Safety changes after Perth explosion

More safety precautions have been put in place for the type of high-voltage switches involved in a fatal shopping centre explosion in Perth.

Irish national Alan Cummins, 30, was killed instantly in the blast on February 3 at the Morley Galleria shopping centre.

Matthew Hutchins, 22, died hours later in hospital after suffering burns to 80 per cent of his body.

Two of their colleagues were also seriously burnt but survived.

The four workers were carrying out maintenance near an electrical transformer when the explosion occurred.

Energy Safety previously issued an order for Long and Crawford Manchester switchgear, but on Tuesday, it extended the order to all high-voltage oil-insulated combined-fuse switches.

Director Ken Bowron said while the investigation was not yet complete, it appeared that there had been a short circuit fault in the switch tank after the rupture and disintegration of a high-voltage fuse in the unit.

"In addition to banning the opening of the lid, I have now also banned the commencement of any electrical work on this type of equipment, including operation of the switching or earthing mechanisms if a high-voltage fuse has operated," he said.

The new order will be sent to all licensed electrical contractors in WA and property owners likely to have these switches on their property.