Assignment For Badge

[securespark]

I am organising another project for the scouts.

This time, a simple "wire a plug" type assignment.

Thelads are 10 1/2 -14 yo.

Flex I have, plug tops I will have to buy.
I will strip the flex ready.

Any tips for cheaply making multiple lengths of flex safe at one end against inadvertant energisation?

I also want to furnish them with a leaflet. First, instructions on how to wire a plug from a kosher source such as the ESC. Plus, a brief history of how our plugs and sockets came to be, why the earth pin is longer, why the shorter ones are sleeved, why fuses are different sizes etc....

Anything I've missed?

Thanks guys.

 

[ban-all-sheds]

Any tips for cheaply making multiple lengths of flex safe at one end against inadvertant energisation?

Either don't have fuses in the plugs, or have ones which have blown?

Anything I've missed?

Why some people say plug top when they mean the whole plug?

 

[JohnD]

new plugs usually come with a card showing core lengths, stripping, colours. Can you teach them to read the card and follow it?

Why not let them do the stripping and trimming? Maybe after sccessfully wiring one you've prepared?

See if you can find some Duraplugs where the flex has to go through the cover before connecting. I've seen where people have forgotten to do that and have cut the cord restraint to get the top on

 

[flameport]

Any tips for cheaply making multiple lengths of flex safe at one end against inadvertant energisation?

Use these http://www.rapidonline.com/Cables-Connectors/Adhesive-Lined-Heat-Shrink-End-Cap-15-0-4-5-03-1991

 

[securespark]

Thanks guys:

Ban - I thought of that while away from here. I thought how much fun it would be putting a load of 3A fuses in a 3kW fan heater to pop them off.....

Flame - wonder if I can get these (or something like it) from WF?

John - nice idea. But then I need multiple pairs of cutters and gloves....

 

[JohnD]

surely they use their teeth?

 

[OwainDIYer]

Any tips for cheaply making multiple lengths of flex safe at one end against inadvertant energisation?

As well as heatshrinking the other end, I would put the live pins through a spanner and bend them so they cannot fit into a socket. And document that you have done so in your risk assessment.

Edit - bend ALL pins, and count the pins out and back again at the end of the session, to guard against anyone taking a pin home and playing with it - or it getting lost in the hall and found by the playgroup.

You may already know of this case
http://www.scotcourts.gov.uk/opinions/2011FAI17.html
but it's a warning.

You could incorporate some of the visual elements of electrical appliance testing - e.g. unsleeved pins, exposed cores, cracked plug or appliance case, etc. Iron flexes are good for demonstrating as they're often fabric covered and subject to a lot of rubbing damage.

Local charity shop might let you have unsafe appliances which they can't sell - or your local fire safety officer might have some demo ones you can borrow.

There used to be Public Safety films about not using appliances with matchsticks instead of plugs - they'll be on Youtube probably. [/u]

 

[securespark]

You know I have to fill in a risk assessment form to do this.......??



Another query.

Having just nosied on the ESC website, they now say there are only two main fuse sizes for plugs: 3A & 13A. 3A up to 700W. 13A over 700W.

What about the rest?

What ratings are now given to the others?

I mean, in the good old days,

1A = up to 240W

2A = -480W

3A = -720W

5A = -1200W

7A = -1680W

10A= -2400W

13A = -3120W

But, using 230V does not give 700W. So they have rounded it up. But what formula have they used?

 

[securespark]

Somebody put a link on DIYnot a while back to the IET's article about the history of the RFC - can anybody put their hands on a link to it, please?

 

[plugwash]

On the subject of fuse ratings BS1363 says that for 0.5mm flex 3A is the maximum rating that should normally be used (with an exception allowing use of a 5A fuse with non-rewirable plugs for equipment with high inrush currents) and that with all other flex sizes in the table a 13A fuse is acceptable.

Afaict 3A and 13A were the traditional ratings of plug fuses, 5A also became fairly common at some point. The other ratings securespark lists are available from some wholesalesrs and component vendors but have never been common.

As for the power rating on the ESC site I would assume they were rounded after calculation. .

 

[OwainDIYer]

http://scouts.org.uk/documents/bandqresource/BNQ badge scouts part 2.pdf

 

[Tech99]

Afaict 3A and 13A were the traditional ratings of plug fuses, 5A also became fairly common at some point. The other ratings securespark lists are available from some wholesalesrs and component vendors but have never been common.

Back in the early days of BS1362/1363 the recommended "standard" ratings were 2, 5, 10 and 13A. Gradually it was considered that this represented too large a number of choices for the average domestic user, the 10A was dropped, and 3A was substituted for the 2A, with 5A still remaining common.

Today, 13A fuses are brown, 3A red, with all the other "non standard" values (1, 2, 5, 7, 10A) generally black. But those older types were different colours to reflect their recommended usage of the time. I think 2A was blue originally, but blue was certainly used for 3A fuses before red became the norm. 5A were grey, 10A yellow. 13A were brown right from the start.

The BS646 fuses rated up to 5A max. used in some BS546 plugs were completely different.

 

[securespark]

Plug:

Yeah, BGB says 0.5 is 3A, 0.75 is 6A, 1.0 is 10A and 1.25 is 13A.

Puzzled as to why 1363 allows 13A with 0.75 and above, although I must admit, I've seen a few new appliances with 13A fuses in with 0.75 flex, like fridges small electric fires etc...

Owain, yeah, got that link, thanks!!


Tech, have seen fuses different colours, but I think they were 646, not 1362.

 

[Tech99]

Tech, have seen fuses different colours, but I think they were 646, not 1362.

You have to go back a good few years for the different colour BS1362 types. I remember MK fuses being 3A blue & 5A grey maybe into the late sixties or early seventies, before 3A became red and 5A was dropped as a recommended value. (Hard to remember which were new fuses at that time and which were older ones from the sixties still in use). Yellow for 10A would have already been dropped before that time.

 

[TicklyT]

Any tips for cheaply making multiple lengths of flex safe at one end against inadvertant energisation?

Use some appliance leads with moulded on IEC connectors on t'other end? Maybe stuff some silicon sealant into the pin holes in the IEC connectors for good measure?
Make some dummy fuses from, say, a piece of wooden doweling?

You could tell the lads the lead they are working on is for, say, a 1 KW appliance, mark several dummy fuses up with a variety of nominal values, and ask your candidates to select an appropriate fuse for their project.