VAX 4000 Power Cord (BA440) - test-drb@ccmp.vtda.org

4 Sep 2001

On Sep 4, 17:17, Eric Dittman wrote:
...
  > > I remember a couple of months ago there was
discussion on
 > > the proper cable for a BA440 power supply (normal North
 > > American three prong power cord but with a notch where it
 > > plugs in to the power supply).  Was there a consensus on
 > > the designation (and any place in the US that sell them)? 
...
  > > Dave McGuire &lt;mcguire(a)neurotica.com&gt;
wrote:
 >   Here is a copy of a message I sent on 7/22/2001 about this:
 >
 >   They're are three power connectors in the "standard" family as
defined
...
   by IEC...a
low-, medium-, and high-current version.  The low-current
 version is the one we're all used to, 10A.  The one on some MicroVAX
 chassis is the 15A version.  The third is a larger one (20A, I think
 but I'm not sure) that has three flat pins in a triangular arrangement
 but in two parallel planes, with a plain rectangular body.  Tey're
 found on some larger Cisco routers (7513 for one) and on SGI
 Challenge-L systems for example. 
 Dave, do you happen to have the IEC spec number? 
It's IEC 320, which is in several parts; you probably want Sheets C13, C14,
 C19 and C20.

I should point out that the current ratings used in the United States are
different for those used in Europe.  Also that the current rating depends
on the type of cable, not just the connector.  Many of the power cords
built to the spec are rated at 5A or 6A (6A was the original spec for the
common IEC 320 *connector* but it was uprated a few years ago) because the
*cable* in them is only rated for that much.  The ordinary connectors are
rated for use at temperatures up to 65 Celcius, and are sometimes called
"cold condition" connectors.

The version with the notch (keyway) is called a "hot condition" connector,
and in Europe it's still only rated for 10A.  However, hot condition
connectors are made of materials able to stand a higher temperature and are
used for things like electric kettles.  They're rated for operation at up
to 120 Celcius.  In the States the connector is rated for 16A (again,
assuming the cable itself is rated that high).  The original intent was not
to provide a higher current rating but a higher operating temperature.  It
just so happens that things that get hot (kettles) tend to use a lot of
current to do so :-)

The third version has the three pins all parallel in the same horizontal
plane (ie, 90 degrees around from the others), and is slightly larger.
 It's rated at 16A in Europe (and for 20A in the States, I believe) but
only up to 65 Celcius.

-- 
Pete						Peter Turnbull
						Network Manager
						University of York