Healthcare electrical power

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1. Assessing the Health of Your Healthcare Facility’s Electrical Power Distribution System Make the most of your energySM 2. Summary Introduction…
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  • 1. Assessing the Health of Your Healthcare Facility’s Electrical Power Distribution System Make the most of your energySM
  • 2. Summary Introduction ..................................................................................................... p 4 References....................................................................................................... p 4 Why Perform an Assessment?.......................................................................... p 5 Assessment Process........................................................................................ p 6 • Who Should Perform PDS Assessments?...................................................... p 6 • Before Beginning the Assessment Process.................................................... p 6 – Workplace Safety....................................................................................... p 6 – Clarify “Scope of Work”.............................................................................. p 6 – What is Needed to Perform Assessments?................................................ p 7 After an Event “The Twenty Questions or Interview Period”............................... p 8 General On-site Assessments and Data Collection............................................ p 8 • A Starting Point............................................................................................. p 8 • Assessing Power Class Transformers............................................................ p 9 • Assessing Distribution Class Transformers..................................................... p 10 • Assessing Service Equipment........................................................................ p 10 • Assessing New Electrical Equipment Installations........................................... p 11 • Assessing Downstream Equipment................................................................ p 12 • Assessing Electrical Room Construction........................................................ p 12 • Assessing Emergency Generators................................................................. p 13 Assessments May Involve Some Testing........................................................... p 14 Loss Experience for Electrical Equipment.......................................................... p 14
  • 3. Assessing the Health of Your Healthcare Facility’s Electrical Power Distribution System An issue of vital concern in any healthcare environment is the “health” of the system infrastructures that works behind the scenes. Like any engineered system, electrical power distribution systems cannot be designed and constructed to indefinitely operate 100% of the time. Whether for a relatively new power system, or for an older existing installation, an assessment of the condition of the electrical power systems can mean the difference between an electrical system which operates as designed and intended as well as meets current electrical codes and standards and one that does not. This paper provides basic considerations that should be taken into account for assessments of the electrical power distribution systems within health-care facilities, including code compliances, bonding and grounding issues, ground fault protection requirements and surge protection needs. The procedures for carrying out assessments are also outlined, as well as the concerns and issues to be aware of that could compromise performance and/or safety of a healthcare facility. Charts are presented to show losses resulting from electrical equipment. Introduction • Power distribution systems or PDS is specifically referring to the electrical power system. • ANSI refers to the American National Standards Institute. • IEEE refers to the Institute for Electrical and Electronic Engineers, Inc. • NEMA refers to the National Electrical Equipment Manufacturers Association. • NFPA refers to the National Fire Protection Association. • NFPA 70 – 2008 Edition is commonly referred to as the National Electrical Code (NEC). • NFPA 70B – 2010 Edition: Recommended Practice for Electrical Equipment Maintenance. • NFPA 70E – 2009 Edition: Standard for Electrical Safety in the Workplaces • NFPA 99HB – 2005 Edition: Health Care Facilities Handbook This is the handbook edition of NFPA 99. NFPA 99 is the installation and performance requirements document for health care facilities and is the reference for The Joint Commission requirements. Most inspections by The Joint Commission will focus around the requirements of this document. • NFPA 110 – 2010 Edition: Standard for Emergency and Standby Power Systems • NFPA 111 – 2010 Edition: Standard on Stored Electrical Energy, Emergency and Standby Power Systems • NFPA 780 – 2008 Edition: Standard for the Installation of Lightning Protection Systems • IEEE Std C62.72™ – 2007: IEEE Guide for the Application of Surge-Protective Devices for Low-Voltage (1000 V or Less) AC Power Circuits References 4 | White paper on power distribution
  • 4. Assessing the Health of Your Healthcare Facility’s Electrical Power Distribution System There are numerous reasons why it may become necessary to perform an assessment of the Power Distribution System (PDS) of a specific healthcare facility or hospital. The most common reasons that PDS assessments are solicited and commissioned are usually associated with some event or events that occurred that caused the facility’s engineering or operations staff concerns, problems or stress. Some typical examples might be: • Tripping of protective devices. • Evaluation of devices or equipment as protective relays or circuit breakers to determine functionality and reliability. • Unexplainable dysfunction or unexpected operations of electrical equipment or controls relative to what has been usual and customary. • An electrical shock incident of a patient, visitor or staff member. • Abnormalities with the emergency power systems. However, these assessments are commissioned after the fact, are usually very limited in scope, and are principally focused only in ameliorating the specific concerns or conditions at hand. Another reason assessments are performed is that management may desire to have an independent review or second opinion of work performed by others. An independent assessment or inspection is often employed as a quality assurance method to review the contracted scope-of-work performed by a specific contractor. Assessments are often employed to determine if an