Searching \ for '[ot] International Power' in subject line. ()
Make payments with PayPal - it's fast, free and secure! Help us get a faster server
FAQ page: www.piclist.com/techref/power.htm?key=power
Search entire site for: 'International Power'.

Exact match. Not showing close matches.
PICList Thread
'[ot] International Power'
1998\08\20@181404 by Harold Hallikainen

picon face
       I've got a customer asking us to use a two pole circuit breaker
to handle single phase loads on a 230VAC three phase Y (or star) system.
I would expect them to put the load between a line and neutral, with a
breaker only in the line side of the circuit (at least that's what we do
here in the US, but this is for Jordan).
       It APPEARS they want to use a two pole breaker with one pole
breaking the hot, the other the neutral.  Is this done?  Anyone in
Jordan?

Thanks!

Harold




Harold Hallikainen
spam_OUTharoldTakeThisOuTspamhallikainen.com
Hallikainen & Friends, Inc.
See the FCC Rules at http://hallikainen.com/FccRules and comments filed
in LPFM proceeding at http://hallikainen.com/lpfm

_____________________________________________________________________
You don't need to buy Internet access to use free Internet e-mail.
Get completely free e-mail from Juno at http://www.juno.com
Or call Juno at (800) 654-JUNO [654-5866]

1998\08\20@184736 by mwalsh

flavicon
face
Harold Hallikainen wrote:

{Quote hidden}

Harold

We recently had some equipment re-checked by UL.  To get CE
compliance to export to Europe, we had to change the color coding
on the primary side from black, white, and green to blue, brown,
and green with a yellow tracer.  We also had to add a fuse to the
neutral side of the primary power.  We keep our UL and CSA
approval with this new color code and extra fuse.

This is medical equipment certified to IEC 601-1.  I don't know
if the additional fusing is needed for all types of equipment but
I suspect this sort of thing will become the defacto standard for
equipment that may be exported.

Mark

1998\08\21@002744 by g.daniel.invent.design

flavicon
face
Hi Harold,

if the nutral breaking contact fails, then apliance fails with all
circuitry at 230vac, makes it more dangerous to service.  remember that
amatures *will* fiddle.

regards,
Graham Daniel.

Harold Hallikainen wrote:
{Quote hidden}

1998\08\21@021837 by Nigel Goodwin

flavicon
picon face
In message <.....19980820.151419.2791.0.HaroldHallikainenKILLspamspam.....juno.com>, Harold
Hallikainen <EraseMEharoldhallikainenspam_OUTspamTakeThisOuTJUNO.COM> writes
>        I've got a customer asking us to use a two pole circuit breaker
>to handle single phase loads on a 230VAC three phase Y (or star) system.
>I would expect them to put the load between a line and neutral, with a
>breaker only in the line side of the circuit (at least that's what we do
>here in the US, but this is for Jordan).
>        It APPEARS they want to use a two pole breaker with one pole
>breaking the hot, the other the neutral.  Is this done?  Anyone in
>Jordan?

I don't know about Jordon, but it's fairly common in the UK. Generally
light switches only switch the live conductor, and switched mains socket
only switch the live. But most seperate switches, for such things as
emmersion heaters, electric showers, storage heaters switch both live
and neutral.
--

Nigel.

       /--------------------------------------------------------------\
       | Nigel Goodwin   | Internet : nigelgspamspam_OUTlpilsley.demon.co.uk     |
       | Lower Pilsley   | Web Page : http://www.lpilsley.demon.co.uk |
       | Chesterfield    |                                            |
       | England         |                                            |
       \--------------------------------------------------------------/

1998\08\21@055608 by Paul BRITTON

flavicon
face
Some time back I worked for a telecomms test equipment manufacturer, and
they double fused (live & neutral) every thing *BUT* any thing that was
sold to British Telecom had to have the neutral fuse removed (and linked
directly)....something to do with making sure the equipment wasn't still
live if only the neutral fuse failed I think.

