Critical Power: NFPA 110: Standard for Emergency and Standby Power

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Learning Objectives

•The audience will understand NFPA 110: Standard for Emergency and Standby Power Systems; NFPA 70: National Electrical Code; and how they work together

•Attendees will learn the changes from the 2010 edition of NFPA 110

•Viewers will understand the criteria for EPSS classification

•Viewers will learn how to minimize the impact of EPSS testing

Tom Divine, PE, Smith Seckman Reid Inc.,Houston, Tex.

Kenneth Kutsmeda, PE, LEED AP, Jacobs Engineering,Philadelphia, Penn.

Moderator: Jack Smith, Consulting-Specifying Engineer and Pure Power, CFE Media, LLC

Presenters:

Critical Power: NFPA 110: Standard for Emergency and Standby Power

Tom Divine, PE, Smith Seckman Reid Inc.,

Houston, Tex.

Kenneth Kutsmeda, PE, LEED AP, Jacobs Engineering,Philadelphia, Penn.

Applicable NFPA codes and standards associated with EPSS

• NFPA 70: National Electrical Code (NEC)

• NFPA 110: Standard for Emergency and Standby Power Systems

• NFPA 99: Standard for Health Care Facilities.

Emergency power supply system (EPSS) is the total system for distributing electrical power within a facility when the normal power source is interrupted.

• Emergency Power Source (EPS)

• Transfer Switching Device

• Overcurrent Protection

• Control Systems

NFPA 70: National Electrical Code (NEC)

Standard for the safe installation of electrical wiring and equipment in the U.S.

• Article 700: Emergency Systems

• Article 701: Legally Required Standby Systems

• Article 702: Optional Standby Systems

• Article 708: Critical Operations Power Systems

NEC Article 700: Emergency Systems

Systems intended to supply illumination and power to equipment essential for safety to human life.

Examples:

• Egress lighting• Life support systems• Elevators• Fire detection and fire alarm• Fire pumps.

NEC Article 700: Emergency Systems

Requirements:

• Start and transfer automatically

• Dedicated transfer equipment

• Available for load in 10 sec

• Point of distribution must have physical separation

• Emergency system wiring shall be independent of all other wiring

• Selective coordination

• AHJ must witness testing.

NEC Article 700: Emergency Systems

Alternate source of power must be a storage battery, generator set, UPS, separate service, or fuel cell system:• 2 hr on site fuel storage• 90 min battery capacity

Additional requirements for assembly occupancies over 1,000 persons or buildings higher than 75 ft:• Fire Protection for Feeder Circuit Wiring• Fire Protection for Feeder Equipment

NEC Article 701: Legally Required Standby

Systems intended to supply power to aid firefighting, rescue operation, and control of health hazards.

Examples:• Smoke removal systems• Communications systems• Ventilation systems• Sewage disposal systems• Industrial processes that when stopped could

create hazards.

NEC Article 701: Legally Required Standby

Requirements:

• Start automatically

• Available for load in 60 sec

• 2 hr on-site fuel storage

• AHJ must witness testing.

NEC indicates that generators used for emergency and legally required systems shall not be solely dependent on public source (gas line) for fuel supply unless where acceptable to the AHJ.

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NEC Article 702: Optional standby systems

Systems intended to supply power to prevent physical discomfort, interruption of an industrial process, damage to equipment, or disruption of business.

Examples:• Refrigerators/freezers• Data processing• Farms• Commercial buildings• Carnivals.

Requirements:

• Manual or automatic start• No available for load time requirements• No on-site fuel storage requirements

Portable generators are acceptable to be connected to an optional standby power system.

NEC Article 702: Optional standby systems

Emergency/legally required:

Designed to safely evacuate people and prevent hazards by keeping portions of the system operating for a certain period of time.

Critical operations/mission critical:

Designed to keep the entire facility or critical components operating for the complete extent of the outage.

• Availability: System must function when required (24x7)

• Reliability: System must not fail. If a failure occurs, the system must respond and recover quickly.

• Security: System must provide protection against an attack, either human or naturally caused.

“A mission critical system is a system that is essential to the survival of a business or organization. When a mission critical system fails or is interrupted, operations are significantly impacted.”

Types of mission critical facilities

Private: business continuity

Attributes defined by the business based on its business case

• Business enterprise data centers

• Financial data centers and trading

Public safety

Attributes defined by code and governed by the agency having jurisdiction (AHJ)

• Emergency call centers

• Police and fire stations

• National security.

Private business continuity

Facilities where the levels of availability and reliability are dictated by the business case.

• Acceptable level of risk

• Downtime for maintenance

• Required degree of redundancy

• Protection against failures.

Private business continuity

• Low tolerance for risk

• No downtime

• High level of reliability.

