screwits

[tonyelectric]

Hi Everyone

I'm new to the forum and have a burning question, but first a bit about me I'm a working commercial/industrial/domestic spark in the UK and also do a fair amount of appliance repair work.

Now we all know the little ceramic screwits that went out of favor in the late 70s (I think), however several wholesalers are now selling the US designed version which is plastic with a metal core, they are not new to me as appliance manufacturers and neon sign makers have been using this version for years.

I contacted the NICEIC who simply said if its BS/CE approved thats OK. Now i'm not looking to use any but am curious as to whether the screwit was ever actually outlawed (i'm only 31 so if they were it was before my time) or is it just an urban legend?

Incidently I got hold of a couple of the new version and put them through their paces on the bench, they out performed chock block and crimps with regard to current carrying/resistance and operating temp.

Be interested in your views

 

[Chri5]

Are those the older version of these plastci things ?

Ceramic based ?


Thing being that all terminations need to be enclosed in a box and plate, or a connection box cover.

I can't imagine anyone have a suitable box for them that would be discrete (as in size).

Wago cover up to 6mm

http://www.tlc-direct.co.uk/Main_Index/Cable_Accessories_Index/Wago/index.html

 

[Lectrician]

That pic is of Line Taps.

Commonly used to tee one cable into another without cutting the cable (simply strip it).

Screwits are screwed onto the end of a bunch of twisted conductors, commonly seen inside older light fittings.

 

[PrinceofDarkness]

Hello Tony, and welcome to the forum (not that it's my place to do so

Yes, those old 'Screwits' (or 'wire-nuts' as the Americans call them, were (and are still) highly dependable for joining (stranded) wires.

No, they weren't 'outlawed' as such, by any Regulation, but the thing is that all joints to exposed cores of a sheathed cable need to be enclosed within an insulated enclosure. Those 'Screwits' aren't very good at joining solid (unstranded) wires - that's why they died an unnatural death.

But, they still live on in 'NEMA Standard' electric motor terminal enclosures, where their resistance to vibration is legendary (unlike the hard-wired European machine terminal blocks).


Lucia

 

[Wangerman]

Haven't seen the old ceramics for years we used to call them dog cocks

 

[tonyelectric]

Thanks for the replies, the new type plastic and metal screwits are available at CEF and others. They are pretty swish with soft grip wings (same finish they use on screwdriver handles) which makes them pricey (over a £ with the 70% or so account discount each) so not really viable yet, but I think a handful might be useful for toolbox use to make temporary joins for example in testing.

Princeofdarkness comments confirm my thoughts that they are a good product if used properly, i've had a mail back from the manufacturers who confirm they are fully approved, rated to 600V (currents vary on size) and are apparently standard equipment on aircraft for electrical connctions thanks to the vibration resistance.