national electrical code (nec) 2017 requirements for surge

National Electrical Code (NEC) 2017 Requirements for Surge Protective Devices

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In the United States, The National Electrical Code® (NEC®) sets forth installation requirements for electrical systems and equipment, including Surge Protective Devices (SPDs).1 The NEC provides guidance regarding where SPDs should and should not be used and how they may be installed in electrical power distribution systems. The following narrative identifies and describes key provisions of the NEC.

CODE ADOPTION

In any review of the NEC, it is important to understand its revision and adoption process. The NEC is revised once every three years, then republished as a new edition. In the United States, any new edition becomes effective locally after it is formally adopted by a state or local agency having jurisdiction. Because the timing of adoption by each state differs, four different editions of the NEC were in effect in the United States on August 1, 2018. In addition, three states had not adopted any edition for state-wide use. The status of effective editions is shown in Figure 1.

National Electrical Code (NEC) 2017 Requirements for Surge Protective Devices

Figure 1: National Electrical Code Editions in Effect on August 1, 20182

0.9364 in

HI

CA

NV

OR

WA

IDWY

MT ND

SD

NE

COUT

AZ NM

TX

OK

KS

LA

AR

MO

IA

MN

WIMI

IL IN OH

KY

TN

MS AL GASC

NC

VA MDDE

MA

CT

NY

PARI

VTNH ME

FL

WV

AK

NJ

2017 NEC®

2014 NEC®

2011 NEC®

2008 NEC®

No Statewide NEC® Adoption

1 National Fire Protection Association, NFPA 70 - National Electrical Code®, Fourteenth Edition, 2017. Quincy, Massachusetts, 2016.2 National Fire Protection Association, National Electrical Code in Effect August 1, 2018. https://www.nfpa.org/NEC/NEC-adoption-and-use/NEC-adoption-maps, viewed 8/28/18.

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Most states that have not adopted the latest version of the NEC have initiated a review process for adopting an edition of the code. While the latest edition of the code may not be required locally when a project is designed, many NEC changes are made to improve safety. Because updates typically do not conflict with older provisions, designing to the latest edition can improve overall facility design. Applicable local codes should also be reviewed.

For instance, Pennsylvania currently uses the 2008 NEC, and is presently reviewing the 2014 edition for adoption. When planning projects, it is important to know the edition in effect for the project location and to monitor the status of adoption processes in the project location.

ESSENTIAL NEC PROVISIONS

Article 285 – Surge Protective Devices

Essential provisions regarding SPDs have been part of the NEC through several editions. Added in 2002 and amended thereafter, Article 285 – Surge Protective Devices, 1000 Volts or Less describes types of SPDs and the corresponding locations for their installation. The article also presents basic but important provisions regarding the use of SPDs. These include requirements to connect SPDs to each ungrounded connector at the point of use;3 installing only listed SPDs;4 and using leads that are no longer than necessary and avoiding unnecessary bends.5

Article 285 also prohibits certain uses of SPDs, and prohibits installing SPDs where voltages or fault currents exceed device ratings.6,7 Those ratings include the Short-Circuit Current Rating required by Article 285.7. These ratings can be found on a manufacturer’s product data sheet. A data sheet example is shown in Figure 2.

3 National Fire Protection Association, NFPA 70 - National Electrical Code®, Fourteenth Edition, 2017. Quincy, Massachusetts, 2016. p. 70-132.4 Ibid.5 Ibid. p. 70-133.6 Ibid. p. 70-132.7 Ibid.

Figure 2: Manufacturer’s data sheets provide ratings for each SPD model.

Model 460 Ordering OptionsConnection Monitoring Surge Current Per Phase Base Catalog Number Enclosure Dimensions

Lugs(#14 – #2)

Counter, Lights, Alarm, Contacts

100kA460P10ACCE0

12 x 12 x 7 in.NEMA 1/12/3R/4(steel)

200kA460P20ACCE0

300kA460P30ACCE0

400kA460P40ACCE0

500kA460P50ACCE0

Active Surge Monitor (ASM)

100kA460P10ACTG0

16 x 16 x 8 in.NEMA 4 enclosure(steel)

200kA460P20ACTG0

300kA460P30ACTG0

400kA460P40ACTG0

600kA460P60ACTG0Internal Disconnect(#6 – 1/0)

Counter, Lights, Alarm, Contacts

100kA 460P10ARCE012 x 12 x 7 in.NEMA 1/12/3R/4(steel)

200kA460P20ARCE0

300kA 460P30ARCE0400kA

460P40ARCE0 16 x 14 x 7 in.NEMA 1/12/3R/4(steel)

500kA460P50ARCE0Through Door Disconnect

Active Surge Monitor (ASM)

100kA 460P10ATTG0

16 x 16 x 8 in.NEMA 4 enclosure(steel)

200kA460P20ATTG0

300kA 460P30ATTG0

400kA460P40ATTG0

600kA460P60ATTG0

SPLIT

2 Phases, 1 Neutral, 1 Ground

Phase B (Black)

Phase A (Black)Neutral (White)

V

V

}}

Ground (Green)

WYE

3 Phases, 1 Neutral, 1 Ground

}

Phase A (Black)Phase B (Black)

Neutral (White)

Phase C (Black)Ground (Green)

A

C

N

V

B

HIGH LEG DELTA

(B High) 3 Phases, (B High)1 Neutral, 1 Ground

Phase A (Black)Phase B (Orange)

Neutral (White)

Phase C (Black)

Ground (Green)

}V

SINGLE POLE

1 Phase, 1 Neutral,1 Ground

V}Neutral (White)

Phase A (Black)

Ground (Green)

DELTA & HRG WYE

3 Phases, 1 Ground

Phase A (Black)

Phase C (Black)

Phase B (Black)

Ground (Green)

}V

CORNER GROUNDDELTA

(B grounded)2 Phases, 1 Ground

Phase A (Black)Phase C (Black)

Ground (Green)

V}

VPR or MCOV with disconnect switch or ASM Monitoring option could vary. Contact the factory for details.

1 1200 VPR for L-N and L-G and 1800 VPR for L-L is with reference to the B Phase High Leg

Performance DataCommon Power Systems

UL 1449 Fourth Edition Test Data

Voltage Protection Ratings (VPR - 3kA)

In

SCCRMCOV

L-NL-G

N-GL-L

120S = 120/240V Split Phase (≤300kA)

700700

7001200

20kA100kA

150

120S = 120/240V Split Phase (>300kA)

800700

7001200

20kA100kA

150

120Y = 208Y/120V 3Ø Wye (≤300kA)

800700

7001200

20kA200kA

150

120Y = 208Y/120V 3Ø Wye (>300kA)

800700

7001200

20kA200kA

150

240H = 240/120V (B Ph High Leg Delta) (≤300kA) 800/12001700/12001

7001200/18001

20kA200kA

320/150

240D = 240V 3Ø Delta (≤300kA)

-1200

-1800

20kA200kA

320

277Y = 480Y/277V 3Ø Wye (≤300kA)

12001200

12002000

20kA200kA

320

277Y = 480Y/277V 3Ø Wye (>300kA)

12001000

12001800

20kA200kA

320

480D = 480V 3Ø Delta

-1800

-1800

20kA200kA

552

220Y = 380Y/220V 3Ø Wye (≤300kA)

12001200

12002000

20kA200kA

320

347Y = 600Y/347V 3Ø Wye

15001500

15002500

20kA200kA

420

600D = 600V Delta

-2500

-2500

20kA200kA

690

Voltage Code120/240V Split Phase, 1Ø, 3W + ground120S

208Y/120V Wye, 3Ø 4W + ground

120Y

240V Delta, 3Ø 3W + groundkA Available: 100, 200, 300 & 400

240D

380Y/220V Wye

220Y

240/120V Delta High Leg

240H

480Y/277V Wye, 3Ø 4W + ground

277Y

480V Delta, 3Ø 3W + groundkA Available: 100, 200, 300 & 400

480D

600Y/347V Wye

347Y

600V Delta 3Ø 3W + groundKA Available: 100 & 200

600D

Additional system voltages are available, please

contact factory.

Indicate UL Type 1 or 2

Choose Voltage Code

schneider-electric.us/surge

se.com/us/en/work/support/customer-care/ | 1-877-342-5173

@ Copyright October 2020. Publication DS-70127 RevY

Schneider Electric14550 58th St. North, Clearwater, FL 33760

Benefits: • UL 1449 Fourth Edition listed

• 100kA – 600kA per phase ratings

• Type 1: UL 1449 4th Edition, CSA 22.2 No. 269.1

• Type 2 (optional): UL 1449 4th Edition, CSA 22.2 No. 269.2, UL 1283

• 20kA Inominal (In)

• 200kA SCCRs (most models)

• Complies with UL 96A 12th Edition master label requirements for

lightning protection systems

• Voltage Specific Design – Highly configurable

• All MOV suppression elements monitored

• All Modes of Protection

• Optional Rotary Disconnect Switch

• 10-year limited warranty

Performance Specifications

Surge capacities L-N L-G N-G

100kA per phase 50kA 50kA 50kA






UL 1449 Fourth Edition listed type 1, CSA 22.2 No. 269.1

Optional UL 1449 Fourth Edition type 2 SPD, CSA 22.2 No. 269.2

UL 1449 Fourth Edition tested Inominal (In): 20kA

UL 1449 Fourth Edition tested SCCR: 200kA and 100kA (120/240V Split)

