1. Catching up with Code: Updates from
Generators, 700 & 701 Systems Overview
May 3rd, 2017
gpm

2. NCEC ARTICLE 445 445.10 Suitable for the location
Suitable nameplate
(A) protected from overload (UL2200 = inherent protection)
conductor ampacity of 115% of the genset output, neutral per , groundfault current per A
Lockable Disconnect Means required (except portable plug and cord, driving means shutdown, parallel operation)
GFCI rules for 15KW or smaller portable units

3. 110. 22 Identification of Disconnecting Means
Identification of Disconnecting Means. Each disconnecting means shall be legibly marked to indicate its purpose unless located and arranged so the purpose is evident. The marking shall be of sufficient durability to withstand the environment involved.
Spaces About Electrical Equipment. Sufficient access and working space shall be provided and maintained about all electrical equipment to permit ready and safe operation and maintenance of such equipment.
The calculations of load on the genset shall be made in accordance with Article 220 (feeder) or by another approved method.

4. 225.1 Scope. This article covers requirements for outside branch circuits and feeders run on or between buildings, structures, or poles on the premises; and electrical equipment and wiring for the supply of utilization equipment that is located on or attached to the outside of buildings, structures, or poles.
See Number of Supplies. ONE, then A2,3,4 for EM, LRS, OS
Disconnecting Means. Means shall be provided for disconnecting all ungrounded conductors that supply or pass through the building or structure.
Location. The disconnecting means shall be installed either inside or outside of the building or structure served or where the conductors pass through the building or structure. The disconnecting means shall be at a readily accessible location nearest the point of entrance of the conductors. For the purposes of this section, the requirements in shall be utilized.

5. 225. 36 Type. The disconnecting means specified in 225
Type. The disconnecting means specified in shall be comprised of a circuit breaker, molded case switch, general-use switch, snap switch, or other approved means. Where applied in accordance with (B), Exception No. 1, the disconnecting means shall be suitable for use as service equipment.
Identification. Where a building or structure has any combination of feeders, branch circuits, or services passing through it or supplying it, a permanent plaque or directory shall be installed at each feeder and branch-circuit disconnect location denoting all other services, feeders, or branch circuits supplying that building or structure or passing through that building or structure and the area served by each.
(Excp. for residential and large capacity industrial)

6. Location in Circuit. Overcurrent protection shall be provided in each ungrounded circuit conductor and shall be located at the point where the conductors receive their supply except as specified in (A) through (H). Conductors supplied under the provisions of (A) through (H) shall not supply another conductor except through an overcurrent protective device meeting the requirements of
(G) Conductors from Generator Terminals. Conductors from generator terminals that meet the size requirement in shall be permitted to be protected against overload by the generator overload protective device(s) required by

7. 240. 24 Location in or on Premises. (A) Accessibility
Location in or on Premises. (A) Accessibility. Overcurrent devices shall be readily accessible and shall be installed so that the center of the grip of the operating handle of the switch or circuit breaker, when in its highest position, is not more than 2.0 m (6 ft 7 in.) above the floor or working platform
(B) Occupancy. Each occupant shall have ready access to all overcurrent devices protecting the conductors supplying that occupancy, unless otherwise permitted in (B)(1) and (B)(2).
C, D, E and F apply as well.

8. 250. 4 General Requirements for Grounding and Bonding
250.4 General Requirements for Grounding and Bonding. The following general requirements identify what grounding and bonding of electrical systems are required to accomplish. The prescriptive methods contained in Article 250 shall be followed to comply with the performance requirements of this section.
Alternating-Current Systems to Be Grounded. Alternating- current systems shall be grounded as provided for in (A), (B), (C), or (D). Other systems shall be permitted to be grounded. If such systems are grounded, they shall comply with the applicable provisions of this article.

9. The EGC shown in this slide for the top genset is not accurate if genset is running. The conductor would be a system bond jumper at this point. NEC C 1. Use the largest required of the two.

10. 250.30 Grounding Separately Derived Alternating-Current Systems.
In addition to complying with (A) for grounded systems, or as provided in (B) for ungrounded systems, separately derived systems shall comply with , , , or , as applicable. Multiple separately derived systems that are connected in parallel shall be installed in accordance with

11. Article 700 Emergency Systems
700.1 Scope. The provisions of this article apply to the electrical safety of the installation, operation, and maintenance of 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.
700.2 Emergency Systems. Those systems legally required and classed as emergency by municipal, state, federal, or other codes, or by any governmental agency having jurisdiction. These systems are intended to automatically supply illumination, power, or both, to designated areas and equipment in the event of failure of the normal supply or in the event of accident to elements of a system intended to supply, distribute, and control power and illumination essential for safety to human life.

