Joe T sent me a link to a UK Electrical Safety Page. I thought it would be interesting to discuss things found there.
http://www.angliacampus.com/education/fire/secondar/electric.htm






Bill

a pix is worth a 1000 codes

The ground pin opening the other two is a neat idea for childproofing outlets.

Some good ideas here, except that in the US someone would probably defeat the overcurrent protection by inserting a solid piece of wire or other metal in place of the fuse.

The color coding is very interesting too!

QUESTION:

Where in the NEC can a light blue grounded conductor be used??

If my memory serves me right, Leviton makes a receptacle that works the same way.

Joe,
You can use light blue anywhere you want to as long as its not for grounding or grounded conductors. I think that you are looking for an answer that states 504-80(c). This section is permissive and does not require the use of light blue. It is also a very poorly written section. Does, "and where no other conductors colored light blue", mean that if I choose to use light blue for intrinsically safe circuits, I can't use light blue anywhere else in the structure?
Don(resqcapt19)

Well, well, well.... The trusty British 13-amp plug!

I was going to mention the shuttered sockets at some point, but it looks like you've beaten me to it! The shutters have been a feature of the outlets since they first appeared some 50 years ago. Shutters were also adopted on the older round-pin outlets as well.

Some of the latest sockets have adopted a different shutter mechanism which isn't operated from the earth pin. Instead, they rely on equal pressure at the live & neutral to open; pressure on just one leaves it firmly closed. Definitely trickier for inserting test probes!

The cord colors are those I mentiond some time ago. We adopted them for flex in 1970 as part of a European standard, but retained the old colors (red, black, green) for fixed cables. The green has since be changed to green/yellow for earth though.

The fuses at each plug provide good protection for individual appliances, but I'm afraid that many people don't understand their significance. A lot of folk always put in a 13A fuse "because it's a 13A plug." I don't see many with the fuse clips bridged with wire though.

All told, it looks like a safer arrangement to me, for say...daycare receptacles.

Joe article 400-22(c).Where does a 120v 15 or 20 amp recepticle have an orange wire hooked to the white screw?

The fact that kids might poke things in outlets is the main point put forward in favor of the shutters. If you consider that our pins are much thicker than those on U.S. plugs, then the range of metal objects which could otherwise be inserted is much greater. The hot side is a full 240V to ground of course, so it would pack quite a jolt.

For several years now it's been possible to buy molded plastic blanks with plastic pins which fit into an outlet. I guess the theory is that kids would be slowed down even more by having to remove that first.

I understand that these blanks are now required to be fitted in unused outlets in certain places, including daycare. IEE Regs. are mandatory in many public buildings, but this rule isn't from the IEE.

Apparently it's from a new amendment to the Healh & Safety at Work Act or one of the other similar gestapo-like depts.

I've done a couple of daycare centers, and we have used shuttered receptacles for the kid's rooms. Also we applied for, and received, code variances to allow us to install them at +54", which would normally be in conflict with the Americans with Disability Act (ADA). I think they're a great idea for defeating the curious tikes' attempts at self-electrocution

I seem to recall seeing something about standard heights in residences being 48" for wall switches and 18" for receptacles (except worktops, of course).

Am I about right here, or am I imagining things again?

Yes those are about "standard", but they're only guidelines...

I place Switch boxes at 48-1/2" to top of the box (on 8 ft ceilings) and Recepts Boxes sit on top of the hammer which puts them at about 18" to top of the box.

Counter top recepts are 45" to top of box.

Sparky66,

48-1/2"? Don't the sheetrockers complain? At 48-1/2", wouldn't they have to cut both sheets? The rockers that I have worked with have always prefered that I measure down from the ceiling 48" to the top of the box, that way they are guaranteed to only need to cut the bottom sheet. Of course building methods vary so much from location to location, just curious.

Matt

If you measure 48-1/2" from the top plate or the sub floor, you will get precisely the same location as 48" from the finished ceiling if they use 1/2 drywall...

48-1/2" from the subfloor makes it so the drywallers cut only three sides of one piece.

So, we're talking about the same thing.



[This message has been edited by sparky66wv (edited 08-30-2001).]

I like the protected plug arangement, I wish similar devices could be implemented here for sub-1800W loads (and subsequent lightweight cords) on 15 and 20 Amp circuits...

It would save lives...

gestapo-like depts

We have those too!

...see i have this theory about the DA cuttin' a deal @ Nuremburg......

That's probably the biggest advantage of the 13A fused plug, although the best protection relies on Joe Average knowing the right size fuse to fit. I see clocks, bedside lamps, etc. with 13A fuses in their plugs all the time.

At least people bridging the fuse clips with wire/kitchen foil is rare. Just as well considering that in most cases the fuse at the panel is 30A. 7.2kW could make the cord on a bedside lamp light up real pretty!