Wires: Single insulated conductors No. 8 AWG gauge or smaller.
In the English system, the B&S Gauge or Browne and Sharpe Gauge is used.
The smallest size is No. 14.
Conductor sizes from No. 18 (AWG 1) to No. 10 (AWG No. 0000) are expressed in AWG.
Cables: Single insulated conductors No. 6 AWG or larger.
May be several conductors of any size assembled into a single unit.
Bus Bars: Large conductors that are not circular in cross-section and are typically used to supply main switchboards.
Wires and cables can be solid or stranded.
Stranded Wire: A group of wires twisted together to form a metallic string.
Cord: Insulated stranded wire, such as the cord of a flat iron.
MCM (Thousand Circular Mils):
Used to designate conductors beyond AWG No. 4/0.
Smallest MCM size: 250 MCM (1/2" diameter).
Largest MCM size: 500 MCM.
Circular Mil: An artificial area measurement representing the square of the cable diameter when the diameter is expressed in mils (thousandths of an inch).
Example: A solid conductor 1/2" in diameter is 500 mils in diameter, or 250,000 circular mils in area, represented as (500)2 or 250 MCM.
In metric, wire sizes are expressed as the cross-sectional area of the conductor in units of square millimeters (sq. mm.).
Metric equivalent of AWG No. 14 is 2.0 sq. mm.
Types of Cables
Armored Cable
Mineral Insulated Cable
Non-metallic Sheathed Cable
Coaxial Cable
Shielded Cable
Cable Descriptions
Armored Cable:
Electrical cable consisting of two or more insulated conductors protected by a flexible, helically wound metal wrapping.
Most common type of AC run without raceways.
NEC type flexible; trade name is BX Cable.
Mineral Insulated Cable:
Electrical cable consisting of a tubular copper sheath containing one or more conductors embedded in a highly compressed, insulating refractory mineral.
Non-metallic Sheathed Cable:
Electrical cable consisting of two or more insulated conductors enclosed in a nonmetallic, moisture-resistant, flame-retardant sheath.
Also called Romex.
Coaxial Cable:
A cable for transmitting high-frequency telephone, digital, or television signals.
Consists of an insulated conducting tube enclosing an insulated conducting core.
Shielded Cable:
An electric cable enclosed in a metallic sheath in order to reduce the effects of external magnetic fields.
Thermoplastic Cable Types
Type Letter T: Thermoplastic.
Maximum operating temperature: 60°C or 140°F.
Type Letter TW: Moisture Resistant Thermoplastic.
Can be used above or below ground.
Maximum operating temperature: 60°C or 140°F.
Type Letter THW: Moisture and Heat Resistant Thermoplastic.
Can be used above or below ground.
Maximum operating temperature: 75°C or 167°F.
Type Letter THHN: Heat-resistant Thermoplastic.
Above ground only.
Maximum operating temperature: 90°C or 194°F.
Type Letter THWN: Moisture and Heat Resistant Thermoplastic.
Above ground only.
Maximum operating temperature: 75°C or 167°F.
Type Letter RHW: Moisture and Heat Resistant Rubber.
Maximum operating temperature: 75°C or 167°F.
Type Letter SA: Silicone-Asbestos.
Maximum operating temperature: 90°C or 194°F.
Type Letter AVA: Asbestos and Varnished Cambric.
Maximum operating temperature: 110°C or 230°F.
Type Letter XHHW: Moisture and heat resistant cross-linked thermosetting polyethylene.
Maximum operating temperature: 90°C or 194°F for dry locations; 75°C or 167°F for wet locations.
Conductor Current Carrying Capacity (Ampacity)
Maximum operating temperature that its insulation can withstand continuously.
Heat is generated due to current flow and conductor resistance.
Conductors in enclosed conduits dissipate heat less easily than those in free air, so their current rating is lower.
Conduits
Condulets: Fitting used with RSCs and IMCs.
