Technical Information

Transcription

1 Technical Information

2 Basic Definition VOLT A measure of electrical pressure - The higher the potential difference the greater the pressure (flow) of electricity - Potiantial difference is the higher negative electrons over positive electrons. AMP A measurement of electrical flow - The rate at which the electricity passes through a conductor (wire). OHMS Measurement of resistance - The longer the conductor the greater the resistance - The wider the conductor the less resistance. HORSE POWER One horse lifting 100 pounds 5.5 feet in one second Equals 1HP - Lifting 100 lbs feet in one sec. = 2HP. WATT The amount of energy expanded by one amp of current at one volt of potential change. KILOWATT One thousand watts. TORQUE The form of mechanical energy generated by a rotating shaft or wheel (Waterwheel, windmill or electric motor). FT.-POUNDS OF TORQUE One FT. pound of torque is equivalent to one pound of force applied to a wheel one foot from the center of rotation. DC Direct Current - when the direction of current remains constant as in a battery. PULSATING DIRECT CURRENT Created by generators but pulsates with each rotation of the shaft. ARMATURE A coil of wire that rotates around a magnet.as it rotates current is induced into the wire. ALTERNATING CURRENT (AC) Current that charges direction with each 1/2 turn of the Armature - The natural product of rotating a wire loop with a magnetic field. CYCLE A matched pair of up & down curves reflecting one rotation of the armature. HERTZ One cycle per second. THREE PHASE SYSTEM The current in one coil will always be equal to the opposite of the current in the other two coils. Ohm s Law For Direct or Single Phase Non-Inductive Alternating Current Let: 1 = Ampere = unit of current strength or rate of flow. E = Volt = unit of electromotive force or electric pressure. R = Ohm = unit of resistance to flow of current. W = Watt = unit of power. Then: I = E E = IR R = E W = IE = E2 = 1 2 R R I R 1000W = 1 Kw or kilowatt; this is the usual unit of measure of electric power. 1 Kw hr. is the work done by one Kw in one hour. For alternating current circuits, the following rules are useful for finding the power of polyphase circuit. Let P.F. = Power Factor. Kw = Kw = Kw = 1.73 x E x I x P.F x E x I x P.F E x I x P.F (3-phase AC) (2-phase AC) (1-phase AC) 746 watts 1 HP = ft-lbs/min heat-units/hr., BTU 2.64 lbs. water evaporated 1 ft-lb - raising one pound one foot. 1 BTU (British Thermal Unit) = heat required to raise the temperature of one pound of pure water one degree Fahrenheit. Electrical Formula for Determining Amperes, Horsepower, Kilowatts and Kilovolt-Amperes Alternating Current Single Phase Two-Phase, 4 Wire Kilowatts I x E X P.F. I x E x 2 x P.F Kva I x E I x E x Horsepower Output I x E x %Eff. x P.F. I x E x 2 x %Eff. x P.F Amperes When HP is Known HP x 746 HP x 746 E x %Eff. x P.F. 2 x E x %Eff. P.F. Amperes When Kw is Known Kw x 1000 Kw x 1000 E x P.F. 2 x E x P.F. Amperes When Kva is Known Kva x 1000 Kva x 1000 E 2 x E 587