1998\08\21@071413 by Morgan Olsson

picon face
At 09:56 1998-08-21 +0000, you wrote:
>Some time back I worked for a telecomms test equipment manufacturer, and
>they double fused (live & neutral) every thing *BUT* any thing that was
>sold to British Telecom had to have the neutral fuse removed (and linked
>directly)....something to do with making sure the equipment wasn't still
>live if only the neutral fuse failed I think.
>

Yes, that is good for appliances that have guaranteed polarity.

But if it is not guaranteed, like if a rotatable contact is used, or the
standard don't specify which is live, or an amateur connect a wire wrong,
then it might be the supposed neutral that is live.  And in that case it is
good to have a fuse and breaker there, in case of short to chassis...

/Morgan

/  Morgan Olsson, MORGANS REGLERTEKNIK, SE-277 35 KIVIK, Sweden \
\  @spam@mrtKILLspamspaminame.com, ph: +46 (0)414 70741; fax +46 (0)414 70331    /

1998\08\21@083316 by cousens

flavicon
face
Harold Hallikainen wrote:
>
>         I've got a customer asking us to use a two pole circuit breaker
> to handle single phase loads on a 230VAC three phase Y (or star) system.


On a live/neutral system
In the US and UK  99.9% of the time you can be sure that live IS live
and neutral IS nuetral

However ...........  in less developed countrys ?
there are not always colour standards
(expecially where they also import German equipment they use/used black
for live)
So live / neutral reversal is commom (If it works why change it)

On a three phase system

ie: An unsecured three phase cable suppling your machine and an ajacent
machine
gets pulled, the neutral gets disconected (Did you really think they
would run a cable just for your machine ?)


ie: At a distribution box (one of many on the customers site)
that was intended to supply 50 Amps, now running at 120A
(and it's 80c in the box, it's could easily be 45c in the factory in the
summer)
The cable supplying power to the box, which has not been screwed down
properly
or has worked loose due to thermal cycling,  one phase starts sparking,
burns the insulation, flashes over to the neutral, destroys that phase
and neutral wire, before burning the 125 Amp fuse that should have been
a
50 Amp fuse

I see this type of damage regulary

Fit a two pole switch

Peter Cousens
email: KILLspamcousensKILLspamspamher.forthnet.gr  phone: + 3081 380534
snailmail:  Folia, Agia Fotini, Karteros, Heraklion  Crete, Greece.

1998\08\21@090034 by paulb

flavicon
face
Nigel Goodwin wrote:

> in the UK.  Generally light switches only switch the live conductor,
> and switched mains socket only switch the live.  But most seperate
> switches, for such things as immersion heaters, electric showers,
> storage heaters switch both live and neutral.

 The philosophy behind this hinges on the likelihood of wiring
modifications being made and service being performed using only the
local switch for isolation.  "Fixed" wiring is expected to have active
(live if you like) and neutral irrevocably defined, and the neutral is
known to be bonded to ground, so only the active need be isolated.

 Once the appliance has a flexible cord connecting it to an outlet (or
even a wiring box), there«s a chance that the cord will be damaged and
rewired, possibly by an unqualified person.  Without the guarantee of
which wire is which, you must isolate both.  The same applies to circuit
breakers and it is very reasonable of them to isolate both lines if
tripped.

 Neutral fuses are in much the same situation.  If there is any chance
the supply polarity be reversed, then the neutral fuse becomes the
active fuse and will be blown if a short to ground occurs.  Because this
is at that time effectively the active fuse, the situation is safe.  It
may become unsafe when moved out of the fault location for service but
well, if you are testing something with a blown fuse you don«t just plug
it in and turn it on.  *Do* you?

 By the way, a little commonsense here suggests the active fuse be
rated between 70% and 50% of the neutral, so it blows preferentially for
internal overload while the neutral *only* blows for a ground short.  (I
say *commonsense*; the standards may say different for all I know!)
--
 Cheers,
       Paul B.