EMTs: Not threaded but use set screw and pressure fitting. Not recommended for embedding in concrete or permitted in hazardous areas.
IMCs: Yield a larger inside diameter for easier wire pulling and is lighter than RSC.
Conduits are circular raceways used to enclose wires and cables; made of metal or plastic.
Purposes of Conduits:
Protect enclosed conductors from mechanical injury and chemical damage.
Protect people from shock hazards by providing a grounded enclosure.
Provide a system ground path.
Protect surroundings against fire hazards from overheating or short-circuiting of conductors.
Electrical Metal Tubing (EMT), Thin-wall steel conduits
Raceways
Channels or wiring accessories used for holding wires, cables, and bus bars.
Do not pass through walls.
Can be made of metal, plastic, or any insulating medium.
Types of Raceways:
Floor Raceways:
Underfloor raceways
Cellular metal floor raceways
Cellular concrete floor raceways (precast)
Ceiling Raceways:
Header ducts (wireways)
Distribution ducts (laterals)
Outlets and Receptacles
Outlet: A point in the wiring system where current is taken to supply utilization equipment. Refers to the entire box assembly.
Receptacle: The wiring device in which the utilization equipment (appliance) cord is plugged into.
Kinds of Outlets:
Convenience Outlet or Attachment Cap: The complete set-up which establishes a connection between the conductor of the flexible cord and the conductors connected permanently to the receptacle; the common wall outlet.
Lighting Outlet: An outlet intended for direct connection to a lamp holder, lighting fixture, or pendant cord terminating in a lamp holder.
Receptacle Outlet
Switches
Devices for making, breaking, or changing conditions in an electrical circuit under the conditions of load for which they are rated.
Rated according to current and voltage, duty, poles and throw, fusibility, and enclosure.
Ways Switches Can be Classified:
According to voltage
According to intensity of use
According to type of service
According to type of operation mechanism
Switches Classified by Intensity of Use:
Normal Duty (ND): Intended for normal use in light and power circuits as in general-purpose switches.
Heavy Duty (HD): Intended for frequent interrupting.
Light Duty (LD): Intended to connect the loads occasionally, such as service switches.
Switches Classified by Type of Service:
Service Switch: Intended to disconnect all the electric service in the building except emergency equipment. This may comprise one to six properly rated switches that are assembled into a switchboard.
Types of Power Switches:
General Purpose Switches: Intended for use in general distribution and branch circuits.
Disconnecting or Isolating Switches: Intended for disconnecting or isolating circuits; used for circuits rated at more than 600 volts.
Wiring Switches:
Includes all the relatively small switches employed in interior wiring installations for the control of branch circuits, individual lamps or appliances.
May either be the flush type, surface type, or the pendant type.
Kinds of Wiring Switches:
General-purpose switches: Single-pole or double-pole switches for the general purpose use of connecting or cutting-off circuits for the control of lamps or other loads from a single point.
Three-way switches: Used where it is desired to control lamps from two different points, as in a stairwell.
Four-way switches: Used in conjunction with two 3-wire switches where it is desired to control lamps from three or more desired points.
Electrolier or multi-circuit switches: Used for the control of lights in multi-lamp fixtures so that one lamp or set of lamps may be turned on alone or in combination with other lamps.
Momentary contact switches: Used where it is desired to connect or cut-off a circuit for only a short duration. The switch is provided with a spring so that it will return to its original position as soon as the handle or button is released.
Dimmer switches: A rheostat or similar device for regulating the intensity of an electric light without appreciably affecting spatial distribution. Also called DIMMER.
Switches According to Operation Mechanism:
Rotary Switch
Push-button Switch
Toggle or Tumbler Switch
Special Kinds of Switches:
Time Controlled Switches: This device comprises a precision low speed miniature driver motor (timer) to which some type of electric contact-making device is connected.
Air Switch: A switch in which the interruption of a circuit occurs in air.