Redundant components/generators (N+1, N+2, or 2N)

Allows for one of the components or generators to be taken offline for maintenance or failure of one generator without affecting the operation of the facility.

Public safety facilities

Facilities where the levels of availability and reliability are required to protect the public safety, public health, and national security.

NEC Article 708: Critical Operations Power Systems (COPS)

• Addresses homeland security issues for mission critical facilities.

• Provides requirements for the installation, operation, control, and maintenance of electrical equipment serving critical operation areas that must remain operational during a natural or human caused disaster.

• Critical operations power systems are installed in vital facilities that if incapacitated would disrupt national security, public health, and public safety.

• Provide an alternate power supply • Alternate power shall have on-site fuel capacity to

operate for 72 hr• Generator can’t be dependent on public utility gas for

fuel• Redundant equipment is required, or at minimum, the

means, to connect roll up equipment• Equipment must be located above the 100 yr flood plain.

NEC Article 708: Requirements for standby power

• COPS system wiring shall be independent of all other wiring

• Fire protection for feeders• Selective coordination• Documented commissioning• Documented maintenance plan.

NEC Article 708: Requirements for standby power

Examples of facilities that would use COPS:

• Police and fire stations• Emergency management centers• Emergency call centers• Government facilities involved with

national security• Financial facilities involved with

national economic security• Hospitals.

NEC Article 517: Scope

• Scope: Health care facilities for humans• Special requirements

– Wiring, protection, grounding, x-ray, operating rooms

• “Essential electrical system”• Amends requirements of other articles,

particularly Article 700.

NEC Article 517: Key definitions• Essential electrical system:

– Alternate source, usually standby generator– Plus distribution and ancillary equipment

• Structure under NEC 2010– Emergency system

• Life safety branch• Critical branch

– Equipment system

NEC Article 517: Structure

• Life safety branch: 517.32– Getting out of the building– Plus a couple of other things– Prescriptive and proscriptive

• Critical branch: 517.33– Patient care– Effective hospital operations– Less restrictive that life safety branch

NEC Article 517: Structure

• Equipment system: 517.34– Delayed connection– Some equipment required, some optional– In practice, mostly HVAC.

NEC Article 517: Special rule

• Generators are sized for demand load – 517.30(D)

• 700.4 and 701.4 require sizing for connected load

• Potential for generator damage from light loading: wet stacking.

NEC Article 517: Wet Stacking

NFPA 110: Standard for Emergency and Standby Power Systems

• Describes requirements for performance• Doesn’t drive requirement for system: 1.2.1

– Building codes– NFPA 70: NEC– NFPA 99: Health Care Facilities Code– Operational requirements

NFPA 110: Scope

• Installation: location, equipment, accessories• Maintenance: inspections, frequency, records• Testing: installation and maintenance• System characteristics: transfer switches, fuel

system• Scope ends at load terminals of transfer

switches.

NFPA 110: Key abbreviations

• Emergency power supply: EPS– Source, usually generator

• Emergency power supply system: EPSS– Everything between the generator and the

load terminals of the transfer switches.

NFPA 110: Inspection and testing

• Installation testing: EPSS• Weekly inspection: EPSS• Monthly load testing: EPSS• Transfer switches operated monthly• More extensive requirements for level 1 EPSS

Code changes: NFPA 110 - 2013

• 6.1.6: Permits electrically interlocked circuit breakers as transfer switch for medium-voltage mechanical equipment

• 8.1.2: Requires consideration of portable generator when type criteria can’t be met

• 8.4.8: Requires that only “qualified persons” perform maintenance, changed from “a properly instructed individual.”

Code changes: NFPA 110 - 2013

Annex: Not exactly code• A.7.9.1.2: Added description of fuel

testing• A.7.13.4.3: Added description of standby

and prime generator ratings• A.8.4.2: Requires a permanent record of

the generator rating to be readily available.

Code changes: NEC 517 - 2014

• Definition of “emergency system” deleted– Essential system composed of three

branches: life safety, critical, equipment– In practice, has little effect

• Defines selective coordination requirement at 0.1 sec

• Purpose: Harmonization with NFPA 99, which no longer uses the term.

NFPA 110: Standard for Emergency and Standby Power Systems

Defines how emergency and standby power systems are to be installed and tested. It contains requirements for energy sources, transfer equipment, and installation and environmental considerations.

NFPA 110 divides emergency power systems into three categories:

•Type

•Class

•Level

The type refers to the maximum time that an emergency power system can remain unpowered after a failure of the normal source.

NFPA 110: Standard for Emergency and Standby Power Systems

The class of an emergency power system refers to the minimum time, in hours, for which the system is designed to operate at its rated load without being refueled or recharged.