1998\08\21@092740 by Peter L. Peres

picon face
On Fri, 21 Aug 1998, Graham Daniel wrote:

> Hi Harold,
>
> if the nutral breaking contact fails, then apliance fails with all
> circuitry at 230vac, makes it more dangerous to service.  remember that
> amatures *will* fiddle.

You are right, but the neutral fuse is a fire protection measure in case
current from somewhere else comes through the apparatus (such as,
lightning). The GFCI in the panel, which is mandatory. takes care of the
situation that you describe.  The new CE rules require the fuse on neutral
apparently. BTW GFCIs used here and in Europe are DPDTs, and break the
neutral too according to the hieroglyph on the one near me here.

Peter

1998\08\21@093531 by Caisson

flavicon
face
> Van: Paul BRITTON <RemoveMEPaul.BRITTONTakeThisOuTspamMMSUK.CO.UK>
> Aan: spamBeGonePICLISTspamBeGonespamMITVMA.MIT.EDU
> Onderwerp: Re: [ot] International Power
> Datum: vrijdag 21 augustus 1998 11:56
>
> Some time back I worked for a telecomms test equipment manufacturer, and
> they double fused (live & neutral) every thing *BUT* any thing that was
> sold to British Telecom had to have the neutral fuse removed (and linked
> directly)....something to do with making sure the equipment wasn't still
> live if only the neutral fuse failed I think.

It's an error punishable by death (electricity does not forgive mistakes)
to switch the ground-line only (by single-phase switch or fuse).  Only when
the Phase(s) is(are) disconnected a Nutral-line could (but mostly should
not) be disconnected.

Nothing is as dangerous as a device that apears to be off, but is connected
to the life-wire everywhere.  Here (in the netherlands) it's illegal also
to switch the nutral-line other than together with the life-wire.

Greetz,
 Rudy Wieser

1998\08\21@095157 by Mike Keitz

picon face
On Fri, 21 Aug 1998 16:24:48 +1200 Graham Daniel
<TakeThisOuTg.daniel.invent.designEraseMEspamspam_OUTxtra.co.nz> writes:
>Hi Harold,
>
>if the nutral breaking contact fails, then apliance fails with all
>circuitry at 230vac, makes it more dangerous to service.  remember
>that
>amatures *will* fiddle.

Hopefully even amateurs will know enough to turn the breaker *off* before
fiddling.  In that case, the line contact will open too and the circuitry
will be safe.  Using a two-pole breaker makes it much safer with the
breaker off in the more likely event that the line and neutral wires have
been exchanged somewhere on the way into the equipment.

Of course you need to go by the locak country's requirements for anything
that's exported.  For what it's worth, a two-pole switch is used on PC
power supplies sold worldwide.



_____________________________________________________________________
You don't need to buy Internet access to use free Internet e-mail.
Get completely free e-mail from Juno at http://www.juno.com
Or call Juno at (800) 654-JUNO [654-5866]

1998\08\21@121058 by Harold Hallikainen

picon face
       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
12 channel, 20 amp per channel light dimmer run off a three phase Y.  Our
design (which is standard in the US) distributes the incoming three
phases each to four circuit breakers.  These breakers then drive chokes
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.
       As long as the neutral is indeed near ground, this appears safe.
However, this bid request from Jordan is specifying two pole breakers.
I'm thinking we need to replace all the breakers with two pole breakers,
distribute the neutral to each breaker, then have a neutral and hot pair
for each load on the terminal block.  Our main problem seems to be
finding the two pole breakers that will fit where the existing single
pole breakers fit.
       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!
       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.
We can get them, but it VERY unlikely that they will fit the wall outlet
in the country the user is in.  What are the rest of you doing?  I'd sure
like to have a US supplier that I can call up and say "I need a 12VDC,
500mA, 2.1mm, center positive wall wart for Nigeria" and they'd send me
the right thing...

Thanks!

