I know the 15/20A 2+E standard plugs, and i've seen several more bigger ones. is there a web page or does somebody have an image of the bigger systems with some details?


If wanted, i can get up some pictures of our 3L+N+E plug system "CEE" (aka cekon).

http://www.quail.com/nema.cfm

whow!
does anyone look through this?
why so many?

To distinct between all the formats.

IMO, they could have made some configurations backwared compatible, like the French 3P+N+E
20A plug in another thread, so you an attach certain applianced in a "universal" outlet,
and have "universal" Plugs. I know for a fact
though, that Eagle Cooper sells a multi-spec plug (has removable prongs), that can do at least NEMA 5-50, 6-30, and 6-50

Andy,

there are equally many versions of the CEE plugs. Most of them you never see.

It's pretty easy to see why: 4 sizes (16, 32, 63, 125) and three different number of pins (3, 4, 5) and twelve different voltage/frequency configurations for each. This sums up to 144 different plugs. Of course, many of these have no specified use and are not manufactured.

There was a thread on this last year:
https://www.electrical-contractor.net/ubb/Forum9/HTML/000127.html

i knew about the lot of the cee plugs, but most of them are uncommon.

Common are mainly the 2+E blue one for 230V 16A heavy industrial equipment, camping sites etc. and the 3+N+E red one in 16, 32 or 63A for nearly all 3Ph Appliances, building site panels ect.

I havent seen any 3ph+E without neutral cee's. There are some but i cant figure out where to use them right now. When we power a 3PH delta motor, we always use the 3LNE system and leave the N unconnected.


Wjich ones are the most common US plugs out of all of these?

[This message has been edited by :andy: (edited 01-03-2004).]

Most common receptacle - domestic

5-15 General purpose (mostly duplex; one over the other)
1-15 Obsolete but common on old properties
5-20 Mainly dedicated equipment (mostly single; furnace, pump etc)
6-20 Workshop; air conditioners *
10-30 Dryer (old)
10-50 Stove (old)
14-30 Dryer (new)
14-50 Stove (new)
rare are 6-30 and 6-50 for welding machines

Most common plug – domestic

1-15 Most equipment is class2 (including metal jacketed toasters!)
5-15 Class 1
6-15 240V stuff *
then as above

Note that the connectors for 30A and above are about 1.5 times the size of those 20A and below so what appear to be similar geometries are not. Most installations have the ground pin at the bottom – a source of passionate debate on the other forum.

Bjarney et al. may be able to enlighten you on the industrial side.

* I'm using a personal based example and normally these would be only slightly more common than the welders


[This message has been edited by Hutch (edited 01-03-2004).]

There are a few typos in the Quail chart: “30 250V” “30 120/208V” should read 3ø 250V 3ø 120/208V, but are close to obsolete for lack of a grounding pin. OTOH, there is a completely different set of US/NEMA locking wiring devices, that are a bit more common in commercial/industrial applications. Also, I have seen in places like McDonald’s [cardboard] Hamburgers—rugged, often “washdown duty,” circuit-interrupting pin-and-sleeve devices, that fit the IEC309 series 2 dimensions.

One thing I like about the NEMA 15 and 20A configurations is th neat way they allow acceptable mating combinations and restrict others.

For example, the 5-15 receptacle will accept either a 1-15 or a 5-15 plug, and a 15A plug will also fit a 20A outlet but not vice versa.

The old British (BS546) connectors had no such compatibility: A 2-pin, non-grounding 5A plug would not fit a 3-pin grounding 5A socket due to different spacing (the shutters being another problem).

Here is a chart of NEMA locking devices.

but the cable onthe 15A plug then is not properly protected anymore
or are these made for 20A?

PaulUK:

The BS546 system seems to be the only one with complete incompatability between plug ratings.

Most European countries also employ a variety of plugs with ratings of less than 16A all of which usually fit their 16A sockets.

e.g. Europlug fits Schuko 16A outlets as well as small 2-pin 6 and 10A outlets. However, Schuko plugs won't fit into the lower rater outlets as the pins are fatter.

The Italian system allows the 10A plug to be plugged into the 16A outlet but not the other way around.

BS546 was just weird.. i think it had a lot to do with the use of very thin flex on lamps and radios in the UK coupled with the IEE being a little over conservative.

In reality 2A and 5A plugs were rarely connected to 2A or 5A circuits as they were used with adaptors on 15A circuits.

Good point about the Europlug/Schuko etc. I believe that the smallest flex size specified in most of Europe is 0.75 sq. mm, whereas in the U.K. we also have 0.5 used on some small devices (or a near equivalent in pre-metric days). This has certainly gone on for many years, and I don;t like to think about how many old table-lamps were wired to BS546 plugs on 15A circuits with such thin wire.

Andy,
The NEC in the U.S. allows 15A receptacles to be fed from either a 15 or a 20A branch circuit.