To allow for the safe side-by-side use of devices with integral mains pins (such as plug-in power supplies) in double or multiple socket outlets (double-power points or power boards), these devices must be either less than 43.8mm wide or greater than 54mm wide. Two power supplies that are both less than 43.8mm wide will fit into a double power point (or adjacent sockets on a power board) without jamming.
Two "wide" power supplies (both wider than (54mm) cannot be plugged into the same double power point (neither power supply will work). If one "wide" and one "narrow" power supply are plugged into the same double power point, only one power supply will be able to be correctly inserted and the other power supply will not work. The width (w) is measured at the widest part of the device as shown above.
Two narrow power supplies may be used together in a standard double power point. They will both safely operate without mechanical interference.
In an attempt to use one wide plus one narrow power supply in the same double power point, only one will be able to be fully inserted and the other power supply will not work. This example shows the "wide" power supply displacing the "narrow" power supply and preventing it from operating safely.
This example shows an attempt to use two "wide" power supplies in the same double power point. Both the power supplies are displaced, neither can be inserted correctly and neither power supply will operate safely.