Lowercase letters on drawings 2

[danielthb]

After 33 years of preparing and reviewing engineering products for the government, I'm working in the "real world" now. I'm in a "discussion" with our drafters who insist that in the term "440VAC/60Hz/3PH" not only is the little bitty illegible "z" OK, but it is "required." Their arguement is that Y14.38 shows "Hz" for both drawings and text. I said yeah but in 270+ pages of abbreviations it's the only lowercase letter shown for use on drawings except for "rddr" which is pretty obviously a typo. One lowercase letter in one abbreviation of all the abbreviations that the standards committees could dream up. I think that Y14.38's use of "Hz" on drawings is a typo, too.

Do you allow lowercase letters on your engineering drawings? Does anyone know of an addendum to Y14.38 that addresses this particular matter?

Dan Blackwell

 

[doct9960]

Dan,

I don't think it's a typo. The correct abbreviation for hertz has always been Hz. Hertz is an SI unit. Systeme International prefers lower case on spelled out and abbreviated units like gram (g), metre (m), etc. You will probably notice capital letters on some units with prefix (e.g. MHz or GHz) or in units named after people like...
hertz (Hz) after Heinrich Hertz
newton (N) after Isaac Newton
pascal (Pa) after Blaise Pascal; etc

 

[danielthb]

Not talking about SI symbols in the 260 standard, just abbreviations. And not in manuals, books, papers, etc., just on drawings.

In 33 years, I've never seen it on an engineering drawing. I've seen HZ and I've seen HERTZ, but never Hz. Y14.2 says lettering on drawings will always be uppercase unless otherwise required. I take that to mean something like a pin in a connector physically labelled with a lowercase letter that you're depicting on a drawing. And even that has other ways it can be designated without actually using a lowercase letter on the drawing.

Look down the column of abbreviations for use on drawings in 14.38. There's one lowercase letter (ignoring rddr) in almost 280 two-column pages of uppercase abbreviations. That one little "z" in one abbreviation is the singular required lowercase letter in ANSI's entire committee-determined-and-approved list. I just don't see 20 or 30 people, who have blessed thousands upon thousands of all caps abbreviations reaching a concensus that there is any one abbreviation so universally used and so confusing if written another way that it should be the sole exception to an otherwise perfectly consistently applied rule--all caps on drawings.

DB

 

[doct9960]

In 33 years, I've never seen it on an engineering drawing. I've seen HZ and I've seen HERTZ, but never Hz. Y14.2 says lettering on drawings will always be uppercase unless otherwise required.

33 years does not mean that you know and have seen everything. ANSI/ASME did not "dream up" Hz. It is the "unless otherwise required" they were referring to. As I was saying before, hertz is an SI unit. Before hertz, the Americans (ANSI/ASME) were using cycles per second as one of the units of frequency. I believe they adopted hertz in the 1970's.

In my 13 years of EPCM service for the oil, gas & chemical industries, RARELY did I see the abbreviation "HZ", with a capital zed, to refer to hertz. When I check our own drawings, I always tell our drafters to use the correct abbreviation "Hz". When I check external drawings (e.g. vendor drawings) and see the term "HZ", I just let it go. I know and the vendor knows that it means hertz anyway. There are far too many important stuff to worry about than to nitpick on spelling or capitalization errors.

 

[JLSeagull]

Dan,
Most of us are changing our practices as recommended by many documents. I am a bit nuts regarding abreviations, especially for units. My Engineering in Training Handbook for the Fundamentals of Engineering exam initiated my conversion. My comments apply to keyboard drafting. Further, early keyboards for ASCII symbols were limited to only capital letters - such as teletype. This is no longer the case.

Engineering units for proper names normally begin with a capital letter. This applies to Volts, Amps, Hertz, Fahrenheit, Siemens, etc. The abreviation for multipliers up to kilo use lower case. The larger multipliers beginning with mega use a capital letter. This differentiates m milli from M mega. The unit symbols may be one or more letters. Examples Hz for hertz and mm for millimeters as well as I for current.

