Need IEC symbol orientation advice

[Anonymous]

If anyone who is familiar with IEC symbology has a minute or two, I could
use some advice. The attached drawing has some sample "horizontal" version
IEC symbols. My question is this... the angled wiper orientation for N.O. vs
N.C. ... should the N.O. always be on one side of the line (above or below)
and the N.C. version always on the opposite side or doesn't it matter?

[Anonymous]

Hi Nate, I've just looked in a copy of the iec standard and it would appear the symbols marked with an * is the "preferred symbol" orientation. Yes it is important the NC/NO symbols are opposite. If not, it could be interpreted that a NC contact is being held in the open position in its "normal" condition eg, a roller switch operated by a mechanical flag. Hope this helps.

[Anonymous]

Many thanks for taking the time to look it over! We have one vote for the
"*" orientation. Anyone else?

wrote in message news:5085388@discussion.autodesk.com...
Hi Nate, I've just looked in a copy of the iec standard and it would appear
the symbols marked with an * is the "preferred symbol" orientation. Yes it
is important the NC/NO symbols are opposite. If not, it could be interpreted
that a NC contact is being held in the open position in its "normal"
condition eg, a roller switch operated by a mechanical flag. Hope this
helps.

[Anonymous]

Maybe this is the easiest way to determin wich one is ok.
Draw a vertical one with 1NO and 1NC pushbutton in it and then rotate it (base point is bottom) couterclockwise.
This is the same as the *, but the control symbol (eg pushbutton. etc....) is on the good side of the contact.
So I also would say the * but with the control symbol on the other side. Always in the same direction as the angled wiper moves.
See also dwg attached

[Anonymous]

It appears the symbols in the dwg need to be horizontally flipped.
i.e. for NC the wiper should be above the line, for NO the wiper should be below the line.

In theory the vertical symbols should be rotated 90 deg anti-clockwise.

However in ACADE 2006 the symbols are not only being rotated, they are also flipped making them incorrect.

Having this very problem now... how can I "unflip" the symbols?

[dougmcalexander]

I agree with you Peter. Excellent illustration.

[dougmcalexander]

Nate the truth is that most IEC drawings don't contain horizontal symbols. In the off chance that a user needs to insert a switch or relay contact in a horizontal orientation it would seem to me that it would make most sense to locate the actuator portion of the symbol on the top side with INST, LOC, and TAG above the actuator, thus meaning that the symbol was rotated clockwise. Then the description attributes and XREF could be located beneath the symbol. Default locations are only starting points anyway since we can move the attributes around. Competitive programs don't even have default attributes other than INST, LOC, and TAG anyway. They locate these next to the actuator portion of the symbol, left of vertical or on top for horizontal. Any other attributes must be inserted manually and located as desired on insert. So deciding on a standard horizontal appearance for IEC symbols is more of a judgement call to me since the horizontal symbols are most likely to come into play when performing a library swap from JIC to IEC on a ladder diagram. The same wouldbe true in reverse if performing a library swap from IEC to JIC, thus requiring vertically oriented JIC symbols to replace the standard vertically oriented IEC symbols. So I think what is most important here is that the IEC vertical and JIC vertical symbols have similar attribute locations and the IEC horizontal and JIC horizontal symbols have similar attribute locations, so the library swap feature can function without lots of cleanup being necessary. With all that being said I think the geometric portion of the IEC and JIC symbols should also be position similarly.

Now to through a wrench in the works, the Australians typically use a IEC orientation like IEC. When I was there I saw their version of IEC60617 and it only showed vertically oriented symbols. But the Australians told me that when they need horizontallay oriented symbols they usually rotate counter-clockwise. I actually saw a few drawings that were done that way from one of the companies down under. They seldom use horizontal though, just like with IEC. This particular case was an Australian company using a ladder diagram format.

I know this is a lot to bite off and get right, but AcadE just about need to cover all bases, so Australia can use the symbols as needed and so can Europe and the U.S. But to me the most important consideration is the library swap, which most competitive programs cannot even perform at all or do it very poorly. AutoCAD Electrical has such a powerful ability with its library swap and I know customers who use this feature extensively. They would be better served if the horizontal and vertical orientations from library to library are seemlessly interchangeable.

[Anonymous]

I'm an Aussie electrician by trade, and use ACADE
on a daily basis. However the Australian Standards seem to change about every
decade or so. When I did my training in the mid to late 80's the push was to use
a vertical ladder with horizontal symbols. This was to allow for easier transfer
to PLC programming if required. In the area of the industry where I currently
work, about 50% of the dwgs are specified with a vertical ladder. These
specifications are usually by the older engineers/electricians who prefer the
vertical ladder (Must admit I prefer it as well).

As for symbol orientation, I was taught and prefer
the incoming wire to go to the common terminal unless it's a changeover contact
requiring the incoming wires to go to the contacts with a common output. The
symbols I was taught to use also had the NO contact bar on the top with the NC
contact bar on the bottom. This meant that all the contact bars moved in the
same direction when operating which cuts down on confusion. As for rotating
symbols CCW against CW, CCW puts the symbol in the reverse position to what I
and a lot of electricians where taught.

The Australian Standards are extremely hard to read
and are usually written in legal and engineering jargon. some of the symbol
lists are also very confusing.

