Power & Lighting plan drawing style preference

[James M. Clarke]

I have read many of this forum's members various opinions about the appropriate way to show circuiting on a power plan or lighting plan contract drawing. My question is this, 90% of the time the existing projects I review show the typical receptacle to receptacle loops, the homeruns with the panel and circuit number and the tic marks denoting the ground, neutral and hot wires in the run. The other 10% simply show the outlets on the floor plan and put the panel number and circuit number in the middle of the room or rooms the circuit will serve and assume the EC will wire it as best as possible (and probably will).

So, now I have a job to do for the air force and the 65% submittal is requesting circuiting on the power plan. In your opinion, does this mean the drawing can be done either of the ways listed above or does it mean the old loop, homerun and tic mark style.

Secondly, the project my firm is inheriting already has the plan drawn out like the 10% mentioned above but it distributes the outlets in various rooms in some cases erratically (I suppose this was done to eliminate breakers tripping when a meeting is held in one of the conference rooms with lots of equipment). It was difficult to trace out because it lacked the typical loops from outlet to outlet and I was concerned the the EC might miss some of the outlets that were far from the majority cluster or might take the easy way out and wire all the outlets in a medium sized room to one circuit and not alternate three circuits as shown.

Is there a right or wrong way to do this type of diagram or is it is simply a matter of personal preference. Please voice your opinion either way. Thanks

 

[nakulak]

imo wiring should meet customer's needs. if they need 3 ckts in a room, then that's how it should be wired. (in my short life I have noticed that regardless of what is spec'd, it would be rare if anyone checked to see that it was wired this way though)

 

[Smart $]

FWIW, the 10%-type is, in my mind and not necessarily factual, more like 0%. :grin:

 

[pbeasley]

FWIW, the 10%-type is, in my mind and not necessarily factual, more like 0%. :grin:

I would agree... maybe on residential, not any of the commercial jobs I've been around, and I find it hard to believe that would meet the requirements of a government contract.

 

[ron]

I have not shown arcs interconnecting devices for a very very long time.
Circuit identification on the power plan is numbers and panel identification on the devices with associated panel schedules.
The arcs are a pain in the rear and do not improve installation results.

 

[infinity]

I have not shown arcs interconnecting devices for a very very long time.
Circuit identification on the power plan is numbers and panel identification on the devices with associated panel schedules.
The arcs are a pain in the rear and do not improve installation results.

Thank you and every other engineer like Ron who makes drawing for commercial projects this way.

Nothing messes up an electrical drawing faster than those arcs with little hash marks all over the place. For a simple residential job maybe, but for a commercial job where many different panels are involved, the panel and circuit designation adjacent to the device, followed by a set of specific notes is sufficient. The likelihood that someone will actually follow those arcs and wire the job that way is nil.

 

[steve66]

I use the arc's most of the time, but I do switch to just labeling a circuit number on a receptacle if I think the arc's are getting too messy.

But I consider the arc's to be schematic: I don't expect electricians to run the homerun from the farthest receptacle just because that's the receptacle I put the arrow on. (I had one electrician who thought he had to use a separate conduit for every home run shown.)

With the arcs, it is much faster to see exactly how many receptacles are on one circuit, and exactly which rooms the circuit goes to. So I think it does have an advantage.

 

[Ragin Cajun]

I have not shown arcs interconnecting devices for a very very long time.
Circuit identification on the power plan is numbers and panel identification on the devices with associated panel schedules.
The arcs are a pain in the rear and do not improve installation results.

You and me both. Haven't used those dumb loops for over 25 years and have no desire to go back. Clutters up the drawing and nobody ever wires them that way.

RC

 

[bbaumer]

It has been a number of years (about 12) since I worked on an air force project but at that time you had to draw the loops. I remember this clearly. It was a job for Wright-Patterson AFB in Dayton, OH.

Why?

Because the company I worked for at the time did not use loops. Just the ckt numbers. I made it through all the reviews up to the 100% plan-in-hand review with it drawn per our standard, no loops.