Harold




Harold Hallikainen
RemoveMEharoldspamTakeThisOuThallikainen.com
Hallikainen & Friends, Inc.
See the FCC Rules at http://hallikainen.com/FccRules and comments filed
in LPFM proceeding at http://hallikainen.com/lpfm


_____________________________________________________________________
You don't need to buy Internet access to use free Internet e-mail.
Get completely free e-mail from Juno at http://www.juno.com
Or call Juno at (800) 654-JUNO [654-5866]

1998\08\21@130857 by Peter L. Peres

picon face
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

1998\08\21@135629 by Dwayne Reid

flavicon
face
>        I've got a customer asking us to use a two pole circuit breaker
>to handle single phase loads on a 230VAC three phase Y (or star) system.
>I would expect them to put the load between a line and neutral, with a
>breaker only in the line side of the circuit (at least that's what we do
>here in the US, but this is for Jordan).
>        It APPEARS they want to use a two pole breaker with one pole
>breaking the hot, the other the neutral.  Is this done?  Anyone in
>Jordan?

I'm not in Jordan, but I've seen this often in european equipment, as well
as some DEC AC power distribution boxes..  As far as I know, this is
completely legal.  The neutral wire is longer a neutral after the breaker
and must NOT be the same colour as the neutral.  It is simply regarded as a
line conductor after the breaker.

In general, a neutral conductor can never be opened.  Once a peice of
equipment allows a neutral to be opened, it is no longer a neutral conductor
past that point.

dwayne


Dwayne Reid   <dwaynerEraseMEspam.....planet.eon.net>
Trinity Electronics Systems Ltd    Edmonton, AB, CANADA
(403) 489-3199 voice     (403) 487-6397 fax

1998\08\21@202715 by Russell McMahon

picon face
Interestingly, I believe this is illegal in NZ where only the phase
(live) may be switched (but I may be wrong).

{Original Message removed}

1998\08\22@025628 by Ray Gardiner

flavicon
face
>  Once the appliance has a flexible cord connecting it to an outlet (or
>even a wiring box), there4s a chance that the cord will be damaged and
>rewired, possibly by an unqualified person.  Without the guarantee of
>which wire is which, you must isolate both.  The same applies to circuit
>breakers and it is very reasonable of them to isolate both lines if
>tripped.

A few years back, the following situation occurred at our local college.

A power point was wired with active/neutral reversed at the power point.
Several years passed and no-one ever noticed it.

Until, someone plugged in a IEC power cable with neutral/ground reversed,
this was a pre-assembled cable (moulded connections both ends) that had been
in use (elsewhere) for a number of years.

Put the two together and *BLAM* the path to ground was through his
video monitor. The monitor caught fire, (well, kind of smoked a lot).
Totally destroyed the guy's motherboard.


       A ----+\/----->N>-------------->N>-------> Monitor A
       N ----+/\----->A>------\/------>E>-------> Monitor N
       E ------------>E>------/\------>A>-------> Monitor E

     SBoard         Plug    IEC cable    Computer  Monitor

The danger in this type of fault, is that either can lie dormant for years
and it is not until the two faults are combined that a lethal situation
results.


>  By the way, a little commonsense here suggests the active fuse be
>rated between 70% and 50% of the neutral, so it blows preferentially for
>internal overload while the neutral *only* blows for a ground short.  (I
>say *commonsense*; the standards may say different for all I know!)
>--

I see problems here if active/neutral were reversed then this scheme would
create a potentially lethal hazard. For this reason, I think RCD(*) protection
is a safer solution. AND always check all cables and power points.

This is perhaps a good argument to get rid of ground connections completely
and remove the distinction between active/neutral. If there is no path
to ground then you be a lot safer than our current system.

(*) RCD = Residual Current Detection, what you do is compare the current
in Neutral and Active and if there is an imbalance then the circuit breaker
trips. There is a time/current curve for this tripping action, but it is
in the order of a few mA for a few ms.  IE 30ma imbalance for 50ms would trip.

