The 15 amp power board is utilised for network equipment drawing high-current, such as for blade servers and a large uninterruptible power supply (UPS). Furthermore there are rack mountable UPS units and other larger network IT equipment in datacentres requiring 15 amp power rails. To distinguish the 15 amp plug from 10 amp plugs the earth pin is over-sized and longer than the power pins. For example, to ensure sockets accept plugs of equal or of a lower current capacity, but not of higher capacity. The Australian Standards for electrical plugs are stipulated by AS/NZS 3112:2011.
Example of 15 amp power rails (see below):
As a general guide the maximum allowable lengths of extension cords used are (see below):