12. Per NCBC the following are required to be on the Emergency System or Emergency power source (State Facilities have different requirements)
For Group A occupancies emergency voice/alarm communication systems
Exit signs
Means of Egress illumination
For Semiconductor fabrication facilities, see NCBC
For Highly toxic and toxic materials per NCBC 414
For Pyrophoric materials with silane gas
For High Rise; exit signs, means of egress illumination, elevator car lighting, emergency voice/alarm communication systems, automatic fire detection systems, fire alarm systems, electrically powered fire pumps
For Underground buildings; Emergency voice/alarm communication systems, Fire alarm systems, Automatic fire detection systems, Elevator car lighting
For Group I-3 Occupancies power operated sliding doors or power operated locks for swinging doors

13. 700.3 Initial and Periodic Testing of the system and maintenance is required.
700.4 Capacity
The emergency system equipment shall be suitable for the maximum available fault current at its terminals.
The alternate power source shall be permitted to supply emergency, legally required standby, and optional standby system loads where the source has adequate capacity or where automatic selective load pickup and load shedding is provided as needed to ensure adequate power to (1) the emergency circuits, (2) the legally required standby circuits, and (3) the optional standby circuits, in that order of priority. The alternate power source shall be permitted to be used for peak load shaving, provided these conditions are met. Peak load shaving operation shall be permitted for satisfying the test requirement of 700.3(B), provided all other conditions of are met.
A portable or temporary alternate source shall be available whenever the emergency generator is out of service for major maintenance or repair.

14. 700.5 Transfer Equipment
Transfer equipment, including automatic transfer switches, shall be
identified for emergency use
approved by the authority having jurisdiction
shall be designed and installed to prevent the inadvertent interconnection of normal and emergency sources of supply in any operation of the transfer equipment.
Transfer equipment and electric power production systems installed to permit operation in parallel with the normal source shall meet the requirements of Article 705.
Means shall be permitted to bypass and isolate the transfer equipment.
Switches shall be electrically operated and mechanically held.
Transfer equipment shall supply only emergency loads.

15. 700.5 C

17. 700.6 Signals. Audible and visual signal devices shall be provided, where practicable, for the purpose described in 700.6(A) through (D). (A) Derangement. To indicate derangement of the emergency source. (B) Carrying Load. To indicate that the battery is carrying load. (C) Not Functioning. To indicate that the battery charger is not functioning. (D) Ground Fault. To indicate a ground fault in solidly grounded wye emergency systems of more than 150 volts to ground and circuit-protective devices rated 1000 amperes or more. The sensor for the ground-fault signal devices shall be located at, or ahead of, the main system disconnecting means for the emergency source, and the maximum setting of the signal devices shall be for a ground-fault current of 1200 amperes. Instructions on the course of action to be taken in event of indicated ground fault shall be located at or near the sensor location.

18. 700.7 Signs. A sign shall be placed at the service-entrance equipment, indicating type and location of on-site emergency power sources. Where removal of a grounding or bonding connection in normal power source equipment interrupts the grounding electrode conductor connection to the alternate power source(s) grounded conductor, a warning sign shall be installed at the normal power source equipment stating: WARNING SHOCK HAZARD EXISTS IF GROUNDING ELECTRODE CONDUCTOR OR BONDING JUMPER CONNECTION IN THIS EQUIPMENT IS REMOVED WHILE ALTERNATE SOURCE(S) IS ENERGIZED.

19. Refer to Sections 700. 7(B) for emergency systems, 701
Refer to Sections 700.7(B) for emergency systems, 701.7(B) for legally required standby systems, and 702.7(B) optional standby systems for the requirements for these warning signs.
Make the point about the grounding location information that must also be provided on the warning sign.

20. 700.8 Surge Protection. A listed SPD shall be installed in or on all emergency systems switchboards and panelboards.
Wiring, Emergency System.
All boxes and enclosures (including transfer switches, generators, and power panels) for emergency circuits shall be permanently marked so they will be readily identified as a component of an emergency circuit or system.
Emergency loads shall be kept entirely independent of all other wiring and equipment, unless otherwise permitted in (B) (1) through (5)
1.Normal power in transfer equipment, 2. 2 sources in exit or egress lighting, 3. or its load control, 4. Common j box for unit equipment (br. crkt. and emerg. crkt. only), 5. wiring from an emergency source to supply emergency and other loads, where we can use separate switchboard or switchgear enclosures, seperate feeders, individual disconnects, etc…

