Nfpa 231 pdf free download

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Standard for the Installation of Standpipes and Hose Systems. Tire facilities located within a structure shall adhere to the following requirements:. Standard on Explosion Prevention Systems. If you like d setup a quick demo, let us know at support madcad.

The mission of the international nonprofit NFPA, established inis to reduce the worldwide burden of fire and other hazards on the quality of life by providing and advocating consensus codes and standards, research, training, and education. That prevents vehicle parking or other means above it, and shall allow free. Standard by National Fire Protection Association,.

View all product details Most Recent. Nfpa Free Download Nfpa Pdf free. Any opinions expressed are the personal opinions of the author s , and do not necessarily represent the official position of the NFPA or its Technical Committees. In addition, the responses are neither intended, nor should be relied upon, to provide professional consultation or services. Do I need sprinklers in my building? It does not specify which buildings require a sprinkler system. The requirement to install a sprinkler system complying with NFPA 13 can usually be found in one of the following sources: building code; federal, state or local regulations; insurer's requirements; accreditation requirements; or owner's request.

Yes, both sections would be applied cumulatively to the design area chosen from Figure This is shown in the following example: The application area determined from Figure As required by Section Therefore, the original density chosen from Figure Ensure that there are no other design area modifications required for the system being installed 3. A point on the wiring system at which current is Location, Damp. Locations protected from weather and taken to supply utilization equipment.

An arrangement of incandescent lamps, subject to moderate degrees of moisture. Any current in excess of the rated current of basements, some barns, and some cold-storage warehouses. It may result Location, Dry. A location not normally subject to damp- from overload, short circuit, or ground fault. A location classified as dry may be tem- Informational Note: A current in excess of rating may be porarily subject to dampness or wetness, as in the case of a accommodated by certain equipment and conductors for a building under construction.

Therefore, the rules for overcurrent protection are specific for particular situations. Location, Wet. Installations underground or in concrete slabs or masonry in direct contact with the earth; in loca- Overcurrent Protective Device, Branch-Circuit.

A device tions subject to saturation with water or other liquids, such capable of providing protection for service, feeder, and branch as vehicle washing areas; and in unprotected locations ex- circuits and equipment over the full range of overcurrents be- posed to weather.

Such devices are provided with interrupting ratings appropriate for the in- Luminaire. A complete lighting unit consisting of a light tended use but no less than amperes. A de- power supply. It may also include parts to protect the light vice intended to provide limited overcurrent protection for source or the ballast or to distribute the light. A lampholder specific applications and utilization equipment such as lu- itself is not a luminaire. This limited protection is in addi- tion to the protection provided in the required branch cir- Motor Control Center.

An assembly of one or more en- cuit by the branch-circuit overcurrent protective device. Operation of equipment in excess of normal, full-load rating, or of a conductor in excess of rated ampac- Multioutlet Assembly. A type of surface, flush, or free- ity that, when it persists for a sufficient length of time, standing raceway designed to hold conductors and recep- would cause damage or dangerous overheating.

A fault, tacles, assembled in the field or at the factory. A single panel or group of panel units de- Raintight. Constructed or protected so that exposure to a signed for assembly in the form of a single panel, including beating rain will not result in the entrance of water under buses and automatic overcurrent devices, and equipped specified test conditions.

A receptacle is a contact device installed at the box placed in or against a wall, partition, or other support; outlet for the connection of an attachment plug. A single and accessible only from the front. A multiple receptacle is two or Photovoltaic PV System. The total components and sub- more contact devices on the same yoke. Receptacle Outlet. An outlet where one or more recep- tacles are installed. A compartment or chamber to which one or more air ducts are connected and that forms part of the air distri- Remote-Control Circuit.

