Actually there are some configurations that are not used any more. 2-15, 2-20, and 2-30 are basically unheard of anymore. 1-15 plugs are very common. 1-15 receptacles can still be found in older instalations but are becoming more rare. As for the other 2pin connectors, ouside of a few combination 1-15/2-15 recepticals I have never even seen any. There are also a few more nonstandard proprietary connectors that are not shown, yet are still seen commonly in industry. Hubbell's Hubbelock is one example. You see it used in hospitals for portable Xray machines and in a few industrial settings.
[This message has been edited by IanR (edited 10-18-2005).]
One thing I like about the NEMA flat-blade configurations is the interchangability where appropriate.
For example, a 5-15 receptacle will accept a 5-15 plug or a 1-15 plug (either the polarized or the non-polarized variety) A 5-20 receptacle will accept the appropriate 5-20 or 1-20 plugs, and the 5-15 and 1-15 types as well. Ditto for the 6-xx 240V versions.
Under the old round-pin BS configurations there was no such compatibility. We had both 2-pin non-grounding and 3-pin grounding versions of 5-amp plugs, for instance, but a 2-pin non-grounding 5A plug would not fit a 3-pin grounding 5A receptacle.
To complete the picture on the IEC309 connectors, the other two most commonly used configurations are:
2P+E 240V, used widely in industry for general-purpose single-phase loads, and the 16A version is virtually universal for campsite electrical hookups for RVs and travel trailers:
2P+E 110V, used for our low-voltage building site power tools on a center-tapped 55-0-55V system:
[This message has been edited by pauluk (edited 10-18-2005).]
We're supposed to use the blue 16A fittings for ALL outdoor sockets. BS1363 with weather-proofing isn't allowed by the regs. Directly connected to a 16/20A radial or, if it's a ring... connect via a local fuse (e.g. a 13A spur located inside) (RCD required as per all >32A socket outlets)
The weather-proofed BS1363 sockets do appear in outdoor domestic installations, but a contractor's not supposed to install them. They're sold by the likes of B&Q ... as are cooker control switches with a socket (also banned by the regs here)
Here's the quote from the ETCI's FAQs for consumers.
Q: Are there special plugs and sockets for outdoor installations and if so why? A: Yes. We like most mainland Europe countries do not consider indoor plugs to be suitable for outdoor installations subject to weather and rough handling and so ordinary 13A sockets to I.S. 401 are not suitable for outdoor use. Like all socket outlets up to 32A, they should be protected by an RCD. The Rules require that outdoor sockets and industrial sockets comply with IS/EN60309 standard. In this system both the plug and socket are hard wearing and are deemed to be suitable for outdoor use. The single phase plug is coloured blue and the socket is inclined towards the ground to prevent the ingress of moisture. They may be more cumbersome than the flat pin plug system but they are safer.
(They're blaiming mainland european practice for their overkill regulations - yet I don't think very many Mainland European countries actually enforce anything quite so strict - then again there are parts of the west of ireland where it can rain horizontally for 7 days or where you can get a type of misty rain "mizzle" that requires ships deck fittings to be 100% safe
[This message has been edited by djk (edited 10-20-2005).]