---------------------------
Ray Gardiner EraseMErayspamhdc.com.au

1998\08\24@103256 by lilel

flavicon
face
Harold Wrote:

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


I would be very surprised if this is the case.

> However, this bid request from Jordan is specifying two pole
> breakers. I'm thinking we need to replace all the breakers with two
> pole breakers,

At least in the US, "Two pole breaker"  Indicates a breaker with two
switches, EACH connected to the HOT side of two different phases, and
the COLD side always connected to Neutral.

We also have many headaches determining power and outlet requirements
for various countries.  There is a company that specializes in
oddball plugs.  They are Panel Components Inc.  1-800-662-2290 or
(515) 673-5000  They have a cool chart in their catalog  and lots of
technical data on universal plugs and international cordsets.


BTW Harold, did you really originate the quote in my signature line?



-- Lawrence Lile

    "The ideal design has zero parts"  -
           (attributed to Harold Hallikainen)

Download AutoCad blocks for electrical drafting at:
http://home1.gte.net/llile/index.htm

1998\08\24@121124 by Harold Hallikainen

picon face
On Mon, 24 Aug 1998 09:30:07 +0000 Lawrence Lile <RemoveMElilelEraseMEspamEraseMEtoastmaster.com>
writes:

>We also have many headaches determining power and outlet requirements
>for various countries.  There is a company that specializes in
>oddball plugs.  They are Panel Components Inc.  1-800-662-2290 or
>(515) 673-5000  They have a cool chart in their catalog  and lots of
>technical data on universal plugs and international cordsets.
>

       Yes, I've got a bookmark set to that page of their website.  The
chard doesn't tell us anything about hots, neutrals, grounding, etc., but
it's certainly a start!  Their chart is derived from a booklet from the
Department of Commerce that I also have buried here somewhere.  I haven't
seen it in a while, so it may be lost.  It had a blue cover (that should
help find it!).
       I also previously mentioned on the list that it'd be great to
find a wall wart supplier that could send me the right thing if I request
a 12VDC, 500mA, 2.1mm coaxial connector, center positive, for use in
Nigeria.  As someone else pointed out, we can ship external universal
input desk top supplies with IEC 320 (I think that's the number)
connectors for power input.  The customer can just buy a local power cord
or put a plug on the US one we send.  These are quite a bit more
expensive than wall warts, though.


>
>BTW Harold, did you really originate the quote in my signature line?
>

       I never heard it from anyone else!  Thanks for including it!  I
came up with that when I taught electronics at Cuesta College, here in
San Luis Obispo, CA.  Students would come to me with these projects that
appeared to have been designed using "brute force engineering" where you
keep throwing parts at it until it works.  I always TRY to approach my
ideal design of zero parts.
       I've heard the story of a guy named Muntz who manufactured TV's
and stereos in the 1950's (Muntz Stereo, etc.).  His TV's were designed
to work in the cities while the more expensive brands worked in the more
rural areas where signals were not as strong.  As a result, he sold lots
of inexpensive TV's.  Anyway, the story goes that he would visit his
engineers working on a new design.  He'd start cutting parts out of the
circuit until it stopped working, then he'd put that one back.  The
process became known as "Muntzing the circuit."



>
>
>-- Lawrence Lile
>
>     "The ideal design has zero parts"  -
>            (attributed to Harold Hallikainen)
>



Harold



Harold Hallikainen
RemoveMEharoldspam_OUTspamKILLspamhallikainen.com
Hallikainen & Friends, Inc.
See the FCC Rules at http://hallikainen.com/FccRules and comments filed
in LPFM proceeding at http://hallikainen.com/lpfm

_____________________________________________________________________
You don't need to buy Internet access to use free Internet e-mail.
Get completely free e-mail from Juno at http://www.juno.com
Or call Juno at (800) 654-JUNO [654-5866]

More... (looser matching)
- Last day of these posts
- In 1998 , 1999 only
- Today
- New search...