Electrical Drawing Register, Best Practice

There is no real guidance in easy-to-read format as far as I know, but there are standards that might help. The basic standards for the drawings are:

• BS EN 61082-1 General rules for electrotechnology documents and drawings (includes some basic structuring principles)
• BS EN IEC 81346 series for industrial systems and installations (includes structuring principles)
• IEC 60617 (on-line library - as specified in BS 7671) Graphical symbols for diagrams
• BS EN IEC 60445 and BS EN IEC 60757  (terminal identification and colour code abbreviations for interconnection diagrams.)
• BS ISO 14617 series Graphical symbols for diagrams

Dependent on the use of the drawings, other standards may apply:

• BS EN IEC/IEEE 82079-1 if the drawings or diagrams are intended to be used with or for user instructions
• BS 1553 series for piping systems and plant (including P&ID)
• BS 4737-5-2 Intruder alarm systems. Recommendations for symbols for diagrams.
• BS 1635 (although this has not been updated since 1990 and is out of date with respect to current technology and practices) Recommendations for graphic symbols and abbreviations for fire protection drawings
  
  

I look forward to the answers on this one.

In the construction sector I've not seen a specific standard dictating comprehensively which drawings are or are not supplied. Assorted standards do require particular drawings are provided specify pieces of information that need to be provided (e.g. BS7671), which is often easiest to communicate as a drawing, and some, generally industry-specific, standard do state XYZ drawing is required. But these are minimum criteria; I'm not aware of one providing a comprehensive list at least for the fields I work in and I'm not sure how it would work.

In practice it's generally left to a combination of contract (where a client has specified a particular set of documents in advance) and whatever is needed to communicate the design from the designer to the construction team... In practice as you say many firms end up with a standard suite to suit the type of project they work on and clients they work for, which makes life easier as everyone knows what to look for and where, and eccentricities are often more apparent, and this often evolves with time and experience. Industry expectations vary also (which can be fun when a client or contractor moves into a new sector).

For what it's worth, I am always wary of repeated information, because in my experience when it is there is a very real chance that documents go out of sync and its normally the wrong version that gets used. But the temptation to avoid this with a single monolithic drawing with everything in it should be resisted as it can be difficult to get the information out, and different people will be using the information for different tasks. Balance is required: Every piece of information in every drawing should be there for a reason lest it crowd out the important bits or even become a liability later; nothing should be unsaid or assumed that as a designer you may have an opinion on later, unless it is stated elsewhere in documents the relevant people have been referred to.

With an experienced CAD Tech this can often be managed (for example, separating the monolithic model from multiple layout sheets, (X-)referencing common content*, or using tools to automatically generate schedules), which often also saves a good deal of repeated work.

*Be mindful that vanilla AutoCAD and AutoCAD Electrical both use the phrase XREF but mean different things. Both are worth knowing about.

Have downloaded a copy of these standards to have a look through, thank you so much.