3 AC 3-Phase DC Kilowatts I x E x 1.73 x P.F. I x E Kva I x E x Horsepower Output I x E x 1.73%Eff. x P.F. I x E x 2 x %Eff Amperes When HP is Known HP x 746 HP x x E x %Eff. x P.F. E x %Eff. Amperes When Kw is Known Kw x 1000 Kw x x E x P.F. E Amperes When Kva is Known Kva x x E * In three-wire, two-phase circuits the current in the common conductor is 1.41 times that in either other conductor. Note: E=Volts; 1=Amperes; %Eff.=Percent Efficiency; P.F.=Power Factory. Equivalent Values In Different Units 746 watts.746 Kw ft-lbs/min. 550 ft-lbs/sec. 1 HP = 3545 heat-units/hr heat-units/min..707 heat-units/sec..175 lbs. carbon oxidized/hr lbs. water evaporated hr. from and at 212 F. 746 watts ft-lbs heat-units 1 HP kgm Hour =.175 lb. carbon oxidized with perfect efficiency 2.64 lbs. water evaporated from and at 212 F lbs. water raised from 62 to 212 F watts 1.34 HP ft-lbs/hr ft-lbs/min ft-lbs/sec. 1 Kw = 3412 heat-units/hr heat-units/min..948 heat-units/sec lb. carbon oxidized/hr lbs. water evaporated from and at 212 F. 8.9 heat-units/sq.ft/min. 1 Watt/ 6371 ft-lbs/sq. ft/min. Sq. In. =.193 HP/sq. ft ft. lbs HP hr. 1 Kg Kw hr. Meter =.0093 heat-units.283 Kw hr. 1 Lb..379 HP hr. Water heat-units Evap kgm from & at joules 212 F= ft-lbs lb. of carbon oxidized 1055 watt seconds 778 ft-lbs kgm meters 1 Heat Kw hrs. unit = HP hrs lb. carbon oxidized lbs. water evaporated from and at 212 F. 1 Heat-.122 watt/sq. in. unit/sq Kw/sq. ft. Ft./Min.=.0236 HP/sq. ft. Wiring Formula Ohm s law is practically the basis for the various formulae in general use for determining the proper size of wire to use to carry various currents. It is essential to know the amount of current expressed in amperes, the distance, and to decide upon the loss to allow in transmission; the best rule is as follows: The cross section (CM) of the necessary wire is found by multiplying twice the distance one way (2D) by the amount of current expressed in amperes (C) and this by the resistance of one mil-foot (10.7) and dividing by the loss in transmission expressed in volts (v), or CM = 2D x C x 10.7 or CM = D x C x 21.4 v v Comparison of Methods of Starting Squirrel-Cage Induction Motors % Full Voltage Value Voltage Motor Starter at Line Output Type Motor Current Torque Full Voltage Autotransformer- 80pc tap (60) 65pc tap (35) 50pc tap (20) Primary reactor- 80pc tap (60) 65pc tap (35) 50pc tap (20) Primary-resistor typical rating (60) Part-winding Low speed motors (1/2-1/2) High speed motors (1/2-1/2) High speed motors (2/3-1/3) Wye start-delta run (27) Note: The nominal torque values given neglect the effects of motor saturation.actual torque ratios may be more on the order of the values shown in parentheses, and it is advisable to review the actual reduced voltage starting characteristics with the motor manufacturer. 588

4 NEMA Code Letters for Locked Rotor KVA (Alternating-Current Motors) NEMA Code KVA/HP NEMA Code KVA/HP A L B M C N D P E R F S G T H U J V K DC Generator Connection (NEMA) A2 C A1 S2 S1 = (EQUALIZER IF USED) Compound Generator-Clockwise Rotation Facing End Opposite Drive, Counterclockwise Rotation Facing Drive End F2 A1 C A2 S2 S1 = (EQUALIZER IF USED) Compound Generator-Clockwise Rotation Facing End Opposite Drive, Counterclockwise Rotation Facing Drive End Note: RHEO RHEO Interchange S1 and S2 for differentially compounded generator (voltage decreasing with load). DC Motor Connections (NEMA) These connection diagrams show all leads from the armature, the shunt field and the series (or stabilizing) field brought out of the machine.the dotted connections may be made inside the machine or outside the machine as conditions require. RHEO Compound or Stabilized Shunt Motor-Counterclockwise Rotation Facing End Opposite Drive, Clockwise Rotation Facing Drive End RHEO F1 F1 F1 F1 SHUNT SHUNT SHUNT COMP COMP COMM COMM SERIES Compound or Stabilized Shunt Motor-Clockwise Rotation Facing End Opposite Drive, Counterclockwise Rotation Facing Drive End Source: ANSI/NEMA Standards for Motors and Generators. (1980). F2 SERIES A1 C