21. B 5
Wiring

22. 700.10 Wiring, Emergency System
Emergency wiring circuits shall be designed and located so as to minimize the hazards that might cause failure due to flooding, fire, icing, vandalism, and other adverse conditions.
Fire Protection. Emergency systems shall meet the additional requirements in (D)(1) through (D)(3) in assembly occupancies for not less than 1000 persons or in buildings above 23 m (75 ft) in height.
D 1, Emergency System
Feeder-circuit wiring shall meet one of the following conditions: (1) Be installed in spaces or areas that are fully protected by an approved automatic fire suppression system (2) Be a listed electrical circuit protective system with a minimum 2-hour fire rating (3) Be protected by a listed thermal barrier system for electrical system components with a minimum 2-hour fire rating (4) Be protected by a listed fire-rated assembly that has a minimum fire rating of 2 hours and contains only emergency wiring circuits (5) Be encased in a minimum of 50 mm (2 in.) of concrete

23. D2, Feeder-Circuit Equipment
D2, Feeder-Circuit Equipment. Equipment for feeder circuits(including transfer switches, transformers, and panelboards) shall be located either in spaces fully protected by approved automatic fire suppression systems (including sprinklers, carbon dioxide systems) or in spaces with a 2-hour fire resistance rating.
D3, Generator Control Wiring. Control conductors installed between the transfer equipment and the emergency generator shall be kept entirely independent of all other wiring and shall meet the conditions of (D)(1).
General Requirements
Current supply shall be such that, in the event of failure of the normal supply to, or within, the building or group of buildings concerned, emergency lighting, emergency power, or both shall be available within the time required for the application but not to exceed 10 seconds.
Equipment shall be designed and located so as to minimize the hazards that might cause complete failure due to flooding, fires, icing, and vandalism.

24. Equipment for sources of power as described in 700
Equipment for sources of power as described in (A) through (E) where located within assembly occupancies for greater than 1000 persons or in buildings above 23 m (75 ft) in height with any of the following occupancy classes — assembly, educational, residential, detention and correctional, business, and mercantile—shall be installed either in spaces fully protected by approved automatic fire suppression systems (sprinklers, carbon dioxide systems, and so forth) or in spaces with a 1-hour fire rating. (2 hr. per NCBC)
Where power is required for the operation of dampers used to ventilate the generator set, the dampers shall be connected to the emergency system.
Outdoor Generator Sets. Where an outdoor housed generator set is equipped with a readily accessible disconnecting means in accordance with , and the disconnecting means is located within sight of the building or structure supplied, an additional disconnecting means shall not be required where ungrounded conductors serve or pass through the building or structure.
Where the generator supply conductors terminate at a disconnecting means in or on a building or structure, the disconnecting means shall meet the requirements of

25. Exception: For installations under single management, where conditions of maintenance and supervision ensure that only qualified persons will monitor and service the installation and where documented safe switching procedures are established and maintained for disconnection, the generator set disconnecting means shall not be required to be located within sight of the building or structure served.
Overcurrent Protection Accessibility. The branch-circuit overcurrent devices in emergency circuits shall be accessible to authorized persons only.
Ground-Fault Protection of Equipment. The alternate source for emergency systems (genset) shall not be required to have ground-fault protection of equipment with automatic disconnecting means. Ground-fault indication of the emergency source shall be provided in accordance with 700.6(D) if ground-fault protection of equipment with automatic disconnecting means is not provided.
Selective Coordination. Emergency system(s) overcurrent devices shall be selectively coordinated with all supply-side overcurrent protective devices.

26. NFPA 110
The EPS shall be installed in a separate room for Level 1 installations. EPSS equipment shall be permitted to be installed in this room. The room shall have a minimum 2-hour fire rating or be located in an adequate enclosure located outside the building capable of resisting the entrance of snow or rain at a maxi­ mum wind velocity required by local building codes. No other equipment, including architectural appur­tenances, except those that serve this space, shall be permitted in this room.
Level 1 EPSS equipment shall not be installed in the same room with the normal service equipment, where the service equipment is rated over 150 volts to ground and equal to or greater than 1000 amperes.
The EPS equipment shall be installed in a location that permits ready accessibility and a minimum of 0.9 m (36 in.) from the skid rails' outermost point in the direction of access for inspection, repair, maintenance, cleaning, or replacement. This requirement shall not apply to units in outdoor housings.

