Can anyone help me out by giving me an example
of their electrical schematic. I would like to
review different types of schematics to design the
best schematic format for our company. It seems like a lot of people do their own thing. Is there ISA, ISO, or IEEE standard title blocks?
Email me whatever you are allowed to share!!
Thanks a lot for your help!

Mike
(mhubbell(AT)thomaseng.com)

 

I suggest the following steps

1) talk to your end users and find out what they like. By this I mean the end user of your print, (not his boss) ie the maintenance guy that has to maintain the equipement and the panel builder that assembles the system. Keep them in mind. This is perhaps the number one reason many people tag wires and devices to match the print line number on which the device appears. It makes it easy to find later.

2) Get a good electrical cad system. My favorite is ViaWD from Via Development. They offer a lite package, but the full WD version is far better and worth the money. Ive used a couple of others including promis-e and I like ViaWD the best. A good cad system will automate most of the popular formats.
www.viadevelopment.com.

 

Good point to talk to the end user. The good people that are to live with the designs are most important.
I am a strong advocate of origination-destination labeling for all wire, cable, and conduit.
Place as much information as possible on the drawings without confusion. Also never hesitate to heavily note on the drawings. Equipment, and devices within the documents and as well interface with,and interlock with the control scheme should be discussed.
The narrative can be, and 9 times out of 10 is valuable to understanding the mechanical aspect of what the controls are executing.
A simple example would be a pump with control valve with positon feedback. The feedback incoporates both discrete and analogue position, and the state for start-up of the system through the run sequence is critical.Interlocks for the same to automate and as well interlocks which are condtions for the valve and pump to perform.
Another is the sequencing involved for fuel guns for boilers in the power generation business.
The NFPA 79 Electrical Standard for Industrial Machinery(2002-3), whatever year you can acquire, is a fine document.
Most manufacturers have wiring diagram bulletins which are great reference for the design basis. You may be lucky enough to get a hard copy from one of the reps. Most of the manufacturers(AB, Square D, Cutler-Hamer, Siemens, ABB) have their formats. Great reference.
If you are fortunate to get your hands on a sound Electrical CAD Package, it will be a windfall. Life is easier.
Good Luck!
Paul Dackermann

 

Forgot to mention earlier:
Process Flow Diagrams (PFD) and Piping and Instrument Diagrams are available through the ISA. Some documentation numbers to check are ISA s5.1 "Instrument Symbols and Identification", ISA s5.4"Instrument Loop Diagrams", and ISA s51.1"Standard Process Instrumentation Terminology".

As a side bar. One of the best activities in this design process is coming up with documents which have a useful life.

Create the document so that it presents the necessary and relevent data and information lending ease to the user as the end result.

Best Regards,
Paul

 

Check out "Control System Documentation" by Raymond Mulley, available from the ISA.

Bruce

 

try and get a copy of the free publication by klockner moeller

"Wiring Manual automation and power distribution"
www.moeller.net

it has a very good section on symbols and circuits

good luck
jeff

 

Mike,

My view is that drawings are only used twice, once for manufacture and commissioning and then for fault finding. As manufacturers make the
majority of drawings, they tend to be laid out to aid assembly. I worked for many years in TV and Video servicing, which was an excellent
grounding in electronics; The drawings we used were specifically for servicing and fault finding, giving typical voltages, currents and
waveforms. Most importantly though the drawings are laid out logically, by function, so for example, the sound circuits were grouped together, which means quicker isolation of the fault and swifter repair. I try, in my own companies' drawings, to incorporate some of these
ideas. Your drawing policy should be a part of your overall design and manufacture system, which takes into account cable numbering and panel
layout. There are many standards out there for symbols and layout, but your policy should primarily cover your companies’ equipment and needs. I’ve posted some of my drawings at

http://www.germainesystems.co.uk/drawings.pdf

I hope they are of some interest to you.

Marc Sinclair

 

Please have a look at the EPLAN website. EPLAN is an electrical package that can draw in IEC, DIN or JIC. If one customer needs a machine in EN60617 then another needs the same in JIC then just change a standards button and the library.

Have a look at a sample on http://www.eplan.co.uk/eplan_sample/index.htm

The electrical schematics have been designed in EPLAN and saved as a PDF.

Regards
John