Knife Switch: A form of air switch in which a hinged copper blade is placed between two contact clips.
Float Switch: A switch controlled by a conductor floating in a liquid; used to detect the level of liquid in a tank.
Mercury Switch: An especially quiet switch that opens and closes an electric circuit by shifting a sealed glass tube of mercury so as to uncover or cover the contacts; heavy equipment.
Key Switch: Switch operated only by inserting a key or a card; aka CARD SWITCH.
Automatic Transfer Switch (ATS): An essential part of an emergency or standby service, is basically a double throw switch, generally 3-pole, so arranged that on failure of normal power, emergency service is also automatically supplied.
Liquid Flow Switch: sprinkler system; fire alarm system
Wall Plates or Faceplates
Coverings for switches and wall outlets usually made of metal or of phenolic compound (Bakelite).
Available in single gang, two-gang, and three-gang configurations.
Over-Current Circuit Protective Devices
Devices whose sole purpose is to protect insulation, wiring, switches, and other apparatus from overheating or burning, due to overloads, to faults, or to short circuits, by automatically cutting off the circuit.
Types of Over-Current Protective Devices:
Fuse: An over-current protective device consisting of an alloy link of wire with a low melting temperature which is inserted in the circuit. Any dangerous current melts this fuse and opens the circuit.
Circuit Breakers: An over-current protective device designed to function as a switch. It can be manually tripped and breaks a circuit with an automatic tripping device without injury to itself. It is not self-destructive and can be reset after tripping. Most are equipped with both thermal and magnetic trips.
Panel Boards
Popularly known as PANEL or ELECTRIC PANEL.
The box wherein the protective devices are housed from which the circuits and busbars terminate.
If the devices are fuses, it is called a FUSE PANEL.
If the devices are circuit breakers, it is called a BREAKER PANEL.
It is rare that fuses and breakers are housed in the same box, except that a breaker panel may sometimes have a main switch and a fuse for overall protection of the panel.
Wiring Methods
Knob and Tube Wiring
Rigid Metal Conduit Wiring
Rigid Non-Metallic Conduit
Flexible Metal Conduit Wiring
Liquid-Tight Flexible Metal Conduit
Armored Cable Wiring (BX wiring)
Surface Metal Raceway Wiring
Flat Cable Assemblies
Lighting Track
Cable Tray-Open Raceway
Floor Raceways
Ceiling Raceway Systems
Pre-wired ceiling distribution Systems
Description of Wiring Methods:
Knob and Tube Wiring: An obsolete wiring system consisting of single insulated conductors secured to and supported on porcelain knobs and tubes. Wires running through walls are inserted into a nonmetallic fire-resistant tubing called a loom.
Rigid Metal Conduit Wiring: The best and most expensive among the usual type of wiring.
Advantages:
Fireproof
Moisture proof
Mechanically strong (resists nails and deformation)
Resists cement action when embedded in concrete or masonry
Lengths come in 10 ft (3M).
Rigid Non-Metallic Conduit: Made of materials such as fiber, asbestos-cement, soapstone, rigid PVC, and high-density polyethylene.
Lengths come in 10 ft (3M).
Flexible Metal Conduit Wiring: Installation is much easier and quicker than rigid metal conduits.
Lengths come in 25 ft to 250 ft (8M to 83M) depending on the size of the conduit.
Easily fixed with pipe straps or clamps; requires no elbow fittings.
Pull Boxes/ Connection or Outlet Boxes/Junction Boxes: Sheet metal boxes with knockout holes, providing access to conduits for installing wires and making connections.
Common Sizes:
4" square
4" octagonal boxes (for fixtures, junctions, and devices)
4" x 2 1/2" box where splicing is not required
Liquid-Tight Flexible Metal Conduit: Same construction as flexible conduit, but covered with a liquid-tight jacket; trade name SEALTITE.