Any electrical circuit that controls bution system. Retrofit Kit. A general term for a complete subassembly Power Outlet. An enclosed assembly that may include re- of parts and devices for field conversion of utilization ceptacles, circuit breakers, fuseholders, fused switches, equipment. Equipment enclosed in a case or vehicles, park trailers, or boats or to serve as a means for cabinet that is provided with a means of sealing or locking distributing power required to operate mobile or tempo- so that live parts cannot be made accessible without open- rarily installed equipment.

Premises Wiring System. Interior and exterior wiring, Informational Note: The equipment may or may not be including power, lighting, control, and signal circuit wiring operable without opening the enclosure. Separately Derived System. An electrical source, other This includes a wiring from the service point or power than a service, having no direct connection s to circuit source to the outlets or b wiring from and including the conductors of any other electrical source other than those power source to the outlets where there is no service point.

Such wiring does not include wiring internal to appli- Service. The conductors and equipment for delivering elec- ances, luminaires, motors, controllers, motor control cen- tric energy from the serving utility to the wiring system of ters, and similar equipment.

Informational Note: Power sources include, but are not Service Cable. Service conductors made up in the form of limited to, interconnected or stand-alone batteries, solar photovoltaic systems, other distributed generation systems, a cable.

Service Conductors. The conductors from the service point Qualified Person. One who has skills and knowledge re- to the service disconnecting means. The overhead conductors equipment and installations and has received safety training between the service point and the first point of connection to recognize and avoid the hazards involved. Service Conductors, Underground. The underground con- ductors between the service point and the first point of con- Raceway.

An enclosed channel of metallic or nonmetallic nection to the service-entrance conductors in a terminal box, materials designed expressly for holding wires, cables, or bus- meter, or other enclosure, inside or outside the building wall.

Informational Note: Where there is no terminal box, meter, Informational Note: A raceway is identified within specific or other enclosure, the point of connection is considered to article definitions. Constructed, protected, or treated so as to pre- vent rain from interfering with the successful operation of Service Drop.

The overhead conductors between the utility the apparatus under specified test conditions. Service-Entrance Conductors, Overhead System. The vents continued flow of follow current while remaining ca- service conductors between the terminals of the service pable of repeating these functions.

A protective device for drop or overhead service conductors. The necessary equipment, usually con- current device, including SPDs located at the branch panel. Service Lateral. The underground conductors between the utility electric supply system and the service point. Switch, Bypass Isolation.

A manually operated device used in conjunction with a transfer switch to provide a Service Point. The point of connection between the facili- means of directly connecting load conductors to a power ties of the serving utility and the premises wiring. Informational Note: The service point can be described as the point of demarcation between where the serving utility Switch, General-Use.

A switch intended for use in general ends and the premises wiring begins. The serving utility distribution and branch circuits. It is rated in amperes, and generally specifies the location of the service point based it is capable of interrupting its rated current at its rated on the conditions of service. Short-Circuit Current Rating. The prospective symmetri- Switch, General-Use Snap.

A form of general-use switch cal fault current at a nominal voltage to which an apparatus constructed so that it can be installed in device boxes or on or system is able to be connected without sustaining dam- box covers, or otherwise used in conjunction with wiring age exceeding defined acceptance criteria. Show Window. Any window used or designed to be used for the display of goods or advertising material, whether it Switch, Isolating.

A switch intended for isolating an elec- is fully or partly enclosed or entirely open at the rear and trical circuit from the source of power. It has no interrupt- whether or not it has a platform raised higher than the street ing rating, and it is intended to be operated only after the floor level.

Signaling Circuit. Any electrical circuit that energizes sig- Switch, Motor-Circuit. A switch rated in horsepower that naling equipment. The written consent of the authority switch at the rated voltage. Switch, Transfer. An automatic or nonautomatic device for Structure. That which is built or constructed. An enclosed assemblage of equipment e. A large single panel, frame, or assembly of transformers through which electric energy is passed for panels on which are mounted on the face, back, or both, the purpose of distribution, switching, or modifying its switches, overcurrent and other protective devices, buses, characteristics.