A2 S1 S2 SHUNT COMP COMM COMP COMM SERIES SERIES A2 C A1 S1 S2 F2 F2 Motor Application Formulas Power Transmission by Shaft Hp =[Torque (in lb-ft) x rpm] 5250 Power to Drive Pumps Gal. per min. x Sp. Gr. x total head (inc. friction) Hp = 3,960 x eff. of pump Where Approx. Friction head (ft.) = pipe length (ft.) x [velocity of flow (fps)] 2 x ,367 x diameter (in.) Eff = Approximately 0.50 to 0.85 Sp. Gr. = Specific gravity of Liquid Power to Drive Fans Cu. ft. gas per min. x water gage pressure (in.) Hp = x Eff. The volume of gas delivered by a fan varies directly as the fan speed. The pressure produced by a fan varies as the square of the fan speed and directly as the density of the gas handled.the horsepower of a fan varies as the cube of the fan speed and directly as the density of the gas handled. Equivalent Wye Delta Networks K1 = A + B + C K2 = ab + bc + ac B a c A b C a = b = c = BC K1 A = K 2 a AC K1 B = K 2 b AB K1 C = K 2 c Power Factor Improvement of Induction Motor Loads Power factor is defined as the cos ø in the equation Pav=Vrmslrms cos ø, where the the average power (Pav) is given in terms of root mean square voltage (V), current (I), and the phase angle ø between them. Power Factor Correction: When power factor correction capacitors are used, the total corrective kvar placed on the load side of the motor controller should not exceed the value required to raise the no-load power factor of the motor to unity. Corrective kvar in excess of this value may cause overexcitation resulting in high transient voltages, currents and torques that can increase safety hazards to personnel and can cause possible damage to the motor or to the driven equipment. The use of capacitors for power factor correction, switched at the motor terminals, is not recommended for elevator motors, multi-speed motors, motors used on plugging or jogging applications, motors subject to high speed bus transfer, and motors used with open transition, wye-delta or auto-transformer starting. For such applications the motor manufacturer should be consulted before installing power factor corrective capacitors switched at the motor terminals. Recommended Maximum Capacitor Rating When Capacitor and Motor Are Switched as a Unit. For Dripproof and Splashproof Enclosures; 230, 460, and 575 Volts, 3- Phase, 60 Hertz: General Electric Type K (NEMA Design B) Only. Normal Starting Torque and Current. 589

5 Nominal Motor Speed in Rpm & Number of Poles Induction Motor Horsepower Rating KVAR KVAR KVAR KVAR KVAR KVAR Also applicable to standard wound-rotor, open-type, three-phase, sixtycycle motors by multiplying the KVAR values in the table by a factor of I.1. Recommendations and Precautions Where possible, switch capacitors through the motor control controller at circuit location 2, illustration.this avoids resizing of motor overload devices and helps minimize possibility of excessive improvement at bus. Add power factor improvement capacitors to individual motor branch circuits using data provided by the motor manufacturer recomending the maximum capacitor rating that should be switched with the motor as a unit. If power factor improvement capacitors are connected at circuit location No. 3, illustration, account for reduced line current flowing through the motor controller s overload devices. Apply power factor improvement capacitors to the bus, ciruit location No. 1, illustration, if the motor is applied with one of the following motor controllers; reversing starter (with motor plugging), wye-delta starter, open transition, autotransformer