Download Electrical Design Reviews - Building Commissioning Association

Electrical Design Reviews
Don Zerrip
Senior Consultant
CxGBS®
AIA Quality Assurance
Portland Energy Conservation, Inc is a registered provider with The
American Institute of Architects Continuing Education Systems. Credit
earned on completion of this program will be reported to CES Records
for AIA members. Certificates of Completion for non-AIA members are
available on request.
This program is registered with the AIA/CES for continuing
professional education. As such, it does not include content that may
be deemed or construed to be an approval or endorsement by the AIA
of any material of construction or any method or manner of handling,
using, distributing, or dealing in any material or product. Questions
related to specific materials, methods, and services will be addressed
at the conclusion of this presentation.
AIA Quality Assurance
Learning Objectives
1. Why perform electrical design reviews.
2. Review successful tools used to perform electrical
design reviews.
3. Where does the design review fit in the commissioning
process.
4. Using an example, understand successful methods used
and detail needed to perform a review.
5. Results and issues noted in a sampling of electrical
design reviews performed.
Electrical Design Reviews
Why commission the electrical design?
• Design shortcomings can easily be corrected
at the design stage
• It is only “paper” at the design stage
• Minimal cost when discovered early
• Reduces risk across the board
• There are indications of mistakes being made
at the design stage
Electrical Design Reviews
Not doing electrical design reviews?
• Yields construction by design and not by
intent
• Errors that exist might be corrected in the field
• There could be the long term results on
○ Safety
○ Efficiency
○ Cost
Electrical Design Reviews
Goals
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Increase Quality and Safety
Reduce Risk
Minimize Change Orders
Increase Reliability, MTBF
Decrease MTTR
Check Drawings Against Project Objectives
Electrical Design Reviews
Comments
• This is not a code review but rather as the
commissioning agent you are a third party
working as an independent advocate of the
building owner.
Electrical Design Reviews
The reviewer:
• Should have significant design and hands-on
experience in construction, installation, and
maintenance of buildings and equipment.
• Provides another set of experienced eyes
reviewing drawings for feasibility, consistency,
and completeness.
Electrical Design Reviews
Tools
• Drawings and specifications
○ The appropriate set for the task (SD, DD, CD)
○ You need all of the drawings (A, M, E, ...
○ Prefer electronic (“pdf” format)
- Good quality (usually not a problem)
- Sequential sheets in one PDF file
○ Paper
- Full size
- Large space, heavy, tend to push you for paper notes
Electrical Design Reviews
Equipment for Electronic Documents
• Good computer – large resolution, memory, disk
space
○ Apple 24” iMac with 1920x1200 resolution
• Second display
○ Samsung 24” T240 with 1920x1200 resolution
• Wireless keyboard
• Wireless mouse
Electrical Design Reviews
Other useful tools
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Internet access
Calculator
Reference material
Printer
Magnifying glass
Colored pens
Electrical Design Reviews
Electrical Design Reviews
Software
• Adobe Acrobat Reader and Apple Preview
○ Both allow opening PDF files but differ in features
○ Preview can easily combine single page files into
one document
○ Adobe Reader has a Pan & Zoom tool to view
smaller sections of a drawing
• Microsoft Word for Mac 2008
○ Generally compatible with Microsoft Word for
Windows with the exception of macros
Electrical Design Reviews
Word
Preview
Adobe Acrobat
Electrical Design Reviews
Three Project Stages for Design Review
• SD – Schematic Design
• DD – Design Development
• CD – Construction Documents
Electrical Design Reviews
Performing the Design Review
• Understand what has been contracted
• Read through the Project Specifications
• Check drawings against the drawing index
○ Complete set and most current version
Electrical Design Reviews
Site Plans and Building Design
Electrical Design Reviews
A key element in
the electrical design
is the Power Riser
or One-Line...
It may be simple
Electrical Design Reviews
or a bit more complex . . .
Electrical Design Reviews
Voltages in building wiring
• Typical are 480VAC or 208VAC in a Δ
winding
• Typical are 480/277 VAC or 208/120 VAC in a
Wye (Y) winding
• Voltages typically stay the same or are
reduced from the source to the user
• As voltages go down the currents go up for
the same power and so does the circuit
losses (resistance)
Electrical Design Reviews
Start with electrical distribution system
• Incoming power path
○ Switchboards, panel boards, transformers, etc.
○ Voltage, size, circuit protection, cable sizes
• Switchboards and panel boards
○ One-lines match the schedules
○ Current and voltage ratings
○ Breakers, fuses, or MLO
○ Circuit balance on multi-phase circuits
Electrical Design Reviews
Work through the drawings for …
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Lighting
Grounding
Fire alarm systems
Exterior lighting
Generator
ATS
Electrical Design Reviews
Transformer and Wiring Example
Electrical Design Reviews
Transformers
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Power capacity
Type
Voltage
Correct number of conductors
○ Delta incoming – 3W + ground
○ Wye – 4W conductors + ground
Electrical Design Reviews
Transformer
Electrical Design Reviews
Transformer Power Check:
Three-Phase Kilowatts = Volts x Amps x PF x 1.732
1000
Transformer KWmax = 480 x 175 x 1.0 x 1.732 / 1000
KWmax = 145.5 KW
Electrical Design Reviews
Transformer Schedule
Protection = 145.5/112.5
= 129% of rated load
Electrical Design Reviews
Circuit Voltages
Electrical Design Reviews
Transformer Schedule
Electrical Design Reviews
Circuit Protection
Electrical Design Reviews
Circuit Protection
Electrical Design Reviews
Number of Conductors
Electrical Design Reviews
Cables
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9
10
25
26
Electrical Design Reviews
Cables
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9
10
25
26
3 #2/0 & 1#6 GND
4-600KCMIL & 1#3 GND
3 #1 & 1#6 GND
4 #4/0 & 1#4
Electrical Design Reviews
Cables
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9
10
25
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3 #2/0 & 1#6 GND
4-600KCMIL & 1#3 GND
3 #1 & 1#6 GND
4 #4/0 & 1#4
Electrical Design Reviews
Number of Conductors
Electrical Design Reviews
Panels and Circuits
Electrical Design Reviews
Not all observations noted are panels and circuits
You are standing here.
Where is your exit?
Electrical Design Reviews
Electrical Design Reviews
What happens with the findings?
• Assembled with other disciplines results
• Forwarded with recommendations to design
team and copied to the owner
• Design responses are returned and each
issue is brought to resolution
• All need resolution prior to contract award
Donald Zerrip
3075 Breckinridge Blvd.
Duluth, GA 30096