Took the final drawings to the 100% meeting. An EE from Wright-Pat that I had not seen before was in attendance. The first thing out of his mouth was "you did not draw this per our standard". I said I did not know they had a standard. He left and returned with a copy. This was on a Thursday as I recall. Drawings were due Monday to the AFB. The EE stated we must comply with the standard. I started to argue that since we were not given the standard etc. My boss cut me off mid-sentence and said "Brent, if that's what the Air Force wants, that is what they will get."

A cad operator and I worked all weekend to re-draw the whole job.

I suggest you see if they have a standard and follow it.

 

[charlie b]

Put me down for the "circuit numbers and home runs" faction. I think the "spaghetti," as we like to call the arcs and tick marks, is

(1) A waste of engineer and drafter time, in that it adds no engineering value to the document,

(2) An invitation for errors to creep in and for subsequent issuance of change orders, and

(3) Unlikely to be followed literally by the installer, who knows better than I how to run conduit and wire anyway.

 

[ptrip]

I use the arc's most of the time, but I do switch to just labeling a circuit number on a receptacle if I think the arc's are getting too messy.

But I consider the arc's to be schematic: I don't expect electricians to run the homerun from the farthest receptacle just because that's the receptacle I put the arrow on. (I had one electrician who thought he had to use a separate conduit for every home run shown.)

With the arcs, it is much faster to see exactly how many receptacles are on one circuit, and exactly which rooms the circuit goes to. So I think it does have an advantage.

I'm 100% with you Steve. I do the arcs. I can see at a glance where my circuit is. If I have to re-organize a panel I only have to change one designation on the floorplan. It also helps when I'm checking my circuit load before it goes out final...I would surely miss devices at that point. And yes, it is intended to be schematic in nature.

I do not show the tics or hashmarks. Number of wires, if needed, is in a separate note for the equipment.

I do take the care to make the drawings neat and orderly.

If a lighting plan gets too confusing because of alternating cicruiting (California reqmt for example) I will use a letter designation on the fixture symbol with a note for the room.

 

[bsh]

I agree with Charlie and others who think the loops, tick marks, etc. are useless. Unfortunately, some clients want and expect to see them. Better to find out early in the project the requirements for such things to avoid weekends in the office

 

[steve66]

If I have to re-organize a panel I only have to change one designation on the floorplan.

I hadn't really thought of that before, but you are right, that's another real advantage to using the loops. Circuits always get added after the initial layout, and I also usually try to renumber circuits right before a project goes out so there is some basic order that's followed.

 

[doubleE]

Can anyone show any drawing examples of these styles?

 

[doubleE]

Could anyone provide an example of the different plan drawing styles you're talking about?


Shoot, I'm sorry for the double post. IE was acting goofy and I didn't think the first one took.

 

[Volta]

I like the arcs, arrows for home runs. No hash marks needed. If it's too messy the scale is probably too small.

It is not supposed to represent the actual wiring order, just circuiting and switching.

 

[jeremysterling]

Are as-builts expected to have the arcs as well? I did a 3 story shell from the 10% drawing and when I was asked to mark it up, I said that it was installed just like the drawing... what could I mark?

 

[LarryFine]

The EE stated we must comply with the standard.

I would have said "What you mean "we," paleface?!"

 

[bbaumer]

Can anyone show any drawing examples of these styles?

Here's the idea.

The no-loop method is much faster to draw in the first place so I'm not buying the easier to change later arguement. Yes, it may be but unless you have a ton of changes you will spend way more time drawing it up front than you would making changes.

 

[PCN]

I use both methods depending how congested the area is. I often use it for switching when there is a 3way or 4way involved.

Also when I have say 20 rows of fluorescent fixtures 150' long with a-b lighting I think it looks cleaner with a line or arc between fixtures vs. circuit# & panel name at every single fixture. Usually the emergency lights just get ckt# and panel due to spacing.

If done neatly I think it looks cleaner. We usually have 15 or 20 panels through out our buildings so we can't just use a number, it has to have a panel designation as well.In some areas that ends up being alot of text and can look chaotic.

I like the more schemetic style line better than an arc. But both have there place.

Just my 2 cents worth.