Armored Cable Wiring (BX Wiring): Consists of rubber or thermoplastic covered wire protected by one or two layers of flexible steel armor.
Different from flexible metal conduit wiring in that the wires cannot be removed from the armor without destroying it.
Surface Metal Raceway Wiring: Wires are supported on a thin sheet steel casing; raceway is installed exposed, mounted on walls or ceiling; metal raceways must be continuous from outlet to outlet or junction box, designed especially for use with metal raceways.
Flat Cable Assemblies: A field installed rigidly mounted square structural channel (1 5/8" standard) designed to carry 2 to 4 conductors (No. 10 AWG) and will act as light duty (branch circuit) plug-in busways
Lighting Track: A factory-assembled channel with conductors for one to four circuits permanently installed in the track that will act as light duty (branch circuit) plug-in busways. It is the factory-assembled version of the flat cable assembly.
Cable Tray-Open Raceway: A continuous open support for approved cables; when used as a general wiring system, the cables must be self-protected, jacketed types, type TC.
Types of Floor Raceways (NEC):
Underfloor Ducts (UF): Installed beneath or flush with the floor, available in two basic designs.
Cellular Metal Floor Raceway: Commonly found in office landscaping, it is an integrated structural/electrical system in a cellular metal floor.
Precast Cellular Concrete: Made of concrete cells fed from header ducts, which are normally installed in concrete fill above the hollow core structural slab or fed from the ceiling void below. The cells can be used for air distribution and piping.
Ceiling Raceway Systems: Under-the-ceiling raceways composed of header ducts and distribution ducts separate for power and telephone cabling. They permit very rapid changes in layouts at low cost, particularly desirable in stores where frequent display transformations necessitate corresponding electrical facility adjustments.
Pre-wired Ceiling Distribution Systems: Ceiling raceways pre-wired in the factory and plugged in where required.
Types of Lamps
Filament Lamps
Gaseous Discharge Lamps
High-Intensity Discharge Lamps
Description of Lamp Types:
Filament Lamps:
Incandescent Lamp, R and PAR; Tungsten-Halogen.
Composed of a sealed glass containing a filament connected at its ends to the contact area in the base thereby completing an electric circuit
Gaseous Discharge Lamps:
Fluorescent Lamps; Energy Saving Lamps; Neon Vapor Lamps; PL Lamps.
High-intensity Discharge Lamps:
Mercury Vapor lamps, metal halide lamps, high pressure sodium lamps.
Members of the electric discharge family of light sources (as are fluorescent lamps).
Light is produced when a high-pressure electric arc is passed through a gas vapor, rather than by a low-pressure arc as in fluorescent lamps.
Illumination
Also known as ILLUMINAIRE.
The amount of light that falls on a surface; depends on the surface material being lit.
LUX: lumens/sq.m; Unit of light or luminous flux
Lumens: Unit of light or luminous flux
Foot candle: Unit of density of light; amount of lumens falling on an area one square foot one foot away
Lux: Unit of density of light; amount of lumens falling on an area one square meter one meter away; 1 foot candle = 10.76 lux
Candlepower (CP): Unit of light intensity
Footlambert (FL): Unit of brightness
Filament Lamps
Filament: Metal part of the Filament lamp
Incandescent lamp: Invented by Thomas Edison; inefficient, lots of power wasted instead of being turned into light.
Composed of a sealed glass containing a filament connected at its ends to the contact area in the base thereby completing an electric circuit.
Glass envelope comes in a variety of shapes and sizes; bulb designations consist of a letter to indicate its shape, and a number to indicate the diameter in eights of an inch.
R and PAR Lamps: Complete optical systems in a single bulb. The bulb contains a filament, reflector, and lens.
PAR stands for Parabolic Aluminized Reflector.
Tungsten Halogen Lamp: Also called QUARTZ or QUARTZ-IODINE; uses a halogen gas cycle to prevent rapid depreciation of the lamp filament and darkening of the transparent envelope; hot.