These assemblies are generally Surge Arrester. A protective device for limiting surge volt- accessible from the rear as well as from the front and are ages by discharging or bypassing surge current; it also pre- not intended to be installed in cabinets. An assembly completely enclosed on all sides Informational Note: Some systems, such as 3-phase and top with sheet metal except for ventilating openings 4-wire, single-phase 3-wire, and 3-wire direct current, may have various circuits of various voltages.

A nominal value assigned to a circuit or connections. The assembly may include control and auxil- system for the purpose of conveniently designating its volt- iary devices. Access to the interior of the enclosure is pro- age class e.

Switchgear rated below that permits satisfactory operation of equipment. Voltage to Ground. For grounded circuits, the voltage be- Thermal Protector as applied to motors.

A protective tween the given conductor and that point or conductor of device for assembly as an integral part of a motor or motor- the circuit that is grounded; for ungrounded circuits, the compressor that, when properly applied, protects the motor greatest voltage between the given conductor and any other against dangerous overheating due to overload and failure conductor of the circuit.

Constructed so that moisture will not enter the Informational Note: The thermal protector may consist of enclosure under specified test conditions. Constructed or protected so that exposure to the weather will not interfere with successful operation. Thermally Protected as applied to motors. The words Thermally Protected appearing on the nameplate of a motor Informational Note: Rainproof, raintight, or watertight or motor-compressor indicate that the motor is provided equipment can fulfill the requirements for weatherproof with a thermal protector.

Not connected to ground or to a conductive body that extends the ground connection. A power supply used to provide alternating current power to a load for some period Part II contains definitions applicable only to the articles of time in the event of a power failure. Informational Note: In addition, it may provide a more The definitions in Part I are intended to apply wherever constant voltage and frequency supply to the load, reducing the effects of voltage and frequency variations.

An inverter intended for use specifically covering installations and equipment operating in parallel with an electric utility to supply common loads at over volts, nominal. Electronically Actuated Fuse. An overcurrent protective Utilization Equipment.

Equipment that utilizes electric device that generally consists of a control module that pro- energy for electronic, electromechanical, chemical, heating, vides current sensing, electronically derived time—current lighting, or similar purposes.

Provided with a means to permit circulation of ing module that interrupts current when an overcurrent oc- air sufficient to remove an excess of heat, fumes, or vapors. Electronically actuated fuses may or may not operate Volatile Flammable Liquid.

Informational Note: A fuse comprises all the parts that Voltage of a circuit. The greatest root-mean-square rms form a unit capable of performing the prescribed functions. Controlled Vented Power Fuse. A fuse with provision for fuse link so that arc interruption by severing of the fuse controlling discharge circuit interruption such that no solid link or by opening of the contacts will occur under oil.

Oil Switch. A switch having contacts that operate under oil Informational Note: The fuse is designed so that dis- or askarel or other suitable liquid. A specific device or combina- path of the discharge or propagate a flashover to or between grounded members or conduction members in the path of tion of devices designed to bypass a regulator. Expulsion Fuse Unit Expulsion Fuse. A vented fuse unit in which the expulsion effect of gases produced by the arc ARTICLE and lining of the fuseholder, either alone or aided by a Requirements for Electrical Installations spring, extinguishes the arc.

Nonvented Power Fuse. A fuse without intentional provi- I. General sion for the escape of arc gases, liquids, or solid particles to the atmosphere during circuit interruption. This article covers general requirements for the examination and approval, installation and use, access to and Power Fuse Unit. A vented, nonvented, or controlled spaces about electrical conductors and equipment; enclosures vented fuse unit in which the arc is extinguished by being intended for personnel entry; and tunnel installations.

A fuse with provision for the escape tion regarding ADA accessibility design. The conductors and equipment required or permitted by this Code shall be acceptable only if approved. Multiple Fuse. An assembly of two or more single-pole fuses. Informational Note: See A device designed to close, open, or tion, and Use of Equipment. See definitions of Approved, both, one or more electrical circuits. Identified, Labeled, and Listed.

