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Don ZerripSenior ConsultantCxGBS®

Electrical Design Reviews

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.

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.

AIA Quality Assurance

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•

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•

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 Reviewsor 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 …•

Lighting

Grounding•

Fire alarm systems

Exterior lighting•

Generator

ATS

Electrical Design Reviews

Transformer and Wiring Example

Electrical Design Reviews

Transformers•

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 1.7321000

Transformer KWmax

= 480 x 175 x 1.0 x 1.732 / 1000KWmax

= 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•

9

10•

25

26

Electrical Design Reviews

Cables•

9 3 #2/0 & 1#6 GND

10 4-600KCMIL & 1#3 GND•

25 3 #1 & 1#6 GND

26 4 #4/0 & 1#4

Electrical Design Reviews

Cables•

9 3 #2/0 & 1#6 GND

10 4-600KCMIL & 1#3 GND•

25 3 #1 & 1#6 GND

26 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 circuitsYou 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

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