starter, part-winding starter*, or if the motor is multi-speed. Be sure to maintain bus power factor below about 95% under all conditions of motor loading to help minimize possibility of excessive improvement. * Note: Capacitor switching by the motor starter may be acceptable in some part-winding starter applications; consult applicable motor manufacturer. DISCONNECT FUSE CONTACTOR OVERLOAD DEVICE MOTOR BUS COMBINATION MOTOR CONTROLLER 2 3 Capacitor Multipliers for Kilowatt Load (To give capacitor kvar required to improve power factor from original to desired value-see sample below.) Original Power Desired Power Factor- Per Cent Factor, Per Cent Motor Terminal Amperes At Full Load Average Values for All Speeds and Frequencies Assume total plant load is 100 kw at 60 per cent power factor. Capacitor kvar rating necessary to improve power factor to 80 per cent in found by multiplying kw (100) by multiplier in table (0.583), which gives kvar (58.3). Nearest standard rating 60 (kvar) should be recommended. Single- Polyphase A-C (Induction Type) Phase A-C Squirrel-Cage and Wound Rotor Direct Current 115 Volts 230 Volts 460 Volts 575 Volts Ph 2-Ph 2-Ph 2-Ph Hp Volts Volts* 3-Ph 4-Wire 3-Ph 4-Wire 3-Ph 4-Wire 3-Ph 4-Wire Volts Volts Volts 1 / / / / / / These values of full-load current are for motors running at speeds usual for belted motors and motors with normal torque characteristics. Motors built for especially low speeds or high torques may require more running current, in which case the nameplate current rating should be used. Current in common conductor of 2-phase, 3-wire system will be 1.41 times value given. * For full-load currents of 208- and 200-volt motors, increase the corresponding 230-volt motor full-load current by 10 and 15 percent respectively. 590

6 Full-Load Currents in Amperes-Single Phase Circuits KVA X 1000 Full Load Current = Circuit Voltage KVA KVA ,000 14, Full-Load Currents in Amperes Three-phase Circuits KVA X 1000 Full Load Current = x Circuit Voltage KVA KVA ,00 12,470 13,200 14, Power Transformer Insulation Levels (1) (1) (2) Nominal Basic Insulation Low Frequency System Voltage Levels (BIL) Voltage Insulation (kv rms) kv-crest Levels (kv rms) * * Nonpreferred voltage. Table is for reference only.the selection BIL depends on system conditions and transient over voltage protection used. Copper Data Resistivity and Density (Based on National Bureau of Standards) The international annealed-copper standard of 100% conductivity, based on the Absolute Ohm, is as follows at 20 C: Resistance of a uniform, annealed copper wire one square millimeter in cross section and one meter long = ohm. Density = 8.89 grams per cubic centimeter.these values also can be expressed as: microhm cm ohm gram/meter microhm inch ohm, pound/mile ohm circular mil/ft Temerature Coefficient of Resistance The temperature coefficient of resistance at constant mass and free expansion of standard annealed copper of 100% conductivity is, per degree Celsius, (centigrade) at 20 C or at 25 C. Resistance values of copper wire at 100% conductivity given in tables at 25 C or at any temperature t 2 by means of the following equations: t 2 Rt 2 = R 25 [ (t 2-25)] = Rt t 1 Where Rt 1 = resistance in ohms at t 1, degrees C Rt 2 = resistance in ohms at t 2, degrees C R 25 = resistance in ohms at 25 C Breaking Loads of Copper Wire Breaking Load, Breaking Load, * Hard- An- * Hard- An- Diam. Size, drawn nealed Diam. Size, drawn nealed In. AWG (Min.) (Max.) In. AWG (Min.) (Max.) * Based on ASTM B1-56. Based on ASTM B