Circuit Breaker. A switching device capable of making, In judging equipment, considerations circuit conditions, such as those of short circuit. An assembly of a fuse support with either a fuse- 1 Suitability for installation and use in conformity with holder, fuse carrier, or disconnecting blade. The fuseholder the provisions of this Code or fuse carrier may include a conducting element fuse link or may act as the disconnecting blade by the inclusion of a Informational Note: Suitability of equipment use may be identified by a description marked on or provided with a nonfusible member.

A device, group of devices, or other cific purpose, environment, or application. Special condi- means whereby the conductors of a circuit can be discon- tions of use or other limitations and other pertinent infor- mation may be marked on the equipment, included in the nected from their source of supply.

Suitability of equipment may be tor. A mechanical switching device used for isolating a evidenced by listing or labeling. A switch capable of making, carrying, designed to enclose and protect other equipment, the and interrupting specified currents. A cutout in which all or 3 Wire-bending and connection space part of the fuse support and its fuse link or disconnecting 4 Electrical insulation blade is mounted in oil with complete immersion of the 5 Heating effects under normal conditions of use and also contacts and the fusible portion of the conducting element under abnormal conditions likely to arise in service.

This fault shall be assumed to be either be- 7 Classification by type, size, voltage, current capacity, tween two or more of the circuit conductors or between any and specific use circuit conductor and the equipment grounding conduc- 8 Other factors that contribute to the practical safeguard- tor s permitted in Listed equipment applied in ing of persons using or likely to come in contact with accordance with their listing shall be considered to meet the the equipment requirements of this section.

Unless identified for use in B Installation and Use. Listed or labeled equipment the operating environment, no conductors or equipment shall be installed and used in accordance with any instruc- shall be located in damp or wet locations; where exposed to tions included in the listing or labeling. Throughout this Code, the voltage consid- where exposed to excessive temperatures. The voltage rating of electrical equipment shall not be less than the Informational Note No.

Conductors normally used to carry cur- compounds can cause severe deterioration of many plastic materials used for insulating and structural applications in rent shall be of copper unless otherwise provided in this equipment. Where the conductor material is not specified, the material and the sizes given in this Code shall apply to Equipment not identified for outdoor use and equipment copper conductors.

Electrical equip- ment shall be installed in a neat and workmanlike manner. A Unused Openings. Unused openings, other than those Only wiring methods recognized intended for the operation of equipment, those intended for as suitable are included in this Code. The recognized meth- mounting purposes, or those permitted as part of the design ods of wiring shall be permitted to be installed in any type for listed equipment, shall be closed to afford protection of building or occupancy, except as otherwise provided in substantially equivalent to the wall of the equipment.

Equipment intended to inter- from the outer surface of the enclosure. Internal parts of electrical equipment, including busbars, Equipment intended to interrupt current at other than fault wiring terminals, insulators, and other surfaces, shall not be levels shall have an interrupting rating at nominal circuit volt- damaged or contaminated by foreign materials such as age sufficient for the current that must be interrupted.

There shall be no damaged parts that may adversely affect The overcurrent protec- such as parts that are broken; bent; cut; or deteriorated by tive devices, the total impedance, the equipment short- corrosion, chemical action, or overheating. Electrical equipment shall be firmly se- do so without extensive damage to the electrical equipment cured to the surface on which it is mounted.

Wooden plugs. B Cooling. Electrical equipment that depends on the C Temperature Limitations. The temperature rating as- natural circulation of air and convection principles for cool- sociated with the ampacity of a conductor shall be selected ing of exposed surfaces shall be installed so that room and coordinated so as not to exceed the lowest temperature airflow over such surfaces is not prevented by walls or by rating of any connected termination, conductor, or device. For equipment designed for Conductors with temperature ratings higher than specified floor mounting, clearance between top surfaces and adja- for terminations shall be permitted to be used for ampacity cent surfaces shall be provided to dissipate rising warm air.

