Electrical Systems Commissioning - BCxA€¦ · Presentation Description This presentation will...
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Catherine Melander, Questions & Solutions Engineering Electrical Systems Commissioning 21 st National Conference on Building Commissioning
Transcript of Electrical Systems Commissioning - BCxA€¦ · Presentation Description This presentation will...
Catherine Melander, Questions & Solutions Engineering
Electrical Systems Commissioning
21st National Conference on Building Commissioning
AIA Quality Assurance
The Building Commissioning Association is a Registered Provider with The American Institute of Architects Continuing Education Systems (AIA/CES). Credit(s) earned on completion of this program will be reported to AIA/CES for AIA members. Certificates of Completion for both AIA members and non-AIA members are available upon request.
This program is registered with 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.
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Presentation Description
This presentation will explore the what, when why and how of common issues found during commissioning of electrical power systems, many of which are not detectible until a failure or fault occurs. In addition, the presentation will look at the electrical/mechanical system interfaces that are critical in the emergency power system testing and provide examples of the types of mechanical problems discovered during emergency power system testing..
21st NCBC Conference
At the end of this session, participants will be able to:
1. Identify common failures found during electrical system functional testing.
2. Identify where in the commissioning process common failures could be avoided during future commissioning.
3. Understand common mechanical systems interface issues found during electrical testing.
4. Apply electrical system commissioning lessons learned to future projects.
Learning Objectives
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University of Minnesota Amplatz Children’s Hospital, Minneapolis, MN
Maple Grove HospitalMaple Grove, MN
21st NCBC Conference
MAJOR HOSPITAL PROJECTSMechanical and Electrical Systems Commissioned
University of Chicago Medical Center - Chicago, IL
Owensboro Medical Health Center Owensboro, KY
21st NCBC Conference
MAJOR HOSPITAL PROJECTS Mechanical and Electrical Systems Commissioned
Electrical Power System Commissioning
Commissioning of Electrical Power systems is important because most electrical failures often occur as catastrophic events and are not detected until a fault or failure occurs.
National Electrical Code now requires commissioning of Critical Operations Power Systems (COPS). Ref: NEC Code, Article 708.
Electrical Power System Commissioning
What, When, How & Where
We will discuss electrical failures and issues we have found when commissioning electrical and emergency power systems.
We will review some project examples to demonstrate:
Electrical Power System Commissioning
WHAT failure or issue occurred
WHEN did failure occur
HOW was the problem resolved
WHERE in the Cx process can we best affect these electrical issues.
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We will also discuss some common mechanical systems interface issues found during electrical testing.
IntroductionElectrical and Mechanical Integration
Essential Power System
Essential Power system
• Four – 2000kW Generators• Paralleling Switchgear• Multiple Automatic Transfer Switches serving
Priority 1 and Priority 2 loads
Priority 1 loads – Life Safety and Critical “non-shed-able” loads required to be transferred to Essential (Generator) power within 10 seconds. Priority 2 loads – Loads requiring restoration of power but not within a specified maximum time interval like Priority 1 loads. These are “shed-able” loads and consist of Equipment Branch system loads.
Essential Power System
What failure occurredCase Study: The sequence was not defined prior to testing thus the system was not programmed. During the overload test a P1 load was shedWhen Failure occurred during sequence of operations testing. WhySequence of Operations not provided or poorly defined. Load shed sequence not clearly defined. Where in Cx processDefine sequence of operations early in project –during Design PhaseTest sequence of operations including load shed sequence. Verify Priority 1 loads don’t shed
Normal Power System
Main Tie Main Switchgear
• 480 Volt Double Ended Switchgear• Main Tie Main Configuration• Mains normally open, Tie Closed• Upon loss of power, affected main trips
open and tie closes automatically restoring normal power to loads.
• Switchgear shipped in sections –equipment and control wiring field connections required
Normal Power System
What failure occurredUpon loss of utility side A, control voltage throwover scheme failed to transfer control power to A Bus, causing sustained loss of normal power to A Bus loads. When Failure occurred during functional testing by simulating loss of side A and side B utility power. WhyDuring field connection of shipping splits, control wiring harness connector was not connected or wiring connections were incorrectly made by field installer.Where in Cx processField observation and testing phase is only place to find this error and prevent a failure.
Fuel Oil System
What failure occurredFuel leaks, one large enough to delay essential power system testing for one monthWhen Failure occurred during prior to functional testing of emergency power system. Fuel Oil system was started up but not functionally tested.
WhySystem left on auto mode and cold temperatures cause fuel recirculation to start. Undersized fuel pump could not remove fuel oil from day tanks fast enough to keep up with supply pumps.
Fuel Oil System
Where in Cx processDesign/Submittal Review processFunctional TestingMechanical/Electrical Lessons Learned. • Critical to functionally test fuel oil system
and other supporting systems prior to load bank testing of generators.
• Building Automation System (BAS network ideally too) must be ready early
• Early coordination with Controls Contractor • Electrical testing usually scheduled relatively
early in construction schedule.• Early scheduling effort particularly for
systems with heavy mechanical/electrical interface.
Loss of Power Response (LOPR or Blackout) Test
What is a LOPR Test?Not just an “electrical systems test” but a Building Wide test.
LOPR Confirms: Emergency Power system responds as expected upon loss of Utility power.Mechanical equipment, electrical and life safety loads restore to normal operation upon restoration of alternate power source.
Loss of Power Response (Blackout) Test
What is a LOPR Response Test?Other special building systems (BAS, Nurse Call, Security & Access, Med Gas, lighting, Information Technology, telecom, critical outlets, etc.) restore to normal operation as building is transferred to emergency powerOccupant equipment responds as expected under emergency power.
Mechanical and other building systems recover as expected upon restoration of Utility/Normal power source.
Loss of Power Response (Blackout) Test
When Loss of Power Response test should be conducted after all electrical & mechanical systems have been commissioned.
WhySystem interactions and issues are observed that often would not be observed when conducting functional testing of individual systems.
Loss of Power Response (Blackout) Test
Lessons Learned
WhatMechanical system restart sequences did not function as the Building Automation System (BAS) did not “know” that it was operating under alternate power source.WhenConsider observing mechanical systems operation and proper restart during earlier interim Essential Power System testing.
Loss of Power Response (Blackout) Test
Lessons Learned What Operating Rooms were unable to maintain proper pressurization during and following a power outage.
WhenDefine the requirements early in the project as part of the Owner’s Project Requirements (OPR) documentation. Do all parties (including the design professional) understand the requirements of the system?Functionally test during mechanical testing and during Loss Of Power Response testing.
Loss of Power Response (Blackout) Test
Lessons Learned What Security access system not operable as not powered by Essential Power System
WhenDiscovered during LOPR test. Ideally, as part of functional testing of the Security/Access systems, would perform a mini LOPR test.When planning LOPR test, make sure to provide for access to spaces with hard keys in case of failure of security and other electronic systems.
Loss of Power Response (Blackout) Test
Lessons Learned What Chillers were driven to 100% since controls were operating on UPS and chillers were non responsive. Once chiller emergency power restored they drove to 100%. WhyBAS is powered off of an Uninterruptible Power Supply (UPS) and does not “know” that systems it is controlling are without power.WhenDiscovered during mini LOPR test.
Electrical Power System Commissioning
Questions?
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