Fluorescent Lamps
Gaseous discharge lamp; no starter; no ballast.
Comprises a cylindrical glass tube, sealed at both ends and containing an inert gas (usually argon and mercury vapor).
Built into each end is a cathode which supplies the electrons to start and maintain the mercury arc or gaseous discharge; this light is absorbed by phosphors on the inside of the tube, which re-radiate the light in the visible light range.
Ballast: All fluorescent light sources require a control device or an auxiliary, called a ballast, located in the metal base.
Starter: For the operation of these lamps, an automatic switch known as a starter is required, in addition to the normal wall switch. The starter is self contained in a small tubular jacket which is inserted in the fixture body and is a replaceable part.
The ballast supplies the high voltage necessary to start the arc, and limits the current in the arc after it is formed.
Classifications of Fluorescent Lamps:
According to shape
According to method of tube operation
Kinds of Fluorescent lamps according to shape
Standard
Slimline
Circline
Slimline fluorescent lamps: does not require a starter; has single-pin bases, come in diameters 3/4", 1", and 1 1/2"; lengths of 42" to 96"
Kinds of fluorescent lamps according to method of tube operation
Pre-heat;
Instant Start
Rapid Start
Instant start: When the lamp is first switched on, a sufficient voltage is applied between the electrodes to strike the arc without preheating them. Instant-start lamps start as soon as current is turned on and eliminates the need for external starters. They have single-pin bases which are called "slim-line" lamps
Pre-heat fluorescent lamps: requires a starter which preheats the cathodes so that less voltage is required to strike an arc. There is a 2-5 seconds delay in the start of lamp after switch is on. This class is also called a SWITCH-START or STARTER START lamp. In certain cases, the starter can be eliminated by using a device called a TRIGGER-START BALLAST. This ballast provides both a current-limiting function and an appropriate automatic starting system.
Rapid Start: Are the most recent developments and the one that is most widely used. Rapid-start lamps use low-resistance electrodes which can be heated continuously with low current loses. These are the only fluorescent lamps that can be electrically dimmed or flashed. They start as quickly as the instant-start lamps; require no external starters; and the ballasts are smaller and more efficient.
Types of Light
Daylight: Average Efficiency (lumens/watt): 51; Used where color matching is important, equivalent to a north sky, not in general use because of high proportion of blue.
Cool White: Average Efficiency (lumens/watt): 58; Combines high efficiency with good color rendering; used in offices, schools; rather cold in appearance.
Deluxe Cool White: Average Efficiency (lumens/watt): 42; Less efficient than daylight by 20%; has better color rendering properties in the long wavelengths; used in stores and some factories where color is important.
White: Average Efficiency (lumens/watt): 59; Highest efficiency lamp; often used in factories and offices.
Warm White: Average Efficiency (lumens/watt): 59; High efficiency lamp; only moderate color rendering; poor with reds - emphasis is yellow and yellow greens; used in offices.
Deluxe Warm White: Average Efficiency (lumens/watt): 42; Most efficient lamp; closest approximation to tungsten filament color rendering; suitable for homes, restaurants, hotels.
High Pressure Sodium Lamps
Are the newest addition to the HID field. Its arc tube is made of high-density polycrystalline alumina and contains a mixture of primarily sodium.
Ballast
Auxiliary equipment for fluorescent and HID lamps which limits the amount of current in the lamp and provides the proper starting voltages. A power factor is frequently listed with each ballast description. The low power factor ballast is cheap and inefficient, while the high power factor ballast has a capacitor which improves its efficiency.
Mercury Vapor Lamps
High intensity discharge lamp;
Contains mercury vapor in a clear quartz arc tube, which when electrically excited, produces visible light of characteristically blue-green color;
Suitable only for limited industrial areas, general outdoor applications and street lighting.
