Special occupancies and conditions — emergency, health care, classified locations

Chapter 7 — Special Conditions

Backup power, emergency systems, healthcare facilities, and communications. These articles cover edge-case rules examiners love.

10
Major Articles
15
Quiz Questions
20
Visual Examples
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700 — Emergency Systems

  • 700.3Emergency systems must be independent from normal supply. Transfer switches isolate sources to prevent backfeed.
  • 700.12Source of power must restore within 10 seconds of normal supply loss.
  • 700.10(D)Wiring for emergency circuits must be kept independent from other wiring systems.
  • 700.27Ground-fault protection: emergency feeders must maintain selective coordination.
  • 700.32Circuit wiring must be protected from physical damage — rigid raceways are common.
EXAM TRAP
10 SECOND RULE
Emergency power must come online in 10 seconds or less. Longer restore times belong to legally required standby (701).
Automatic transfer switch
Emergency ATS ensures independent supply.
Generator with quick-start system
Emergency generators must start fast.
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701 — Legally Required Standby

  • 701.2Serves loads that are legally mandated but not life safety (elevators, smoke control, heating in severe climates).
  • 701.11Transfer within 60 seconds — slower than emergency systems.
  • 701.10Circuit wiring kept separate like 700, but requirements are slightly less strict.
  • 701.12Selective coordination between feeders and OCPDs is required.
  • 701.17Identify legally required standby wiring separate from emergency and normal.
RULE OF THUMB
RULE — 60 SECONDS OR LESS
Not life safety, but still mandated ➜ restore within 1 minute.
Elevator on standby
Elevators commonly on 701.
Standby panel
Labeling distinguishes 701 wiring.
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702 — Optional Standby

  • 702.2Systems not required by law or code — convenience or business continuity.
  • 702.4Transfer equipment must prevent inadvertent interconnection with the normal source.
  • 702.7Service disconnect signage must indicate the type and location of optional standby power.
  • 702.5Can serve selected loads or entire premises.
  • 702.6Portable generators must be connected by listed transfer means — no 'suicide cords'.
NEC REFERENCE
OPTIONAL = CONVENIENCE
Optional standby is elective but still requires listed transfer equipment and safe isolation.
Generator inlet and interlock
Use listed inlets and interlocks.
Residential standby
Covers convenience or business continuity.
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708 — Critical Operations Power Systems (COPS)

  • 708.1Applies to facilities designated for national security, public health, or disaster recovery.
  • 708.20Requires a documented risk assessment and reliability strategy.
  • 708.52Protect wiring from fire/physical damage — 2-hour rated separations are common.
  • 708.54Mandatory maintenance and operational testing with records.
  • 708.22Highly reliable sources (dual utility, redundant generators, etc.).
TABLE
CRITICAL OPS QUICK HITS
RequirementNEC Section
Risk assessment708.20
2-hr rated separation708.52
Documented maintenance708.54
Redundant sources708.22
COPS exceeds 700/701 in rigor because of national/public importance.
Hardened utility room
Hardened infrastructure is typical.
Dual generators
Redundant supply for critical ops.
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517 — Health Care Facilities

  • 517.30Essential electrical systems split into life safety, critical, and equipment branches.
  • 517.34Each branch transfers via its own listed transfer switch(es).
  • 517.31Wiring separation — life safety branch kept independent.
  • 517.33Critical branch supplies patient care equipment.
  • 517.18Patient care spaces: strict grounding/receptacle rules.
CHART
HEALTHCARE BRANCHES
Branch TypeDescription
Life SafetyEgress, alarms, fire protection
CriticalPatient care & task loads
EquipmentBuilding services & mechanical systems
Three distinct branches — know what each serves.
Hospital panelboard
Clear separation for life safety branch.
OR receptacles
Critical branch powers patient care.
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720 — Circuits ≤50V

  • 720.1Covers certain low-voltage circuits (≤50V) not falling under 725/760/770.
  • 720.3Conductor sizes must still meet ampacity/insulation requirements.
  • 720.4Mechanical execution: neat, secure, and durable.
  • 720.5Protect from physical damage — low voltage ≠ no rules.
  • 720.6Grounding may still apply depending on the system.
JOBSITE HORROR STORY
JOBSITE HORROR — “IT’S ONLY 24 VOLTS”
A fire started from undersized thermostat wiring run through plenums without protection. Even ≤50V circuits must follow rules.
Low-voltage bundle
Class 2/3 and ≤50V still have rules.
Burnt thermostat cable
Improper low-voltage installs can fail dangerously.
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725 — Class 1, 2, and 3 Circuits