AC sinewave tracking filter with EMI/RFI filtering up to -50dB from 10kHz to

100MHz (type 2 option only, including UL 1283 listing)

Repetitive impulse: 5,000 hits

Less than 1 nanosecond response time

Physical Specifications

Relative humidity range: 0 - 95% non-condensing

Operating frequency: 47 - 63Hz

Operating temperature: -15° F (-25° C) to 140° F (+60° C)

Weight: 23 - 32 lbs. (10.4 - 14.5 kg.)

Standard NEMA 4 enclosure

Enclosure size: see table on back of page

Lug size: #2 - #10 AWG (with optional disconnect switch: #8 - #1/0)

Breaker Range: 30A – 100A (Breaker selection determined by size of

conductors feeding SPD per applicable codes & regulations)

Design Attributes

Designed, manufactured and tested consistent with:

– ANSI/IEEE C62.41.1-2002, C62.41.2-2002, C62.45-2002,

C62.62-2010, C62.72-2016, IEEE SA 1100-2005 (Emerald Book)

– Meets current NEC® Article revisions for installations

– UL 96A and NFPA 780 lightning protection

High energy parallel design for category C-high applications

For external mounting on electrical distribution equipment, switchgear,

switchboards, motor control centers, panelboards, transfer switches.

Individually fused and thermally protected MOVs

Replaceable module construction

Solid state bidirectional operation

Quality, Standards and Validation

Type 1: UL 1449 Fourth Edition, CSA 22.2 No. 269.1

Type 2 (optional): UL 1449 Fourth Edition, CSA 22.2 No. 269.2, UL 1283

UL file: VZCA.E321351 and VZCA.E324279 at www.UL.com

RoHS-compliant

Operational test performed before shipment

ISO 9001:2008 quality management system

ISO 17025:2005 laboratory qualification

Diagnostic Monitoring

100% monitoring – every MOV is monitored, including N-G

Green LED status indicator per phase

Red LED service indicator

Audible alarm with silence button

Test function: toggles red service LED, audible alarm and dry contact

N-G overvoltage detection

Phase monitoring (toggles LED and dry contacts)

Two sets of Form C dry contacts, 24V, 2A (ASM models have one set)

Surge counter, six-digit LCD, with test function, reset and

no-maintenance eprom memory

Available Active Surge Monitor (ASM), see pub. DS-70137 & SL-70109

400 SERIES

Model 460 (teXAS Series)Data Sheet

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Article 708 - Critical Operations Power Systems

In 2008, Article 708 - Critical Operations Power Systems (COPS) was added to the NEC in response to events such as terrorist attacks and hurricanes in the United States. Article 708.2 defines COPS as, “Power systems for facilities or parts of facilities that require continuous operation for the reasons of public safety, emergency management, national security or business continuity.” 8 Examples of facilities that utilize COPS include hospitals, data centers, police stations, 9-1-1 call centers, or critical portions of larger facilities. Important provisions for these facilities include:

– 708.20(D) - Surge Protective Devices, which states, “Surge protective devices shall be provided at all facility distribution voltage levels.” 9

– 708.14(4) - Wiring of HVAC, Fire Alarm, Security, Emergency Communications and Signaling Systems, which states, “Listed secondary protectors shall be provided at the terminals of the communication circuits.” 10

Installation of SPDs in a power system regulated by Article 708 must support the selective coordination practices applied to overcurrent devices, which must be specified by a professional engineer or other qualified person. Specific requirements are provided in Article 708.54.11

SUBSEQUENT NEC CHANGES

In October of 2014, the Fire Protection Research Foundation issued a document entitled, Data Assessment for Electrical Surge Protection Devices - Phase 1, Final Report.12 This report surveyed and summarized the impacts of transient overvoltages to electrical power distribution systems and equipment.

The findings influenced the development and adoption of new NEC Code articles requiring SPDs to be installed to protect the emergency power system of regulated facilities. The most important 2014 and 2017 NEC changes regarding SPDs include those in the following sections.