7 Copper Wire Data Bare Copper Wire Resistance at 25 C Current Carrying Approx. Cross- Capacity OD sectional 700 CM Size* Inches Area CM LB/M Ft per M.Ft Per Amp 1000MCM AWG * Sizes 1000 MCM through #8 AWG Class B concentric stranded Sizes #10 AWG and smaller solid round Typical Equivalent Delta Phase Spacings For Single Circuit Lines Voltage Equiv. Voltage Equiv. Rating Spacing - Ft. Rating Spacing - Ft CAPACITIVE REACTANCE SPACING FACTOR Xc2 MEGOHMS/COND/MILE EQUIVALENT & SPACING-FEET INDUCTIVE REACTANCE SPACING FACTOR XI2 OHMS/COND/MILE Total 60 Cycle Inductive Reactance in ohms per mile: XL = XL1 + XL2 XL1 = Inductive Reactance at 1 ft. spacing. XL2 = Inductive Reactance spacing factor. (See graph) Total 60 Cycle Capacitive Reactance in megohms per mile: XC = XC = XC1 + XC2 XC1 = Capacitive Reactance at 1 ft. spacing. XC2 = Capacitive Reactance spacing factor. (See graph) Table - 3 Maximum Number of Conductors in Trade Sizes of Conduit or Tubing (From NEC Tables 3A, 3B, 3C) Conduit Trade Size 1 3 /2 /4 (inches) /4 1 1 / / / Conductor Size Type Letters AWG, MCM TW,T, RUH RUW, XHHW (14 thru 8) RHW and RHH (without outer covering), THW TW, T, THW, RUH ( 6 thru 2), RUW (6 thru 2), FEPB (6 thru 2), RHW and RHH (with out outer covering)

8 Table - 3 Maximum Number of Conductors in Trade Sizes of Conduit or Tubing (From NEC Tables 3A, 3B, 3C) Conduit Trade Size 1 3 (inches) /2 / /4 1 1 / / / Conductor Size Type Letters AWG, MCM THWN, THHN, FEP (14 thru 2), FEPB (14 thru 8), PFA (14-4/0), PFAH (14-4/0), Z (14-4/0), XHHW (4 thru MCM) XHHW RHW, RHH (with outer Covering)

9 Lamp Data General Electric Lamp Data Watts Lamp Code Replaces Energy Savings*S Incandescent Lamps-Watt Miser 34 40A/34WM 40A A/52WM 60A A/67WM 75A A/90WM 100A A/135WM 150A 0.79 Incandescent Lamps-Watt Miser PAR (Spot and Flood) 65 75PAR/FL/65WM 75PAR/FL PAR/SP/65WM 75PAR/SP PAR/FL/120WM 150PAR/FL PAR/SP/120WM 150PAR/SP 4.20 * Over rated average life of lamp at 7 /kwh. Nominal Approx. Lamp Initial Flourescent Lamps Watts Lumens 4-Foot Rapid Start (48 ) Standard Cool White 40 3,150 Maxi-Miser II Lite White 40 3,450 Watt-Miser Cool White 34 2,750 Watt-Miser II Lite White 34 2,925 Watt-Miser SP ,900 Watt-Miser SP ,900 Watt-Miser SP ,850 8-Foot Slimline (96 ) Standard Cool White 75 6,300 Watt-Miser Cool White 60 5,600 Watt-Miser II Lite White 60 6,000 8-Foot High Ouput-800mA (96 ) Standard Cool White 110 9,200 Watt-Miser Cool White 95 8,300 Watt-Miser II Lite White 95 8,800 8-Foot 1500mA (96 ) Power Groove Standard Cool White ,000 Watt-Miser II Cool White ,000 Watt-Miser II Lite White ,900 T12 (1 1 /2 dia.) Standard Cool White ,000 Watt-Miser Cool White ,000 Watt-Miser II Lite White ,800 Approx. Length Initial Watts Bulb Finish Type (In.) Lumens Multi-Vapor Lamps (Mogul Screw Base) 175 E-23 1 /2 Clear or Diffuse MV-II 7 3 /4 16, E-28 Clear or Phosphor Std. 8 1 /4 14, E-28 Clear or Phosphor Std. 8 1 /4 20, E-37 Clear or Phosphor 1-line* 11 1 /16 28, E-37 Clear or Phosphor High Output 11 5 /16 40, E-37 Clear or Phosphor Std. or 1-line* 15 5 /6 36, BT-56 Clear High Ouput or 1-line* 15 1 /16 115, BT-56 Clear or Phosphor Std /16 110, BT-56 Clear High Output 15 1 /16 155,000 Lucalox Lamps (Mogul Screw Base) 35 E-17 Clear (Medium Base) 5 1 /2 2, E-23 1 /2 Clear 7 3 /4 5, E-23 1 /2 Clear 7 3 /4 5, E-23 1 /2 Clear 7 3 /4 9, E-23 1 /2 Clear 7 3 /4 16, E-18 Clear 9 3 /4 22, E-18 Clear 9 3 /4 27, E-18 Clear Deluxe Color 9 3 /4 22, E-18 Clear 9 3 /4 37, E-18 Clear 9 3 /4 50, E-25 Clear 15 1 /16 140,000 E-Z Lux Lamps* (For 175W mercury ballasts) 150 E-28 Clear 9 12,000 Mercury Lamps (Mogul Screw Base) 100 E-23 1 /2 Deluxe White 7 1 /2 4, E-28 Deluxe White 8 1 /4 8, E-28 Deluxe White 8 1 /4 12, E-37 Deluxe White 11 5 /16 22, BT-56 Deluxe White 15 1 /16 63,000 * May be used on approved mercury ballasts. Also available with medium base, E-17 bulb. Circlite Replaces incandescent lamps (10 dia.) 44 1,