NFPA 110: Standard for Emergency and Standby Power Systems

The Level of an emergency power system refers to the level of equipment installation, performance, and maintenance requirements.

NFPA 110: Standard for Emergency and Standby Power Systems

NFPA 110: Testing requirements

Installation testing• Start system and record performance• Full-load test: 2 hr

– 30% of nameplate kW for ½ hr– 50% for ½ hr– 100% for 1 hr

• Engine crank and battery tests• Detailed records.

Monthly load testing• Requirement covers entire EPSS• Run generator under load

– Special requirements for diesel units

• Exercise transfer switches– Round trip to emergency position and back.

NFPA 110: Testing requirements

• Monthly load testing – diesel generators– 30 min minimum– Recommended exhaust temperature, or 30%

of nameplate kW rating

• Otherwise, annual test with supplemental load, for ½ hr at 50%, 1 hr at 75%

• Level 1: 100% test for lesser of Class duration or 4 hr, every 3 yr, at 30% and at recommended exhaust temperature.

NFPA 110: Testing requirements

Monthly load testing – diesel generators• 30 min minimum• Recommended exhaust temperature, or

30% of nameplate kW rating• Otherwise, annual test with supplemental

load, for ½ hr at 50%, 1 hr at 75%• Level 1: Annual 100% test for lesser of

Class duration or 4 hr.

NFPA 110: Testing requirements

NFPA 110: Testing strategies

• Transfer less sensitive load, if adequate• Manage mechanical systems to increase

load for test– Let chilled water temperature drift upward

before load testing

• Complete normal power system shutdown• Load bank: start with facility load,

supplement with load bank.

Because of the dependency on the generator to keep the facility operating, all generator systems for mission critical facilities are fully tested and commissioned before they are put into service.

Factory witness testing

Site acceptance testing

• Load steps

• Transients response

• Heat run

Integrated system testing

• Test all system together

• Pull the plug.

Maintenance recommendations

• Implement a facility preventive maintenance program

• Follow NETA recommendations, perform maintenance and testing of generators every 12 mo

• Exercise the generator regularly

• Load test generator

• Keep an inventory of spare parts

• Properly train all operators

• Periodic analysis of lube oil and fuel oil.

During Hurricane Sandy there were many facilities in the Northeast that relied on their standby power systems for multiple days to keep the facility operating.

Lessons learned:

• Locate above the flood plain

• Adequate on-site fuel supply

• Means to change filters while operating.

Locate generators and other standby power system distribution equipment above the flood plain.

• Generators, transfer switches, and electrical equipment can’t operate if under water

• During Hurricane Sandy, areas did see flooding above 100 yr flood plain.

• Recommend locating standby equipment above the 100 yr flood plain or above the 500 yr flood plain, if possible.

Have adequate supply of on-site fuel storage

• Water subsided in about a day but the debris and damage made it difficult to deliver fuel (even for those facilities with emergency contracts)

• On average, it was about 3 days before facilities could get fuel delivered

• Recommend minimum of 72 hr fuel storage.

Provide means to change filters out while operating

• Fuel that was delivered was contaminated with water and debris

• Facilities operators were changing filters every couple of hours to keep the systems from clogging

• Recommend installing dual-header filter systems with transfer valve that allows for filter replacement while engine is operating

• Consider fuel polishing system.

Classification summary

Emergency and Level 1 are systems essential to the safety of human life.

Legally required and Level 2 are systems less critical to human life, but if stopped could create hazards or hamper rescue and fire fighting operations.

Critical systems have a requirement to remain operational under all conditions and demand a higher level of reliability and availability.

Overall goal of emergency and standby power systems is to provide power when there is a loss of utility.

• NFPA 70: National Electrical Code (NEC)

• NFPA 110: Standard for Emergency and Standby Power Systems

• NFPA 99: Standard for Health Care Facilities

Codes and Standards References from Today’s Webcast

• NFPA 70: National Electrical Code

• NFPA 99: Health Care Facilities Code

• NFPA 110: Standard for Emergency and Standby Power Systems

Tom Divine, PE, Smith Seckman Reid Inc.,Houston, Tex.

Kenneth Kutsmeda, PE, LEED AP, Jacobs Engineering,Philadelphia, Penn.

Moderator: Jack Smith, Consulting-Specifying Engineer and Pure Power, CFE Media, LLC

Presenters:

Webcasts and Research

• Critical power: Generators and generator system design

• Critical power: Integrating renewable power into buildings

• Critical power: Circuit protection in health care facilities

• Critical power: Standby power for mission critical facilities

• 2013 Electrical and Power study

Critical Power: NFPA 110: Standard for Emergency and Standby Power

Sponsored by:

Join the discussion about this Webcast on Twitter at #CSENFPA110