Refer to standards such as ANSI, ASME SI-1, ASTM SI 10, NIST 330, NIST 811, ISO, IEEE SI 10, IEEE Std 260.1 etc.

 

[danielthb]

9960,

I didn't mean to come across as a know-it-all. My apologies. My use of the term "dream up" was meant simply to denote thay had specifically included "Hz" in their document in stark contrast to all other abbreviations.

All,

Y14.2 still says all caps on drawings unless required otherwise. Again, I'm talking strictly about presention of information on an engineering drawing. I felt and still feel that HZ is appropriate for use on drawings.

A good week to all.

Dan

 

[fcsuper]

Dan,

In addition to other replies, I'll point out that if one only used caps when writing in unit abbreviations, this can create confusion since some capital letters mean something different than their lowercase counterparts. For example, milliwatts is mW and megawatts is MW. Wikipedia Chart



Matt
CAD Engineer/ECN Analyst
Silicon Valley, CA
sw.fcsuper.com
Co-moderator of Solidworks Yahoo! Group

 

[JLSeagull]

4.3 recommends upper case on drawings unless lower case letters are required then refers to figures 14 and 15. Note that these are hand lettering examples. Figure 14 for inclined letters would apply to formulas. Figure 15 for vertical letters would apply to the engineering units.

Drafting was an art or craft. My performance reflected my lack of such "craftpersonship". If you look at most drawings you may still find all capital letters. However, I would not expect this to be the case upon the next issue of Y14.2. I see no mention of cases or capitalization in ASHRAE standard 134-2005. Nearly everything is upper case in the symbol descriptions -- except kPa for kilo pascals.

I also notice that the descriptions use PSIG instead of psig. Slap my hand if I type PSIG instead of psig. I am confused regarding volts alternating and direct current. Which is correct, Vac and Vdc or VAC and VDC?

 

[fcsuper]

I've never seen Vac nor Vdc under any system of detailing. I've only ever seen VAC and VDC, regardless to where it appears. Have you seen Vac used somewhere?

Matt
CAD Engineer/ECN Analyst
Silicon Valley, CA
sw.fcsuper.com
Co-moderator of Solidworks Yahoo! Group

 

[JLSeagull]

I have see lower case used for alternating and direct current in the abbreviation. I started using it and find that it just seems wrong.

 

[Ashereng]

I have seen CYCLES used instead of Hz. Don't know if that helps.

Yes, lower cases are used, such as kW, kVA and etc.

Yes, most of the drawing is in upper case.

In the end, does it really make a big difference?


"Do not worry about your problems with mathematics, I assure you mine are far greater."
Albert Einstein
Have you read FAQ731-376 to make the best use of Eng-Tips Forums?

 

[fel3]

I don't have a problem using lower case on engineering drawings, though we don't do it much. In fact, I insist on "No." for number instead of "NO" because I have seen cases where it DOES matter. I actually wish we could do away with the "all uppercase, all the time" method of producing drawings. The standard mix of UC/LC is easier to read and less prone to ambiguities.

Fred

 

[fcsuper]

I'm personally in favor of all caps (except for international abbreviations, as noted above). In the context of a drawing, it is much easier to read all caps, at least for me. GRANTED, THERE ARE MANY PLACES WHERE ALL CAPS CAN BE CONFUSING, SUCH AS MESSAGE FORUMS, where it is considered yelling. hehehe

Matt
CAD Engineer/ECN Analyst
Silicon Valley, CA
sw.fcsuper.com
Co-moderator of Solidworks Yahoo! Group

 

[namdac]

According to ANSI not just Y14.XXXXXX Upper and Lower case are used in ALL drawings. Abbreviations are set specifically as follows: k - is metric abbreviation for kilo....etc. Hertz being a measure of fequency is abbreviated as Hz. There are a couple of web sites that talk about abbreviations and standards. A good place to look is FAA-STD-002e This talks about ALL drawing and text requirements the FAA requires on ALL drawings. These abbreviations have already been established why fix it if it is not broken?
Regards,
Namdac
P.S. One piece of friendly advice quit trying to read between the lines and just do it.