Regards Brad

style="PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: 0px">

<dougmcalexander> wrote in message
href="news:6138199@discussion.autodesk.com">news:6138199@discussion.autodesk.com...

Nate
the truth is that most IEC drawings don't contain horizontal symbols. In the
off chance that a user needs to insert a switch or relay contact in a
horizontal orientation it would seem to me that it would make most sense to
locate the actuator portion of the symbol on the top side with INST, LOC, and
TAG above the actuator, thus meaning that the symbol was rotated clockwise.
Then the description attributes and XREF could be located beneath the symbol.
Default locations are only starting points anyway since we can move the
attributes around. Competitive programs don't even have default attributes
other than INST, LOC, and TAG anyway. They locate these next to the actuator
portion of the symbol, left of vertical or on top for horizontal. Any other
attributes must be inserted manually and located as desired on insert. So
deciding on a standard horizontal appearance for IEC symbols is more of a
judgement call to me since the horizontal symbols are most likely to come into
play when performing a library swap from JIC to IEC on a ladder diagram. The
same wouldbe true in reverse if performing a library swap from IEC to JIC,
thus requiring vertically oriented JIC symbols to replace the standard
vertically oriented IEC symbols. So I think what is most important here is
that the IEC vertical and JIC vertical symbols have similar attribute
locations and the IEC horizontal and JIC horizontal symbols have similar
attribute locations, so the library swap feature can function without lots of
cleanup being necessary. With all that being said I think the geometric
portion of the IEC and JIC symbols should also be position similarly. Now to
through a wrench in the works, the Australians typically use a IEC orientation
like IEC. When I was there I saw their version of IEC60617 and it only showed
vertically oriented symbols. But the Australians told me that when they need
horizontallay oriented symbols they usually rotate counter-clockwise. I
actually saw a few drawings that were done that way from one of the companies
down under. They seldom use horizontal though, just like with IEC. This
particular case was an Australian company using a ladder diagram format. I
know this is a lot to bite off and get right, but AcadE just about need to
cover all bases, so Australia can use the symbols as needed and so can Europe
and the U.S. But to me the most important consideration is the library swap,
which most competitive programs cannot even perform at all or do it very
poorly. AutoCAD Electrical has such a powerful ability with its library swap
and I know customers who use this feature extensively. They would be better
served if the horizontal and vertical orientations from library to library are
seemlessly interchangeable.

[dougmcalexander]

Good input Brad. I saw drawings with vertical ladder rails (like U.S.) as well as horizontal ladder rails (like IEC) when I was in Ausralia last year. I was most intrigued by the wire colors. Your system was originally based on the British standard with yellow for L2. When I was there last year I saw White for L2 so the three phases are Red (L1), White (L2), and Blue (L3). You guys chose nice colors and Americans should most appreciate it (Ha! Ha!). Actually the colors have a better contrast than the new colors in IEC of Brown (L1), Black (L2), and Gray (L3). It is much easier to differentiate the colors in your panels since the colors are in such stark conrast.

The Australian symbol standard I saw was a recent one that the customer had at their office and it only showed vertically oriented symbols, the same way IEC60617 shows them. The actuator portion of the vertical symbol was on the left side of the symbol, with NO wiper on the left and NC wiper on the right. AcadE has this correct in their vertical symbols and their vertical orientation meets both IEC and AS standards. So the horizontal is the issue. However the customer told me they would rotate the vertically oriented symbol counter-clockwise to achive the appearance that most Aussies prefer.

I suspect that Autodesk has received conflicting information from customers as to the correct default orietation for IEC and AS symbols and that is why Nate wants to get to the bottom of it. Of course AcadE features a symbol reverse/flip tool so you can orient as desired, no matter what the horizontal or vertical default looks like. But I know it is much more efficient if the symbols insert the way you prefer without further modification. I always prefer to orient my symbols in such a way that the live side of the contact is the wiper side. To rotate the symbols CCW often causes the wiper side of the symbol to be the "non-live" or switched side of the symbol. Functionally of course it is not a problem except for Form-C or Changeover contacts. I just think that if I had to do a symbol swap to change a single N.O contact to a Form-C or Changeover contact I would want the wiper to stay on the same side as it was before it was swapped. The AcadE Form-C contacts are designed perfectly to be able to perform a symbol swap and replace a single N.O. or N.C. when design changes are necessary.

My point to Autodesk is that many companies today are designing for a global economy and thus the library swap tool is a huge time saver when you must switch to symbols from a different library. I has been my experience that most Europeans understand vertical ladder rails and will accept ANSI/JIC drawings as long as the symbols match IEC60617. This of course creates the greatest need for the horizontal version of the symbols, because the Europeans would not likely design with vertical ladder rails unless they are meeting a U.S. customer's requirements. So the most likely use of the horizontally oriented IEC symbols is for a libray swap. If the symbols from all of the AcadE libraries have the same orientation, the library swap is not hindered. Of course when swapping IEC or AS to JIC you need to click the appropriate conversion button so the scale is correct and vice versa for JIC to IEC or AS. AutoCAD Electrical has proven to be the most powerful program available for those of us (myself included) who must design for multiple markets, because of its library swap and language conversion utilities. That is why I think the best solution for Autodesk is to keep similarity between all libraries as to the orientation of the graphical portion of the symbols. Edited by: dougmcalexander on Mar 9, 2009 5:43 PM