[Test-Equipment] old oval power cords

[gil smith]

Mark and gang:

Hmm.  I could be wrong, but I think the "non-standard" 17952 power cord is
indeed the one for older HP (and Fluke) gear.

If you go to http://www.volexpowercords.com and search for 17280 (the
"international" standard UL817 cord), it shows an end view of the connector
-- if the ground pin is up, the line/hot pin is in the lower-right.  The
Volex page for the 17952 cord does not show its diagram, but it is just
swapped hot/neutral.

I only have one oval cord at the moment, and it is apparently one of the
17280 "international standard" cords.  So, I popped the top on my HP 5233L
(the only old-cord HP unit I have), and it looked like the opposite
polarity was needed.  Since things like this can be confusing when just
looking (and mirroring a plug), I plugged the 17280 cord into the 5233L.  I
measured nothing from the chassis ground to the fuse/switch side of the
receptacle, but 120V from chassis to the other pin.  So this is the wrong
cord, and poses a shock hazard when working on the inside of the box.  My
old Fluke 8100A uses the same wiring on its oval receptacle.  These are the
only two old-cord units I have, but I presume that all their gear would be
wired the same.  Which is an odd choice, since they shipped stuff
world-wide, and I can't imagine they would have different wiring on export
gear.  I wonder how many service guys died because of this?

The hanford.gov site you included below says they also used the
"non-standard" cord, which would be the same as the HP...

Anyway, this means, as far as I can tell, that the "non-standard,
North-American" 17952 power cord is the proper one.  Unless someone knows
something else.  I have some of the 17952 cords on the way from Allied, and
I'll let you know if the polarity is as expected.

Things shouldn't be this complicated (or dangerous)!

gil



At 01:56 PM 1/16/02 -0500, you wrote:
>Gil, I believe the 17280 cord is the proper one to use.  The 17952
>has the non-standard polarity.  Check out the page:
>
>    http://www.hanford.gov/lessons/sitell/ll96/96i005.txt
>
>for more details.  Although it is possible HP has the same issue :-)
>
>BTW, Volex bought the power cord division from Belden.  The HP
>cords were originally made by Belden.  Also, Newark carries the
>cords, and I believe Mouser does as well.  You may also be able
>to pick these cords up at an electrical supply house, because I
>believe the 17280 is an industry standard number.
>
>FWIW  :-)
>
>73
>
>- Mark  N1VQW
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