T 4.62 Use of inadequate power outlet strips

There are usually not enough fixed electrical outlets installed to operate all equipment required. Power strips are then usually used to compensate for the lack of outlets. Such power outlet strips, when of insufficient quality, are a dangerous ignition source due to

• poor contacts
• contact springs that are too weak
• a lack of strain relief
• use of wires with conductors that are too small
• overvoltages

and are therefore a significant fire hazard.

When several small power strips are connected in series to provide enough outlets for all equipment, the risks due to small conductors and overvoltages increases even more.

If the power strips are placed on the floor in a workspace, then they are also often subject to mechanical stress due to being kicked or stepped on, or bumped into by vacuum cleaners, etc. Due to the lack of stress relief and poor contacts, this can quickly lead to contact resistances, overheating, and finally to a fire. Furthermore, power strips are a tripping hazard when simply placed loosely on the floor.

Example:

In a branch office of an insurance company, a smouldering fire started due to a defective power strip purchased privately by an employee. Employees had connected a fan heater to the power strip in addition to the PC and printer already connected. While the fan heater was left on accidentally at the highest setting during a company meeting, the housing of the overloaded power strip started smouldering and charred.