existing or new electrical installation is in compliance with local electrical codes, the NEC, applicable IEEE® Standards, the equipment manufacturer’s installation and operational specifications, or best engineering and construction practices. To provide a broader and much more important perspective, comprehensive assessments by an experienced professional electrical engineer are best employed to provide information to management Why Perform an Assessment? on the “present state” of specific PDS. The results of such assessments are extremely valuable in determining the remaining usefulness or reliability of electrical equipment as well as the compatibility of existing equipment with newly installed or planned electrical equipment expansions. An understanding of the remaining usefulness or reliability of electrical equipment can provide management with an opportunity to adequately and proactively budget for a systematic replacement or retrofit of existing electrical equipment that might be aged, dysfunctional, outdated, under rated, unreliable or worn out. Interconnecting dissimilar electric equipment or circuit breakers provided by different electrical manufacturers can often result in poorly coordinated overcurrent protection or unwanted tripping conditions. Comprehensive assessments can be employed to construct a framework or guide for preventive maintenance programs and planned equipment enhancements or replacements. Occasionally PDS assessments are contracted and performed in order to fully understand the liability the system may present for a reliable hospital operation. As such PDS assessments can also provide for the following: • A means to determine the power distribution systems’ risk to future fdysfunctions. • A means to determine if there are any violations of electrical codes, electrical standards, or best practices. • A means to determine the cost of the necessary corrections or improvements. • A means to determine the necessary requirements to improve the present states of a PDS in order to extend the life and reliability of the equipment. Since September 11, 2001 some electrical codes have been revised to mandate assessments. For example, NEC 708.5(A), mandated that risk assessments be perform in all facilities classified as “Critical Operations Power Systems”. White paper on power distribtuion | 5
  • 5. Assessing the Health of Your Healthcare Facility’s Electrical Power Distribution System Assessment Process Who Should Perform PDS Assessments? The specific health care facilities, hospital or their assigned agent should interview and select professional electrical engineers and engineering services companies who are experienced in the design and installation of a wide variety of power distribution equipment. The selected electrical engineer should also be very familiar and well versed on all applicable electrical codes and standards specifically pertaining to electrical installations in health care facilities and hospitals. The selected electrical engineer or engineering service company should be able to produce a resume the reference prior assessment experiences. The selected professional electrical engineer(s) should be able to produce a report with a P.E. stamp from a licensed professional engineer in the state where the assessments will be performed. Before Beginning the Assessment Process Several things need to be considered before beginning any assessment process. These include workplace safety, scope of work and the items and tools necessary to perform the assessment. Workplace Safety Before starting the PDS assessments it is extremely importation to remember that safety is always of paramount concern and focus. Although it is the responsibility of facility management to assure the security at the facilities and to maintain a safe work environment, the electrical engineer performing the on-site assessments should be trained in accordance with NFPA 70E® , Standard for Electrical Safety in the Workplaces. Any electrical engineer performing the on-site assessments should reserve the right to discontinue any on-site activity if conditions are deemed to be unsafe. Safety procedures should be reviewed and understood by both the assessment party and the facility maintenance team. In addition, the electrical engineer performing the on-site assessments should be informed and made aware of any biological or other hazards that may be present during the course of his movements through and around the facilities. Security is also of importance. The facility management should arrange for security cards, identification badges and access to entry cards or security keys. The assessment engineering team also needs to be made aware of restricted areas or areas that may require staff personnel to provide an escort. Clarify “Scope of Work” Clarify and document the “scope of work” before the assessment process begins. Before beginning any on-site assessments, there should be a clear and documented understanding as to which equipment or portions of the PDS will be incorporated into an assessment program or study. The understanding takes the form of a scope of work document that is drafted with the input of the assessment engineer and management of the healthcare facilities. The scope of work needs to include all the equipment that is contracted and agrees to be incorporated into the assessment. Examples of such engineering functions that might also be included into an assessment could include, taking a wide assortment of different measurements, performing electrical or functional tests, installing metering or monitoring equipment, or operating a facility's equipment. Diligence in the beginning of any intended process is intended to prevent misunderstanding, distractions or expectations of tasks not clearly covered in the scope of work. It is also important for the electrical engineer performing any assessments to clearly identify any specific assistance from a facility’s operations and maintenance staff that may be need while on site. It is important to clearly inform the management of the healthcare facilities of any supportive roles that may be necessary by them, their associated staff, or their designated agents or contractors. 6 | White paper on power distribution