8 Ibid. p. 70-600.9 Ibid. p. 70-602.10 Ibid.11 Ibid. p. 70-604.12 Fire Protection Research Foundation, Data Assessment for Electrical Surge Protection Devices - Phase 1, Final Report. Quincy, Massachusetts, 2016

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Article 700

The provisions of Article 700 - Emergency Systems apply to

“… electrical safety emergency systems consisting of circuits and equipment intended to supply, distribute, and control electricity for illumination, power, or both, to required facilities when the normal electrical supply or system is interrupted.” 13

Circuits and equipment that provide illumination, ventilation, elevator, fire alarm, and fire pump functions to allow occupants to safely exit a building are all examples of Emergency Systems under Article 700. Within the section, Article 700.8 - Surge Protection requires that a listed SPD be installed in or on the switchboards and panelboards of all emergency systems to protect equipment from hazards associated with transient overvoltages.14 The article does not further specify the characteristics of SPDs that should be used.

Because Article 517 – Healthcare Facilities references Article 700, certain systems in healthcare facilities are impacted by Article 700 provisions. Article 517.26 states, “The life safety branch of the essential electrical system shall meet the requirements of Article 700, except as amended by Article 517.” 15 To understand the reference, it is important to understand how Article 517 defines the Life Safety Branch, which is shown in Figure 3 as part of a facility’s Essential Electrical System.

Figure 3: The Life Safety Branch is best understood in the context of the Essential Electrical System that Article 517 defines for healthcare facilities.

Non-EssentialSystem

EquipmentBranch

Essential Electrical System

ATS ATS ATS

NormalSource

EmergencySource

Life SafetyBranch

CriticalBranch

The NEC defines the Life Safety Branch as, “A system of feeders and branch circuits supplying power for lighting, receptacles, and equipment essential for life safety that is automatically connected to alternate power sources by one or more transfer switches during interruption of the normal power source.”16 Examples of equipment served by the Life Safety Branch include:

• illumination for egress• exit signage• alarm and alerting systems• communications systems• generator locations and generator accessories• elevators • automatic doors

Consequently, these systems must be protected by installing SPDs on the panelboards and switchboards that serve them.

13 National Fire Protection Association, NFPA 70 - National Electrical Code®, Fourteenth Edition, 2017. Quincy, Massachusetts, 2016. p. 70-581. 14 Ibid. p. 583. 15 Ibid. p. 423.16 Ibid. p. 70-419.

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OTHER IMPORTANT PROVISIONS

Article 620 - Elevators, Dumbwaiters, Escalators, Moving Walks, Platform Lifts, and Stairway Chairlifts

Article 620 sets for requirements elevators, dumbwaiters, escalators, moving walks, platform lifts, and stairway chairlifts, and was updated in the 2017 Edition. Within the section, Article 620.51 provides various requirements for the disconnecting means that must be provided for this equipment. It further states, “Where any of the disconnecting means in 620.51 has been designated as supplying an emergency system load, surge protection shall be provided.” 17

Article 645 - Critical Operations Data Systems

Article 645.2 defines a Critical Operations Data System as, “An information technology equipment system that requires continuous operation for reasons of public safety, emergency management, national security, or business continuity.” Article 645.18 requires surge protection for all such systems.18

Article 670 – Industrial Machinery

Article 670 addresses “the definition of, the nameplate data for, and the size and overcurrent protection of supply conductors to industrial machinery.” 19 Because electronic safety devices must be able to protect people from injury at all times, installing surge protection protect devices can protect equipment from surges to help ensure proper and safe operation. Article 670.6 thus requires that industrial machinery with electronic interlocks must have surge protection devices installed.

Article 695 – Fire Pumps

Other electronic safety devices that must work when needed include fire pumps that supply fire suppression systems. Article 695.15 states, “A listed surge protective device shall be installed in or on the fire pump controller.” An ASCO Power Technologies Fire Pump Controller is shown in Figure 4.

SUMMARY

Triennial revisions to the NEC make it important to track the editions of the code that is in effect for a project location. The NEC articles referenced herein constitute the bulk of requirements regarding the location and use of SPD in power distribution system. A look-up table summarizing key SPD-related NEC requirements is provided as follows.

Key 2017 NEC Surge Protection ProvisionsArticle Application Requirements

285 Surge Protective Devices 285.4, 285.6, 285.12, 285.3, 285.7

517 Healthcare Facilities 517.2, 517.26

620 Elevators/Escalators 620.51

645 IT/Data Systems 645.18

670 Industrial Machinery 670.6

695 Fire Pumps 695.15

700 Emergency Systems 700.1, 700.8

708 Critical Operations Power Systems 708.2, 708.10(D), 708.14(4)

Figure 4: Providing SPDs on fire pump controllers helps ensure reliable operation

during an emergency event.

17 Ibid. p 70-508.18 Ibid. p. 70-528.19 Ibid. p. 540.

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national electrical code (nec) 2017 requirements for surge

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