Take the 2-minute tour ×
Electrical Engineering Stack Exchange is a question and answer site for electronics and electrical engineering professionals, students, and enthusiasts. It's 100% free, no registration required.

I've been looking around for the schematic symbol to use in a circuit drawing for a FAN. I'm not sure it exists. Do we use a Motor symbol when wanting to show a FAN? And just specify the motor ratings? IE 12V DC?

I've looked @ all the websites listed on Wikipedia (http://en.wikipedia.org/wiki/Electronic_symbols) as references for symbols and many Google searches.

After all, a FAN is just an electro-magnetic motor, isn't it? Does electronics specify at all between motors? (Not by 2 / 3 phase or various speed). But by different type?

I've also found symbols used in other engineering fields that specify a fan in their schematics. Can this be used?

So, essentially the question is, What symbol to use to specify a FAN in an electronic circuit?

Thanks all,

Motor vs FAN symbol

share|improve this question
    
Top one is brushless, next one is brushed. –  jippie Jan 6 at 17:44
1  
You may use a "motor" symbol to show its function, or you may simply use a "coil" symbol to show its electrical behaviour. In schematics, I usually use the latter. –  Laszlo Valko Jan 6 at 17:44
    
Use the motor symbol and name is FAN1, FAN2 etc –  alexan_e Jan 6 at 18:00
1  
Thank you all. Can someone please answer the question so that I can accept it? –  fizzy drink Jan 6 at 18:45

1 Answer 1

up vote 3 down vote accepted

From an electronic device schematic point of view, a fan simplifies thus:

Fan ==> Motor ==> Inductor coil(s)

Of course there are fans that do not use coils at all (piezo fans, coil-less motors), but let us set that aside for a moment.

At the lowest level of abstraction, thus, a purely electrical schematic symbol using one or more inductors could suffice to indicate a motor, such as these symbols for DC motors:

DC motors
(Source)

Another source suggests the stepper motor symbols below: Stepper motors ()


At a higher level of abstraction, the familiar symbol(s) with the letter "M" in a circular enclosure are commonplace, such as the brushless and brushed motor symbols illustrated in the question.

At a more pedantic level, some schematics use the M-circle symbol with a variety of enhancements to specify the various types of motors. This page provides an entire flood of symbols for specific motors.

3-phase series motor 3-phase unidirectional linear induction motor

Note the use of both inductor and M-circle to address both electrical and functional symbolization in the 3-phase series motor above.


Even so, our symbols so far do not indicate the use of the motor for a fan. For fans specifically, there isn't any universally followed symbol AFAIK, but a few variants show up in various documents:

Fan motor (clearly, a fan!)

Fan motor (AC motor -> fan)

The "Other standards" fan symbols shown in the question are not so common in electronic design related schematics, they are used typically for process engineering and electrical wiring.


In summary, for lack of any universal standard, the symbol to be used is best determined by the purpose of the schematic: Is it important to account for inductive behavior, or to illustrate the type of motor, or at the most mundane and abstracted level, is it crucial to convey clearly that "This motor here is a fan"?

share|improve this answer
    
This is spot on - it depends on the intended audience of the drawing, and what they need to know. For what it's worth, on electrical distribution single-line diagrams, motors are nearly always shown as just "M" and the function of the motor is added as an annotation, as in "No. 3 Ventilation Fan". –  Li-aung Yip Jan 7 at 8:19
    
Great answer. That was good and I like the references. Thank you! –  fizzy drink Jan 7 at 13:17

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.