Metal Halide Lamps
A modification of the mercury vapor with a narc of improved color. In addition to mercury, the arc tube contains metallic vapors such as indium iodide, thallium iodide, or sodium iodide; it possesses increased light output, improved color rendition without the use of phosphors, and small source size.
Classifications of Luminaires
Indirect;
Semi-indirect;
General diffuse or direct-indirect;
Semi-direct;
Direct
Types of Lighting
Cornice Lighting: A system where light sources are shielded by a panel parallel to the wall and attached to the ceiling to distribute light downwards over the wall. This is considered as direct lighting. Accentuates wall or display.
Cove Lighting: A system where light sources are shielded by a ledge to distribute light upwards over the ceiling and upper wall. It is a form of indirect lighting
Valance lighting: A system where light sources are shielded by a panel parallel to the wall usually across the top of a window. This provides light both upwards and downwards over the wall
Lighting Methods
Local Lighting;
General Lighting;
Combined Local and General Lighting (Localized Lighting)
Lighting Fixtures
Also known as LUMINARES (Lighting Fixtures).
The device which supports the source or sources of electric light and redirects or helps to control the light rays from the source; control of the rays is necessary to secure even distribution to avoid glare, to cut-off direct rays from polished surfaces.
Examples of Luminaires:
Ceiling Mounted Downlights
Spotlights
Pendants
Wall lights
Task and Table lights
Floor Lights
Fluorescent Fittings
Oddities
Exterior Lights
Classification of luminaires
Indirect: Downward Light %:
Direct: Downward Light %: >90; Upward Light %: <10. Characterized by high utilization of filters in work plane, high contrast with surroundings, sharp shadows, and direct and reflected glare
Semi-Direct: Downward Light %: 60-90; Upward Light %: 40-10. Eliminates high contrasts, brightening of upper portion makes room larger and pleasant; opening in upper part of luminaire allows for achieving action which greatly reduces dust and dust accumulation
General Diffusing: Downward Light %: 40-60; Upward Light %: 60-40. Distributes light equally in all directions; direct and reflected glare present; space pleasant
Semi-indirect: Downward Light %: 10-40; Upward Light %: 90-60. Provides good brightness control in the lower hemisphere and reasonable freedom from shadows
Foot Candles Required:
Casual Work (conferencing, interviewing, inactive filing): 10 to 30 FC
Moderate Work (intermittent filing, general clerical work): 30 to 50 FC
Prolonged Work (active filing, index referencing and mail sorting): 50 to 100 FC
Precision Work (accounting, auditing, tabulating, bookkeeping, business machine operation, reading poor reproductions, and rough layout drafting): 100 to 150 fc
Fine Precision Work (cartography, designing, detail drafting: 150 to 200 fc
Light Distribution Depends On:
Uniformity
Diffusion
Absence of Glare
Color of Light
Uniformity: Freedom from variations of illumination in a room or space. This signifies same intensity throughout and it is not always practicable to attain. A deviation of 25% from the average intensity cannot be detected by the eye, and is considered an acceptable maximum.
Diffusion: Refers to the number of directions and angles from which illuminating rays proceed. Good diffusion is obtained when light walls upon a matte or satin surface from a variety of directions thus eliminating shadows and streaks of brilliancy. When poor, it results from illumination from one direction only thus causing visual confusion because of distorted highlights and shadows.
Color of Light: Depends on the type of lamp chosen. Incandescent lamps provide yellow light, though there are many other colors depending on the color of their glass bulbs. Fluorescent lamps have the greatest variety of colors ranging from daylight to bluish white and even pinkish white. This is also used to enhance certain qualities. For example, de luxe FL lamps are used to enhance food in restaurants.
Absorption
In lighting; loss of light when light rays strike or traverse any medium.