10 Industry Standards Enclosure Types for Non-Hazardous Locations National Electrical Manufacturers Association (NEMA Standard 250) Type Intended Use and Description 1 Enclosures are intended for indoor use primarily to provide a degree of protection against contact with the enclosed equipment or locations where unusual service conditions do not exist. 2 Enclosures are intended for indoor use primarily to provide a degree of protection against limited amounts of falling water and dirt. 3 Enclosures are intended for outdoor use primarily to provide a degree of protection against windblown dust, rain, and sleet; undamaged by the formation of ice on the enclosure. 3R Enclosures are intended for outdoor use primarily to provide a degree of protection against falling rain and sleet; undamaged by the formation of ice on the enclosure. 4 Enclosures are intended for indoor or outdoor use primarily to provide a degree of protection against windblown dust and rain, splashing water, and hose-directed water; undamaged by the formation of ice on the enclosure. 4X Enclosures are intended for indoor or outdoor use primarily to provide a degree of protection against corrosion, windblown dust and rain, splashing water, and hosedirected water; undamaged by the formation of ice on the enclosure. 5 No NEMA equivalent. 6 Enclosures are intended for use indoors or outdoors where occasional submersion is encountered. 12 Enclosures are intended for indoor use primarily to provide a degree of protection against dust, falling dirt, and dripping noncorrosive liquids. 13 Enclosures are intended for indoor use primarily to provide a degree of protection against dust, falling dirt, and dripping noncorrosive liquids. The preceding descriptions are not intended to be complete representations of National Electrical Manufacturers Association standards for enclosures. Underwriters Laboratories Inc. (UL 50 and UL 508) Type Intended Use and Description 1 Indoor use primarily to provide protection against contact with the enclosed equipment and against a limited amount of falling dirt. 2 Indoor use to provide a degree of protection against limited amounts of falling water and dirt. 3 Outdoor use to provide a degree of protection against windblown dust and windblown rain; undamaged by the formation of ice on the enclosure. 3R Outdoor use to provide a degree of protection against falling rain; undamaged by the formation of ice on the enclosure. 4 Either indoor or outdoor use to provide a degree of protection against falling rain, splashing water, and hosedirected water; undamaged by the formation of ice on the enclosure. 4X Either indoor or outdoor use to provide a degree of protection against falling rain, splashing water, and hosedirected water; undamaged by the formation of ice on the enclosure; resists corrosion. 5 No UL equivalent. 6 Indoor or outdoor use to provide a degree of protection against entry of water during temporary submersion at a limited depth; undamaged by the formation of ice on the enclosure. 12 Indoor use to provide a degree of protection against dust, dirt, fiber flyings, dripping water, and external condensation of noncorrosive liquids. 