Electrical equipment provided with ventilating openings shall be installed so that walls or other obstructions do not 1 Equipment Provisions. The determination of termination prevent the free circulation of air through the equipment.

Unless the equipment is listed and marked other- Because of different char- wise, conductor ampacities used in determining equipment ter- acteristics of dissimilar metals, devices such as pressure mination provisions shall be based on Table Informational Note: Many terminations and equipment are either marked with tightening torque or are identified as to b Termination provisions of equipment for circuits tightening torque in the installation instructions provided.

Connection by means of wire- up to their ampacity if the equipment is listed and iden- binding screws or studs and nuts that have upturned lugs or the equivalent shall be permitted for 10 AWG or smaller tified for use with such conductors conductors. Separately installed Terminals for more than one conductor and terminals pressure connectors shall be used with conductors at the used to connect aluminum shall be so identified. Conductors shall be spliced or joined with identified temperature rating of the connector.

Soldered C 2 , equipment markings or listing information may ad- splices shall first be spliced or joined so as to be mechani- ditionally restrict the sizing and temperature ratings of con- cally and electrically secure without solder and then be nected conductors. All splices and joints and the free ends of conduc- tors shall be covered with an insulation equivalent to that of On a 4-wire, delta-connected the conductors or with an identified insulating device.

Electrical equipment, 2 The label shall be permanently affixed to the equipment such as switchboards, switchgear, panelboards, industrial or wiring method and shall not be hand written. The marking shall meet the requirements in A General. Each disconnecting means shall be legibly marked to indicate its purpose unless located and arranged Informational Note No.

The marking shall be of sufficient of safety signs and labels for application to products. Equipment ordinary operation produce arcs, sparks, flames, or molten enclosures for circuit breakers or fuses applied in compli- metal shall be enclosed or separated and isolated from all ance with series combination ratings selected under engi- combustible material.

For motors, see Cir- Equipment en- operated in connection with electric railways. B Field-Applied Hazard Markings. Where caution, Unused current transform- warning, or danger signs or labels are required by this ers associated with potentially energized circuits shall be Code, the labels shall meet the following requirements: short-circuited.

Distances A Field Marking. Service equipment in other than shall be measured from the exposed live parts or from the dwelling units shall be legibly marked in the field with the enclosure or opening if the live parts are enclosed. The field marking s shall include the date the fault-current calculation was performed Table NFPA 70E, Stan- dard for Electrical Safety in the Workplace, provides 0— mm 3 ft mm 3 ft mm 3 ft assistance in determining the severity of potential exposure, — mm 3 ft 1.

Note: Where the conditions are as follows: Condition 1 — Exposed live parts on one side of the working space B Modifications.

When modifications to the electrical and no live or grounded parts on the other side of the working space, installation occur that affect the maximum available fault or exposed live parts on both sides of the working space that are current at the service, the maximum available fault current effectively guarded by insulating materials. Concrete, service equipment ratings are sufficient for the maximum brick, or tile walls shall be considered as grounded.

Condition 3 — Exposed live parts on both sides of the working The required field marking s in Working space shall not be Exception: The field marking requirements in Where rear access is required to work Where a discon- on nonelectrical parts on the back of enclosed equipment, a necting means is required to be lockable open elsewhere in minimum horizontal working space of mm 30 in.

The provisions for locking shall remain in place b Low Voltage. By special permission, smaller work- with or without the lock installed. In existing buildings where elec- trical equipment is being replaced, Condition 2 working clear- ance shall be permitted between dead-front switchboards, II.

Access and nance and supervision ensure that written procedures have working space shall be provided and maintained about all been adopted to prohibit equipment on both sides of the aisle electrical equipment to permit ready and safe operation and from being open at the same time and qualified persons who maintenance of such equipment. A Working Space.