Absorption Factor/Absorptance: The ratio of light absorbed by a material to the light falling upon it
Diffuse reflection: A beam of light is reflected diffusely, that is, its ray is scattered in all directions, if it strikes through a rough or matte surface
Specular reflection: A beam of light is specularly reflected when a light ray striking a shiny or glossy surface at an angle of incidence is reflected as the same beam with equal angle of reflection
Reflectance: Aka REFLECTION FACTOR; the ratio of light reflected by a surface to the light falling upon it
Transmission: The passage of light through a medium when light falls upon a transparent material. It is refracted (bent) as it passes through the material but emerges at the same angle that it entered
Diffused Transmission: When light passes through a translucent material (plastic, etc.), and the emerging rays are spread in all directions
Transmittance: Aka TRANSMISSION FACTOR; the ratio of light transmitted to light striking the surface
Lighting Terminology
Accent lighting: Directional lighting to emphasize a space or an object
Down Light: A fixture producing concentrated direct lighting from a single bulb; may be recessed in or mounted on the ceiling
High Hat: A term often applied to a can-type of recessed incandescent downlight
Eyeball: Recessed or semi-recessed lighting unit with a rotating spherical element that may be turned to project light in any direction
Lumiline: A tubular fluorescent lamp with a disc base at each end
Luminance Ceiling: A false ceiling of diffusing material with light sources mounted above
Filter: Device which changes either amount or color or both of light passing through it
Dimmer: A device to control the amount of light by reducing the voltage or the current; also called a RAYOSTAT
Capacitor: An electric component which consists of conducting plates insulated from each other by a layer of dielectric material; introduces capacitance into a circuit.
Capacitance: The quantitative measure of the electric-energy storage capability of a capacitor; usually measured in farads or microfarads
Columns
A rigid, relatively slender structural member; designed primarily to support axial, compressive loads; aka POST
Transmits compressive forces vertically along its shaft; If the load is centered, it will simply compress. If load is off center or applied laterally, the column will experience curvature (buckling).
Slenderness Ratio: The column's height-to-thickness ratio. The taller an object, the weaker it is.
Materials Used for Columns
Stone
Wood
Reinforced Concrete
Steel
Stone Columns
Columns that were used prior to the arrival of steel and concrete columns;
Dependent entirely on compressive forces;
Assembled by locking together one on top of another;
Stone columns aren't straight. ENTASIS
Wood Columns
Columns that may be solid, built up, or spaced;
Important things to consider when choosing material:
Lumber species;
Structural grade;
Modulus of elasticity;
Allowable compressive, bending and shear stress
Reinforced Concrete Columns
Tied Columns;
Spiral Columns;
Composite Columns;
Lally Columns
Tied columns: Reinforced concrete columns with longitudinal bars and lateral ties
Spiral Columns: Reinforced concrete columns with longitudinal bars and closely spaced continuous spiral hooping; requires a minimum of six vertical bars
Composite Columns: Reinforced concrete columns; structural steel column is embedded into the concrete core of a spiral column; structural steel is encased in concrete of at least 7 cm thick; steel carries the load; concrete needed for fireproofing so it is just a cover
Lally columns: Fabricated steel pipes provided with flat steel plates which holds a girder or girt; filled with grout or concrete to prevent corrosion. Steel pipes with concrete inside to prevent corrosion
Steel Columns
Columns of iron with low amounts of carbon; has carbon content less than that of cast iron and more than that of wrought iron; has qualities of strength, hardness and elasticity;
Usually pre-fabricated off-site and then assembled onsite, that results in relatively fast, precise construction of a structural frame; has high strength to weight ratio
Must be given protective coatings against fire
Latticed Columns: Made up of channels or angles connected by latticed bars; often used where light loads are to be supported on long columns
Built-Up Columns: Usually of H-shaped section formed by a combination of plates and angles
Battened Columns: Two component parts of the column are connected by batten plates; should be avoided if a continuous plate or latticing can be used instead
Other Terminology
Stikwel: A single component new generation of PVA glue; suitable for both hot press veneer and plywood/particle board lamination; also good for cold setting furniture assembly