  • 6. Assessing the Health of Your Healthcare Facility’s Electrical Power Distribution System Some support activities that may be necessary for the healthcare management to provide are listed below: • Provide an individual authorized to resolve questions and coordinate customer activities, as required. • Provide an experienced electrical engineer or supervisor that is familiar with design documents and records to direct and assist Engineering Services personnel in any necessary equipment inspections. • Provide and expedite any badge processes necessary to required entry and escorts as necessary. • Inform the assessment engineer of any particular or specific safety requirements necessary to perform any activities on the customer's site. • Provide maintenance or operations staff personnel that are familiar with the existing power distribution systems who will accompany assessment engineer through the facilities and arrange for access to the applicable electrical equipment for inspections. • Assist the assessment engineer in the collection of applicable manufacturing and construction record data that accompanied the equipment. • Provide a timely response for all questions and submissions. • Assist the assessment engineer by providing keys access to the facility's electrical panels and equipment rooms, and the assistance of an electrician or facilities technician familiar with the physical location of electrical equipment, electrical circuits and specific loads. • Be responsible for collecting and provide all requested information concerning any or all specific ‘as-built’ electrical distribution system drawings and records. What is Needed to Perform Assessments? It is important that the electrical engineer performing the on-site assessments be effectively prepared before all work begins. This includes knowing what is needed to perform the on-site assessment. Below is a partial list of items or support that is often involved with or required to perform the on-site assessments: • Is special equipment required? • What personal protective equipment is required? • Are safety procedures required? • Is test equipment or diagnostic equipment required? • Is support personnel required? • Are outside contractors required? • Are power outages required? • Is special monitoring equipment required? • Are special tools required? • Are cameras allowed? White paper on power distribtuion | 7
  • 7. Assessing the Health of Your Healthcare Facility’s Electrical Power Distribution System After an Event — “The 20 Questions orInterviewPeriod” General On-Site Assessments and Data Collection If the on-site assessments are associated with a specific event, the selected engineer should start the process by interviewing the facility staff and all applicable or associated parties in order to gather as much historical data and information on the sequence of event as possible. Recollections and memories of different staff members or contractors often reveal different or conflicting descriptions of occurrences or sequences of events. Begin to quantify as many variables as possible for your assessments and analyses. Below are some examples: • What events occurred or did not occur? What equipment was involved? • When did the events occur? What date(s)? At what times and on which days did the event(s) occur? • What were the conditions and states of internal and external environmental condition? Were the internal spaces hot and humid? Were there any internal water or drain leaks? Were there thunder storms passing over head outside of the building at the time of the reported event? Was it raining outside? • What conditions or combination of conditions could have caused or contributed to the conditions reported? Begin to formulate conditions, pictures and scenarios in your mind. • Ask for and review all available and applicable documentation (one-line diagrams, inspection reports, test reports, original specifications, etc.) • What is the type and sequence of operation? • What is the history of construction? What is the history of facility operations? How long have the systems been in place? Were there any previous issues, incidents or concerns? • Determine and select the point to begin the inspections/assessments. Coordinate action plans with the customer. All power distribution systems are different and dynamic. The electrical engineer performing the on-site assessments should have a one-line diagram to study, become familiar with the normal electrical operations characteristics, building construction and layout, and limits of the equipment to be assessed. It is important to know what electrical codes were in place when the equipment or system was originally constructed or set in place. Not all municipalities and states employ exactly the same electrical codes and standards. Any special electrical code requirements in the specific location need to be taken into consideration. The dimensions of the facilities under assessment are also an important consideration. Are there any outside influences and conditions to consider such as switching operations by the local electrical utility, atmospheric disturbances or recent changes in configuration or operation of the facility’s internal electrical distribution systems? It is important to quantify as many variables as possible as part of any assessment program. A Starting Point The system configuration is based strictly on the specific secondary winding configuration of the power class or distribution class transformer supplying the service and exactly how it may or may not be referenced to earth. The system configuration is NOT based on the connection of any specific load or loads. Much of the data collected during the inspection processes are similar or identical to the data collection for short circuit study, time/current coordination study, or an arc flash study. The only difference is that the electrical engineer might be principally focusing on the installation and state of the equipment. 8 | White paper on power distribtuion
  • 8. Assessing the Health of Your Healthcare Facility’s Electrical Power Distribution System For example: • How many sources of power (transformers, generators, UPS units, back up batteries, MG sets, solar panel arrays, wind generators, transfer switches)? • Who is the local electrical utility or electrical service provider? • Who owns the service transformers? • How are the service transformers, generators, UPSs or MGs configured or referenced to earth? Assessing Power Class Transformers Following is a list of specific things to look for when assessing power class transformers (greater than 500 KVA): • What is the size of the transformer in KVA? • What are the primary and secondary winding configurations? • What are the primary and secondary voltages? • What is the present tap setting? • Does the transformer have a “no load” tap changer or a “load” tap changer? • What is the percent impedance (%Z) of the transformer? • What is the condition of transformer? • What is the cooling means for the transformer? • What is the temperature gauge reading (present temperature and the maximum temperature indicated)? •
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