13 Indoor use to provide a degree of protection against lint, dust seepage, external condensation and spraying of water, oil, and noncorrosive liquids. This material is reporduce, with permission from Underwriters Laboratories Inc. Standard for Safety for Cabinets and Boxes, UL 50, Copyright 1985 and Industrial Control Equipment, UL 508, Copyright 1984 by Underwriters Laboratories Inc. Underwriters Laboratories Inc. (UL) shall not be responsible to anyone for the use of or reliance upon a UL Standard by anyone. UL shall not incure any obligation or liability for damages, including consequential damages, arising out of or connection with the use, interpretation of, or reliance upon a UL Standard. Canadian Standards Association (Standard C22.2 Nos. 14, 40 and 94) Type Intended Use and Description 1 General purpose enclosure. Protects against accidental contact parts. 2 Indoor use and so constructed or protected that exposure to falling moisture will not impair the effectiveness of the enclosed equipment. 3 Outdoor use and so constructed or protected that exposure to the weather, to falling mositure, or to external splashing, will not impair the effectiveness of the enclosed equipment. 3R No CSA equivalent. 4 Indoor or outdoor use and so constructed that a stream of water from a hose will not result in water entering the enclosing case. 4X No CSA equivalent. 5 Indoor use and so constructed that dust cannot enter the enclosure; and accumulated dust will not result in temperatures exceeding specified values. 6 No CSA equivalent. 12 No CSA equivalent. 13 No CSA equivalent. 595

11 Degree of protection of the electrical equipment up to 1000 V a.c. and 1500V d.c. IP X1 X2 according to IEC 529 (1989) and EN (1991) X1 Protection of persons against contact with live parts Protection of equipment against ingress of solid foreign bodies X1 Protection against ingress of liquids 0 CEE-symbol Test None 0 CEE-symbol Test None Against access with hand and ingress of solid objects greater than 50 mm Against access with finger and ingress of solid objects greater than 12 mm Against access with tools and ingress of solid objects greater than 2.5 mm Against vertically falling drops Against drops of falling liquid at an angle up to 15 from the vertical Against water falling in rain at an angle up to 60 from the vertical Against water splashed from any direction (over 360 ) Against access with wires or strips and ingress of solid objects greater than 1 mm Complete protection against contact with live parts and ingress of harmful deposits of dust Complete protection against contact with live parts of ingress of dust Against water jets from any direction (over 360 ) Against water projects in powerful jets as from heavy seas Against immersion in water under defined conditions of pressure and time Against continuous submersion in water Additional letter to IP X1 X2 (optional) Additional letter Used with first characteristic numeral IPX1 Test Protection against access to hazardous parts A 0 Protection against access to hazardous parts B 0 and 1 Protection against access with a finger C 1 and 2 Protection against access with a tool D 1, 2 and 3 Protection against access with a wire 596

