On Fri, 21 Aug 1998, Harold Hallikainen wrote:

>         So, the consensus seems to be that new CE regulations REQUIRE a
> circuit breaker switch both the hot and neutral?  The product here is a

I think that there is a loophole in the regulations for the case where you
also have a 'main' fuse for a number of circuits. In this case, the 'main'
fuse must be a DPDT breaker and the individual circuit fuses can be
singles only. I think that there is a limit on the Amps on the 'main' vs.
the Amps on each circuit for this. I have seen a lot of systems done like
this and having CE stamps on them. As I said, the neutral fuse is for fire
protection mainly, in fixed installations.

> and solid state relays, which then drive the load.  Loads are connected
> between an output terminal block (driven by the SSR) and a "neutral bar"
> that ties all the load neutrals to the incoming line neutral.

imho, you should take a good look at the design to find out what can
happen to it if it is connected to a delta supply instead of Y (or Y with
missing ground). This kind of thing happens often in 3rd world countries
as local electricians determine the null and the earth on the spot (no
schematics ;( ) and the neutral and earth can be reversed. Also don't
count on the phase order being right, if you need that ;( ;(.

> finding the two pole breakers that will fit where the existing single
> pole breakers fit.

imho, take a look at Euro suppliers (Siemens ?). I think that there is a
rail-mount breaker design that has the 2 pole pairs stepped to fit in the
same width (looks like: OX[ C ]XO where O-O is the 1st pole, X-X the 2nd,
[] are the edges of the top and C is the breaker reset flap). I think it's
by Siemens. Not sure.

>         I realize this is considerably off topic, but this is the only
> list I'm on devoted to design and with such an international audience.
> It's great!

Usenet newsgroups are probably a better address for this questions, as
some real experts from the standards institutions proper occasionally read
in and answer questions...

>         On another international topic, several of my PIC designs are
> powered by 12VDC, 500mA "wall warts" with a 2.1mm center positive DC
> plug.  We get calls from dealers wanting a 230VAC 50Hz input wall wart.
...

Well, there is a booming business in replacement wall warts here. Some can
be fitted with an adapter, but most are thrown and changed for a local
one. Some firms go as far as to deliver units without wall warts and have
a local firm franchised to sell wall warts separately for their product.
For better products, workers replace the wall warts and fit local ones.

I have seen so many blunders on the part of overseas shippers of equipment
that we usually plan for a local supply just in case. In general, web
catalogs cannot be trusted unless they give an engineering drawing with
physical dimensions. The best way is to obtain a sample of the
target animal and use calipers.

hope this helps,

Peter