Good Engineering Practice in Drawings?

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Ragin Cajun

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Upstate S.C.
I have been requested to provide a second engineering opinion on an engineer's stamped drawings. My client's electrician had many "concerns" with the drawings. I found numerous" issues" with the drawings and in reviewing them for my client, I have tried to be "low key".

Aside from numerous other issues, I have several questions for the group.

1. When circuiting lights, receptacles, and other electrical loads, do you place the circuit ID beside each device on the drawings? I think this is good engineering practice. Otherwise the electrician must hand mark-up the paper drawings to properly circuit the loads. This particular set of drawings did not do that.

2. I have always put light and receptacles on separate circuits. I don't want the occupant in the dark when the device connected to the receptacle trips the breaker. Again, this particular set of drawing put both on the same circuit.

3. I have always left either spare breakers or spare spaces in any panel board I layout. This set of drawings had a 54 circuit panel board with ONE spare! Come on man, that is poor engineering design! I thought this was in the code but couldn't fine it.

4. On panel board schedules, I always put individual load data for each circuit and sum each phase up and the overall total. How else can you know that they are reasonably balanced and know the total connected load? Again, not done on these drawings.

Am I just being picky, or what? I know what I would expect if I was installing the job.

Thanks ahead for your comments.

RC
 
The amount and quality of information provided on the engineering drawings has been going down hill for a long time. I think a lot of that has to do with cutting costs. There is a lot of "design" required by the electrical contractor now because of the lack of details.

Yes, I see much of that as poor design, but none of it violates the code requirements.
90.2(B) addresses you point #3.
(B) Adequacy.
This Code contains provisions that are considered necessary for safety. Compliance therewith and proper maintenance result in an installation that is essentially free from hazard but not necessarily efficient, convenient, or adequate for good service or future expansion of electrical use.
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Some of it is the customers fault, I’ve worked with several engineering firms, and their biggest complaint is the customer failed to give any specs on the equipment to be installed other than voltage and breaker size required, so they have to guess at what the load actually is. And this is the big box stores, not some mom and pop businesses.
 
My client expected better. The project was for another apartment complex so all the loads were known exactly. I don't know what the fee was but based on his comments he sure didn't get his $ worth!

Two more comments. The drawings called for copper SE, prohibited aluminum!, which the client really wanted to use! The drawing also called for fusible mains and prohibited main breakers on the meter centers. I could go on!

My calculations required only 110 A apartment unit breakers in the meter center. The drawings called for 125A and 150A!
 
1. I do. For example, if a large room will have 9 receptacles along the walls, I go around the room showing, in order, circuits 1, 3, 5, 1, 3, 5, 1, 3, 5. I also show circuit numbers for motors, heaters, and other loads. I will match this info on the panel schedules (Revit has the ability to show this automatically). I never (unless so directed by the client, and even then I cringe) show arcs with tic marks on the plans (i.e., to depict the routing of wires and the number of phase, neutral, and ground wires associated with each arc).

2. I separate lights from receptacles. Lately, energy codes require having the ability to monitor energy used for lighting, receptacles, and other power equipment separately. So I am always seeing separate panels to serve nothing but lights. You might want to check whether these drawings are violating energy codes.

3. The specs from every client I can recall always called for 20% spare breakers and 20% spare load capacity for future load growth.

4. I do the same. Here again, since many engineering companies are using Revit these days, this is an available automatic feature.
 
Ragin Cajun said:
Two more comments. The drawings called for copper SE, prohibited aluminum!, which the client really wanted to use! The drawing also called for fusible mains and prohibited main breakers on the meter centers. I could go on!
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The engineer is not in charge of the design requirements; that role belongs to the owner (i,e., the client). If the plans do not incorporate the client's requirements, then flag that in your report.
 
#1 yes
#2 depends on voltage..
#3 depends on too many factors, money and practicality are 2..
#3 most certainly.
Was this a electrical engineer?
 
#2. Yes, although a breaker tripping and the lights going out doesn't seem likely enough to concern me. But I typically use #14 for lighting in commercial now, just a lot easier to work with and many of the compartments in these modern LED fixtures are annoyingly small. Plus the small load makes #12 not necessary generally.

#3 definitely have spare spaces. It's such a minimal cost.

#4 I know this is quite common , but I find it a complete waste of time and useless information, unless you have all very specific known loads. If I wanted to add load on the future I would not be using a worthless NEC calc. I would use 22.87 or more likely just my years of experience.
 
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