ECN Forum Forums General Topics of the Trade General Discussion Area Double insulated?

Sven, I have a 6-month-old DVD player with a linecord having no characteristic SPT-cord "grooves" between the 2 conductors. It must be a version of the NISPT-2 material. It seems like it will be more durable than what has long been conventional "zip cord".

It seems I remember two changes in US appliance cords. The more recent was increasing overall cord-insulation thickness—I believe there is some history of child injury from toddler “bitethough”.

An earlier change was increasing the dimensions of the skirt around the molded-plastic blade base on cord caps, to limit the chance of children’s smaller fingers contacting blades while energized. {My first 120V jolt from sticking fingers between cord-cap blades too many years ago is seared in my memory. It is my first recollection of being in immediate pain with no one else around—it didn’t make sense that I could really hurt from such an innocent act.}

Minor Aside — At http://ulstandardsinfonet.ul.com/catalog/testequippics1.html — notice the “UL Articulate Probe” and “IEC Flexible Test Finger”. [Note item prices (!) at http://ulstandardsinfonet.ul.com/catalog/testequip.html ]

I say we chuck all those 'double insulated' toys in some occupied Taiwanese hot tub

Sparky,

could you explain that comment?

Sven,

interesting info. It made me look up the HAR (European) and UL cords. Here are the specifications from a manufacturer:

H03VVH2-F vs. NISPT-2
Conductors: 2x0.75 mm2 vs. 18 AWG
Insulation thickness 0.5 vs. 0.73 mm
Jacket thickness 0.6 vs. 0.4 mm
Dimensions: 3.5x5.7 vs. 3.5x7.0
Rated voltage: 300V vs. 300V
Temperature: 70°C vs. 60°C or 105°C

(NISPT-1 is identical to NISPT-2 except for the insulation thickness being only 0.34 mm.)

The total insulation between the user and the copper is 1.1 mm in both cases. What makes the NISPT-2 wider than the HAR cord is that the conductors are thicker than the jacket. (I find it a bit counterintuitive to make the conductors thicker instead than the jacket when you make a thougher cord. But it makes sense if your starting point is SPT-1 and SPT-2.)

Question: What is the 105°C rated cord used for?

(The HAR cord is available in 90°C, but with a different designation.)

I have seen SPT2 on florr lamps, and SPT-1 on table lamps (ones bought a set, that was the case).

In our A/V system, with relatively new
components, except the TV, the newer components use the NISPT-2 cord, which have a black and white conductor inside

I think Steve is making a statement about the amount of cheap & nasty Far Eastern junk that's sold in our stores these days.

Black and white? Wow. I'm surprised that it doesn't come with brown and blue conductors -- I thought the USA was also migrating to harmonized cordage. And considering that most of the stuff (right down to the cordsets) comes from the Far East, you'd think they'd be using harmonized.

I've got a couple of tape-recorder cordsets from the dollar store here that are wired with H03VVH2-F -- with USA style male plugs molded on the end...

I'm echoing discussion that's already taken place in the color-code threads in the non-U.S. area, but this is really one area where I don't see any need for the U.S.A. to change at all just to be "harmonized" with the "Rest of the World."

right on Paul.......

especially since we've our own cheap/nasty junk