In 2012, the PSA reviewed reported incidents from the period 2001-2012, and contracted Sintef to carry out a study with an analysis of causal relationships and measures associated with this type of incident.

The data basis for the study was 35 investigation reports selected by the PSA, as well as information from seven interviews with skilled professionals (those responsible for electrical installations) from the involved companies.

Triggering and underlying causes

The objective of the study was to identify the triggering and underlying causes of incidents involving fires in electrical installations, as well as proposed measures, as described in the investigation reports. Causes and measures were divided into the categories Human, Technology and Organisation (HTO). The handling of the incidents as regards preparedness was also assessed based on the investigation reports.

The mapping shows that the Technology category dominates among triggering causes (85% of the 35 incidents). The most important triggering causal factors are random technical equipment fault (44%) and technical condition/age/wear (35%). The most frequent point of origin is transformers (9 of 35) and contactors (7 of 35).

Recurring factors

Technical causes also constitute a large portion of the underlying causes. Recurring factors include deficient earth fault protection, deficient overcurrent protection and degraded insulation as a result of high temperature.

As regards the preparedness handling of incidents, it emerges that it is challenging to shut down power to the installations before starting extinguishing efforts. Furthermore, in several of the incidents, there are ambiguities in connection with counting personnel present in the installation. Six of the investigation reports reported significant preparedness deficiencies.

Promote learning

The risk of fire appears to be particularly great during the start-up phase of new installations, as well as installations commissioned following a re-build or modification.

The PSA intends to use the analysis results to promote continuous learning and improvement in the industry in order to avoid hazard and accident situations which may result in loss of human life, personal injuries, pollution or loss of financial assets.

The report is available in Norwegian only.