27. 110 continued
The Level 1 or Level 2 EPS equipment location(s) shall be provided with battery-powered emergency lighting. This requirement shall not apply to units located outdoors in enclosures that do not include walk-in access. The emergency lighting charging system and the normal service room lighting shall be supplied from the load side of the transfer switch. The intensity of illumination in the separate building or room housing the EPS equipment for Level 1 shall be 32.3 lux (3.0 ft-candles).
110 also provides Mechanical requirements for genset ventilation

28. 701 SYSTEMS. Legally Required Standby
701.1 The provisions of this article apply to the electrical safety of the installation, operation, and maintenance of legally required standby systems consisting of circuits and equipment intended to supply, distribute, and control electricity to required facilities for illumination or power, or both, when the normal electrical supply or system is interrupted. The systems covered by this article consist only of those that are permanently installed in their entirety, including the power source.
701.2 Those systems required and so classed as legally required standby by municipal, state, federal, or other codes or by any governmental agency having jurisdiction. These systems are intended to automatically supply power to selected loads in the event of failure of the normal source

29. Per NCBC the following are required to be on the Legally Required Standby System (State Facilities have different requirements)
Smoke control system
Elevator power
Accessible Means of Egress lifts and sliding doors
Membrane Structure Auxiliary Inflation
For Occupancies with Hazardous Materials requiring Ventilation
For Occupancies with silane gas
For Covered Malls, exceeding 50,000 sf, voice/alarm communications
For High Rise; fire command center power and lighting, ventilation for smoke proof enclosures, elevator power (see of NCBC)
For Underground Buildings; Smoke Control System, Ventilation for smoke proof enclosures, fire pumps, elevators
Where required or provided for Elevator power
Smoke proof Enclosure ventilation

30. NCBC 909.20.6.1 (protection required comparable to fire pump in NFPA 70)
Ventilation systems. Smokeproof enclosure ventilation systems shall be independent of other build­ ing ventilation systems. The equipment, control wiring, power wiring and ductwork shall comply with one of the following:
Equipment, control wiring, power wiring and ductwork shall be located exterior to the building and directly connected to the smokeproof enclosure or connected to the smokeproof enclosure by ductwork enclosed by not less than 2-hour fire barriers constructed in accordance with Section 707 or horizontal assemblies constructed in accordance with Section 712, or both.
Equipment, control wiring, power wiring and ductwork shall be located within the smokeproof enclosure with intake or exhaust directly from and to the outside or through ductwork enclosed by not less than 2-hour fire barriers constructed in accordance with Section 707 or horizontal assemblies constructed in accordance with Section 712, or both.
Equipment, control wiring, power wiring and ductwork shall belocated within the building if separated from the remainder of the building, including other mechanical equipment, by not less than 2-hour fire barriers constructed in accordance with Section 707 or horizontal assemblies constructed in accordance with Section 712, or both.
Exceptions:
1. Control wiring and power wiring utilizing a 2-hour rated cable or cable system.
2. Where encased with not less than 2 inches (51 mm) of concrete.

31. 701.3 Initial and Periodic Testing of the system and maintenance is required.
701.4 The system is allowed to supply Optional Standby loads as long as it is capable of the load or can shed the optional load to meet requirements of the full required loads. System equipment must be rated for the available fault current.
701.5 Transfer equipment, shall be automatic, identified for standby use, approved by the authority having jurisdiction.
Means to bypass and isolate the transfer switch equipment shall be permitted. Where bypass isolation switches are used, inadvertent parallel operation shall be avoided.
Automatic Transfer Switches. Automatic transfer switches shall be electrically operated and mechanically held.

32. A) Signage shall be placed at the service indicating the type and location of the Standby Source. B) A warning sign shall be placed as applicable for grounding/bonding hazards.
The Legally Required Standby System wiring shall be permitted to occupy the same raceways, cables, boxes, and cabinets with other general wiring. This makes it less reliable than the isolated Emergency System.
B 5, Disconnects
Where an outdoor housed generator set is equipped with a readily accessible disconnecting means in accordance with , and the disconnecting means is located within sight of the building or structure supplied, an additional disconnecting means shall not be required where ungrounded conductors serve or pass through the building or structure.
Where the generator supply conductors terminate at a disconnecting means in or on a building or structure, the disconnecting means shall meet the requirements of

33. Overcurrent Protection
Shall be accessible to only qualified individuals
Overcurrent devices must be selectively coordinated through the system

34. Electrical Consistency Page
CE Main page
Electrical page
Selective OCP
Electrical Consistency Page

35. Codes and Standards Comparisons for Emergency and LR Standby Systems
Review of Handouts
for
Codes and Standards Comparisons for Emergency and LR Standby Systems

36. Thank you for your partnership to build a safe and thriving community!
Gary Mullis, Electrical Code Administrator
Mecklenburg County Code Enforcement
2145 Suttle Ave., Charlotte, NC