Download Generators 700 701 Systems

Catching up with Code:
Updates from
Generators, 700 & 701 Systems
Overview
May 3rd, 2017
gpm
NCEC ARTICLE 445
445.10 Suitable for the location
445.11 Suitable nameplate
445.12 (A) protected from overload (UL2200 = inherent
protection)
445.13 conductor ampacity of 115% of the genset output,
neutral per 220.61, groundfault current per 250.30A
445.18 Lockable Disconnect Means required (except portable
plug and cord, driving means shutdown, parallel operation)
445.20 GFCI rules for 15KW or smaller portable units
110.22 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.
110.26 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.
 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 225.30 Number of Supplies. ONE, then A2,3,4 for EM, LRS, OS
225.31 Disconnecting Means. Means shall be provided for disconnecting all
ungrounded conductors that supply or pass through the building or structure.
225.32 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 230.6 shall be utilized.
225.36 Type. The disconnecting means specified in 225.31 shall be
comprised of a circuit breaker, molded case switch, general-use
switch, snap switch, or other approved means. Where applied in
accordance with 250.32(B), Exception No. 1, the disconnecting
means shall be suitable for use as service equipment.
225.37 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)
240.21 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
240.21(A) through (H). Conductors supplied under the provisions of
240.21(A) through (H) shall not supply another conductor except
through an overcurrent protective device meeting the requirements
of 240.4.
240.21 (G) Conductors from Generator Terminals.
Conductors from generator terminals that meet the size requirement
in 445.13 shall be permitted to be protected against overload by the
generator overload protective device(s) required by 445.12.
240.24 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 240.24(B)(1) and (B)(2).
C, D, E and F apply as well.
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.
250.20 Alternating-Current Systems to Be Grounded. Alternatingcurrent systems shall be grounded as provided for in 250.20(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.
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
250.102 C 1. Use the
largest required of the
two.
250.30 Grounding Separately Derived Alternating-Current
Systems.
In addition to complying with 250.30(A) for grounded
systems, or as provided in 250.30(B) for ungrounded
systems, separately derived systems shall comply with
250.20, 250.21, 250.22, or 250.26, as applicable. Multiple
separately derived systems that are connected in parallel
shall be installed in accordance with 250.30.
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.
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 415.8.10.1
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
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 700.3 are met.
A portable or temporary alternate source shall be available whenever the
emergency generator is out of service for major maintenance or repair.
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.
700.5 C
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.
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.
700.8 Surge Protection. A listed SPD shall be installed in or on all emergency
systems switchboards and panelboards.
700.10 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 700.10(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…
700.10 B 5
Wiring
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.
700.10 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
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 700.10(D)(1).
 700.12 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.
Equipment for sources of power as described in 700.12(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.
700.12 Outdoor Generator Sets. Where an outdoor housed generator set is
equipped with a readily accessible disconnecting means in accordance with
445.18, 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 225.36.
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 700.26 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.
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.
•
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
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
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 909.20.6.1 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
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:
1.
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.
2.
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.
3.
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.
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.
701.7 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.
701.10 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.
701.12 B 5, Disconnects
Where an outdoor housed generator set is equipped with a readily accessible
disconnecting means in accordance with 445.18, 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 225.36.
Overcurrent Protection
Shall be accessible to only qualified individuals
Overcurrent devices must be selectively coordinated
through the system
CE Main page
www.meckpermit.com
Electrical page
http://charmeck.org/mecklenburg/county/LUESA/CodeEnforcement/In
spections/trades/Electrical/Pages/default.aspx
Selective OCP
http://charmeck.org/mecklenburg/county/LUESA/CodeEnforcement/In
spections/trades/Electrical/Documents/Selective%20OCP%20Coordina
tion.pdf
Electrical Consistency Page
http://charmeck.org/mecklenburg/county/LUESA/CodeEnforcement/Li
nks/Pages/Consistency.aspx
Review of Handouts
for
Codes and Standards Comparisons for Emergency and LR Standby
Systems
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 28208
980-314-3098
[email protected]