Standard Electrical Symbols

[ramyadevi89]

Hi,

Hope all are having a great work day!
I found some NEMA Standard Electrical symbols for one line diagram. Are we following NEMA standard ?
if not where can I find standard Electrical symbols used for one line diagrams?

Thanks in advance

 

[steve66]

Most people in the US probably use the NEMA standards. Some people (myself included) probably mix in other random symbols for devices that NEMA doesn't include.

The IEC standards are more likely to be followed in some other countries. Here is a comparison between some of the symbols in NEMA and IEC:

http://www.offshore-industries.com.sg/images/comparison_of_iec_and_nema_schematic_diagrams.pdf

 

[petersonra]

did you notice on the first page of the pdf where it says capacitor instead of circuit breaker?

 

[K8MHZ]

did you notice on the first page of the pdf where it says capacitor instead of circuit breaker?

That's funny!

 

[Smart $]

https://www.google.com/url?sa=t&rct...NrJaGUxYxqWmUMkVQ&sig2=TqS5i5JavOMIYIQOyfprOw

 

[K8MHZ]

https://www.google.com/url?sa=t&rct...NrJaGUxYxqWmUMkVQ&sig2=TqS5i5JavOMIYIQOyfprOw

From page 14.

Duples receptacle ceiling mounted 20A 125V.

:roll:

 

[Smart $]

From page 14.



:roll:

Is there a point besides misspelling duplex?

 

[ramyadevi89]

Got it:thumbsup::thumbsup:..Thank you all..

 

[Jraef]

So just to be more correct, NEMA has nothing to do with wiring diagram or one-line diagram symbol standards. In fact, NEMA is not really an official standards organization, it's a manufacturer's group. The people who call them "NEMA symbols" are usually Europeans who don't know about how we operate. That document says Eaton on it, but that's just because Eaton bought Klockner Moeller a few years ago, and that publication came from KM, a German company.

Official one-line diagram symbol standards for North America are maintained by ANSI, they can be found in ANSI Y32.2-1975, and the numbering of devices on a one-line diagram comes from ANSI C37.2-1996

The symbols we commonly use for wiring diagrams (different from one-lines) are what used to be called the "JIC" standard (Joint Industrial Council), but although the JIC was absorbed by NFPA-79 a long time ago, they are still referred to as JIC symbols.

 

[K8MHZ]

Is there a point besides misspelling duplex?

If you mean 'is there a point besides bringing attention to the word duplex being misspelled', that's pretty much it. I guess the 'capacitor' typo was a hard act to follow.

It's funny how typos that are noticed in minutes by forum readers slip by the publisher's proofreaders. I got a letter from the NFPA once about a membership or something and they spelled electrician wrong on it.

 

[steve66]

So just to be more correct, NEMA has nothing to do with wiring diagram or one-line diagram symbol standards. In fact, NEMA is not really an official standards organization, it's a manufacturer's group. The people who call them "NEMA symbols" are usually Europeans who don't know about how we operate. That document says Eaton on it, but that's just because Eaton bought Klockner Moeller a few years ago, and that publication came from KM, a German company.

Official one-line diagram symbol standards for North America are maintained by ANSI, they can be found in ANSI Y32.2-1975, and the numbering of devices on a one-line diagram comes from ANSI C37.2-1996

The symbols we commonly use for wiring diagrams (different from one-lines) are what used to be called the "JIC" standard (Joint Industrial Council), but although the JIC was absorbed by NFPA-79 a long time ago, they are still referred to as JIC symbols.

They may not be an official standards organization, but they do publish a standard with one-line symbols:


http://web.fscj.edu/Mark.Bowman/handouts/NEMA electrical and schematic symbols standards .pdf

 

[mgookin]

NFPA has standardized symbols which we use for life safety plans.
It's NFPA 170.

 

[kingpb]

I think the general rule of thumb is that you can use whatever symbol you would like, as long as you provide a legend sheet.

With that said it is best to use what people are most familiar with; in US that would be ANSI symbols. Although, ANSI recognizes IEC symbols as being acceptable. I personally like the IEC power transformer, voltage transformer, and current transformer symbols better.

 

[jumper]

I think the general rule of thumb is that you can use whatever symbol you would like, as long as you provide a legend sheet.

:happyyes:

 

[qcroanoke]

It's funny how typos that are noticed in minutes by forum readers slip by the publisher's proofreaders. I got a letter from the NFPA once about a membership or something and they spelled electrician wrong on it.

I am a real stickler for correct spelling and using the correct word (there, their, they're) and I think the designers whose drawings I check appreciate me being that way.
I'm not a municipal employee I work for a private firm.