at the speed of 1,200 meters per second. The pressure propagation can be compared to a storm for which you hear the sounds after some time, while it propagates in the air.

Being in a closed area, the pressure wave will reflect off the transformer walls, coils and all other obstacles, leading to complex waves. These complexes waves create a static pressure, which often reach 10 bars (150 psi). The transformer tank generally cannot withstand more than 1.2 bars (18 psi). With the pressure being constant in all the transformer, the transformer will rupture.

The explosive gases generated during the short-circuit will be in contact with oxygen and the oil contained in the transformer, which leads to an explosion and associated fire.

The total sequence mentioned above happens in around 200 to 400 milliseconds, for which standard protections are not designed to react.

Ads_nfpa_850

We use cookies

We use cookies on our website. Some of them are essential for the operation of the site, while others help us to improve this site and the user experience (tracking cookies). You can decide for yourself whether you want to allow cookies or not. Please note that if you reject them, you may not be able to use all the functionalities of the site.