Power Circuits, ring and radial?

A "ring" circuit is a series of receptacles wired in parallel. The "ring" is intended to make outlets

easily accessible to a limited number of devices from numerous points, and not to increase the number of electrical devices which can be plugged in. A radial circuit makes the capacity of its wiring

and breaker available at a single outlet. An electric water heater is an example off a device with

such a large demand as to require a radial circuit with a dedicated outlet.

Outlets are often wired in rings because they are now required at 6 foot intervals (in some jurisdictions) to help avoid the use of extension cords. Almost all air conditioners are required to have

a radially wired, dedicated outlet because of their power requirements.

Regulations - pretty much in the UK it is the BS7675, IEE Electrical Wiring Regulations covers all installation methods really.

Sockets: Ring circuit

Water Heater: Radial Circuit