  • 725.2Class 1 can be up to 600V (power-limited designation possible). Class 2/3 are limited by source power.
  • 725.121Class 2/3 power supplies must be listed.
  • 725.136Maintain separation from power circuits or provide barriers.
  • 725.41Class 1 often treated like power circuits — same wiring methods.
  • 725.3Don't miss cross-references — other chapters can modify 725.
EXAM TRAP
CLASS 2 ≠ NO RULES
Limited power ≠ unlimited liberty. Use listed sources and maintain separation from power wiring.
Class 2 supply
Listed Class 2 sources are required.
Separated conductors
Keep power and Class 2/3 separated.
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750 — Energy Management Systems

  • 750.2Permanently installed systems that control electrical loads.
  • 750.10Must not override life safety systems (fire alarm, emergency lighting).
  • 750.20Disconnecting means required for EMS equipment.
  • 750.25Identify and protect control wiring as required.
  • 750.30Provide documentation for the AHJ on system operation.
RULE OF THUMB
RULE — EMS CAN’T OVERRIDE SAFETY
Shedding HVAC is fine; killing emergency lighting or fire alarm power is not.
EMS cabinet
EMS needs a disconnecting means.
Building automation
Often integrated with BAS.
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770 — Optical Fiber Cables

  • 770.24Mechanical execution still applies — fiber must be neat and secure.
  • 770.113Use fire-resistant cable types in risers/plenums.
  • 770.154Maintain separation from power conductors unless specifically permitted.
  • 770.21Use listed fiber raceways suitable for the application.
  • 770.2Applies whether fiber carries data or just light.
NEC REFERENCE
FIBER STILL COUNTS
Fiber isn’t conductive, but fire spread and separation rules still apply.
Fiber patch panel
Neat, secure installation is required.
Plenum-rated fiber
Use the right jacket in plenums/risers.
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760 — Fire Alarm Systems

  • 760.41(B)Fire alarm branch circuits: dedicated and identifiable; no other loads on the circuit.
  • 760.121/127Power-Limited Fire Alarm (PLFA) circuits use listed power supplies and cable types (FPL/FPLR/FPLP).
  • 760.136Maintain required separation from power conductors or use barriers/listed assemblies rated for co-routing.
  • 760.113 & 300.21Use proper cable rating for risers and plenums to limit smoke/fire spread.
  • NFPA 72 coord.Pathway survivability levels (e.g., 2-hour) for emergency voice/alarm systems are coordinated with NFPA 72.
TABLE
FIRE ALARM CABLE TYPES (PLFA)
CableWhere UsedNotes
FPLGeneral areasPower-limited fire alarm cable
FPLRRisersRiser-rated; not for plenums
FPLPPlenumsPlenum-rated; best flame/smoke
Pick the jacket rating to match the space. Keep FA circuits dedicated and identified.
Red fire alarm cable
Dedicated branch and listed PLFA cabling.
Fire alarm control panel
Coordinate survivability with NFPA 72.

Chapter 7 — Special Conditions: Quick Hits

700 Emergency

Life safety — power in 10 seconds.

701 Standby

Legally required — power in 60 seconds.

517 Healthcare

Life safety / critical / equipment branches.

708 COPS

National/public security — highest reliability.

702 Optional

Convenience standby — safe transfer only.

770 Fiber

Fire ratings and separation still required.

760 Fire Alarm

Dedicated circuits + FPL/FPLR/FPLP.

Knowledge Check

Answer all questions, then click Submit Answers. You’ll see your score after submitting. Nothing is graded until then.

1

A hospital's exit signs and fire alarm system lose power. What type of system must restore power within 10 seconds?

2

You're installing a generator for a data center that needs backup power for business continuity. What system type is this?

3

A fire station needs backup power for their communication equipment. What's the maximum transfer time allowed?

4

You're wiring a hospital operating room. Which branch supplies the patient monitoring equipment?

5

Emergency lighting circuits must be wired:

6

A 24V thermostat cable runs through a ceiling plenum. What fire rating is required?

7

You're installing a Class 2 power supply for a security camera system. What's required?

8

A fiber optic cable runs from the basement to the 10th floor. What rating is required?

9

An energy management system can control:

10

A hospital patient room needs receptacles. What's the minimum spacing requirement?

11

A generator transfer switch must prevent:

12

A data center needs the highest reliability power system. What type should be installed?

13

A 12V landscape lighting circuit is damaged and causing a fire. What went wrong?

14

A hospital's essential electrical system has how many branches?

15

A COPS facility requires: