Electrical Systems Commissioning

Transcription

1 Electrical Systems Commissioning Catherine Melander, Questions & Solutions Engineering 21 st National Conference on Building Commissioning

2 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. 21 st NCBC Conference

3 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.. 21 st NCBC Conference

4 Learning Objectives 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. 21 st NCBC Conference

5 MAJOR HOSPITAL PROJECTS Mechanical and Electrical Systems Commissioned Maple Grove Hospital Maple Grove, MN University of Minnesota Amplatz Children s Hospital, Minneapolis, MN 21 st NCBC Conference

6 MAJOR HOSPITAL PROJECTS Mechanical and Electrical Systems Commissioned University of Chicago Medical Center - Chicago, IL Owensboro Medical Health Center Owensboro, KY 21 st NCBC Conference

7 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.

8 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:

9 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.

10 Introduction Electrical and Mechanical Integration We will also discuss some common mechanical systems interface issues found during electrical testing. 21 st NCBC Conference

11 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 nonshed-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.

12 Essential Power System What failure occurred Case Study: The sequence was not defined prior to testing thus the system was not programmed. During the overload test a P1 load was shed When Failure occurred during sequence of operations testing. Why Sequence of Operations not provided or poorly defined. Load shed sequence not clearly defined. Where in Cx process Define sequence of operations early in project during Design Phase Test sequence of operations including load shed sequence. Verify Priority 1 loads don t shed

13 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

14 Normal Power System What failure occurred Upon 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. Why During field connection of shipping splits, control wiring harness connector was not connected or wiring connections were incorrectly made by field installer. Where in Cx process Field observation and testing phase is only place to find this error and prevent a failure.

15 Fuel Oil System What failure occurred Fuel leaks, one large enough to delay essential power system testing for one month When Failure occurred during prior to functional testing of emergency power system. Fuel Oil system was started up but not functionally tested. Why System 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.

16 Fuel Oil System Where in Cx process Design/Submittal Review process Functional Testing Mechanical/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.

17 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.

18 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 power Occupant equipment responds as expected under emergency power. Mechanical and other building systems recover as expected upon restoration of Utility/Normal power source.

19 Loss of Power Response (Blackout) Test When Loss of Power Response test should be conducted after all electrical & mechanical systems have been commissioned. Why System interactions and issues are observed that often would not be observed when conducting functional testing of individual systems.

20 Loss of Power Response (Blackout) Test Lessons Learned What Mechanical system restart sequences did not function as the Building Automation System (BAS) did not know that it was operating under alternate power source. When Consider observing mechanical systems operation and proper restart during earlier interim Essential Power System testing.

21 Loss of Power Response (Blackout) Test Lessons Learned What Operating Rooms were unable to maintain proper pressurization during and following a power outage. When Define 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.

22 Loss of Power Response (Blackout) Test Lessons Learned What Security access system not operable as not powered by Essential Power System When Discovered 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.

23 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%. Why BAS is powered off of an Uninterruptible Power Supply (UPS) and does not know that systems it is controlling are without power. When Discovered during mini LOPR test.

24 Electrical Power System Commissioning Questions?

25 THANK YOU