12 Decimal and Metric Equivalents of Common Fractions of an Inch Fraction Decimal Mm Fraction Decimal Mm. 1/ / / / / / / / / / / / / / / / ,875 9/ / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / Conversion Factors U.S. Customary Measures and Weights (Based on National Bureau of Standards) Length 1 inch = 1000 mils 1 furlong = 40 rods 1 foot = 12 inches 1 Statute mile = 8 furlongs 1 yard = 3 feet 1 Statute mile = feet 1 fathom = 6 feet 1 nautical mile = 6076 feet 1 rod = 5 1 /2 yards 1 league = 3 miles Area 1 sq foot = 144 sq inches 1 acre = 160 sq rods 1 sq yard = 9 sq feet 1 acre = 43,560 sq ft 1 sq rod = 30 1 /4 sq yards 1 sq mile = 640 acres Conversion Factors U.S. Customary Measures and Weights (Based on National Bureau of Standards) Liquid Capacity 1 gill = 4 fluid ounces 1 barrel = 31 1 /2 gallons 1 pint = 4 gills 1 hogshead = 2 bbl. (63 gal.) 1 quart = 2 pints 1 tun = 252 gallons 1 gallon = 4 quarts 1 barrel (petroleum) = 42 gallons Dry Capacity 2 pints = 1 quart = 67.2 cu in 8 quarts = 1 peck = cu in 4 pecks = 1 bushel = cu in Avoirdupois Weight (For other than drugs, gold, silver, etc.) 1 dram = grains 1 quarter = 25 pounds 1 ounce = 16 drams 1 short ton = 2000 pounds 1 pound = 16 ounces 1 long tonn = 2240 pounds 1 lb avdp = 7000 grains = grams = lb troy = lb apoth. 1 grain = 1 grain troy = 1 grain apoth. Temperature Conversion Table C F C F C F C F

13 Metric Equivalents of U. S. Customary Measures and Weights (Based on National Bureau of Standards) Length Cm = in. In. = cm Meter = ft. Ft. = m Meter = yd. Yd. = m Km = mile Mile = km Area Sq cm = sq. in. Sq. in. = sq cm Sq m = sq. ft. Sq. ft. = sq m Sq km = sq. mile sq. mile = sq km Volume Cu cm = cu. in. Cu. in. = cu cm Cu m = cu. ft. Cu. ft. = cu m Capacity Liters = cu. in. Cu. in. = liter Liter = cu. ft. Cu. ft. = liters Liter = gal. (U.S.) Gal. = liters Liter = bu. (U.S.) Bu. = liters cu. cm. Liter = qt. (liquid) or qt. (dry) lb. of pure water at 4 C=1 kg. Weight Gram = grains Grain = g. Gram = oz. avdp. Oz. avdp. = g. Kg = lb. avdp. Lb. avdp. = kg. Kg = ton (sht.) Ton (sht.) = kg. Pressure Kg per sq cm = lb. per sq. in. Lb per sq in = kg. per sq. cm. Kg per sq m = lb. per sq. ft. Lb per sq ft = kg. per sq. m. Kg per sq cm = normal atmosphere kg. per sq. cm. Normal atmosphere = bars lb. per sq. in. Pascals = lb/sq. in. Megapascals = 145 lb/sq. in. Lb per sq. in. = pascals Conversion Factors To Convert From To Multiply By # Angstrom unit... centimeters E-08 Atmospheres... mm of mercury at 0 C E+02 pounds/sq. in E+01 kilograms/sq. m E+04 Atomic mass unit... mass of electron E-04 mass of proton E+00 mass of neutron E+00 mass of A particle E+00 H, atom mass E+00 Bars... dynes/sq. cm E+06 Btu*... foot-pounds E+02 horsepower-hours E-04 kilopond-meters E+03 kilogram-calories* E-01 kilowatt-hours E-04 Btu*/hour... horsepower E-04 Btu*/(hour-sq ft)/ (gram-cal*/s.-sq. cm)/ ( F/in)... ( C/cm) E-04 Btu*/minute... foot-pounds/s E+01 horse power E-02 kilowatts E-02 Conversion Factors To Convert From To Multiply By # Btu*/second... kilopond-meters/s E+02 kilowatts E+00 Btu*/sq ft... gram-cal*/sq. cm E-01 Centimeters Hg (0 C) pounds-force/sq. in E-01 inches of water E+00 Centiposes... pound/foot-hours E+00 Circular mils... square mils E-01 Cubic feet/minute... gallons/second E-01 cubic cm/s E+02 Cubic feet/pound... cu. cm. /g E+01 Cubic feet/second... gallons/minute E+02 Cubic meters... cubic feet E+01 Degrees... radians E-02 Degrees/second... revolutions/minute E-01 Dynes... grams-force E-03 poundals E-05 Dyne-centimeters... pounds-force-feet E-08 Dynes/sq centimeter... atmospheres E-07 Electron volts... gram-calories* E-20 gram-cal*/mole E+04 cm- 1 (wave no.) E+03 kwh E-26 micrometers wavelength... ** Feet of H20 at 39.2 F.. inches of Hg at 32 F E-01 Foot-pounds-force... Btu* E-03 kilowatt-hours E-07 Foot-poundsforce/s... Btu*/min E-02 Gallons (U.S. Liquid)... cubic inches E+02 cubic feet E-01 Gal/min (of water)... pound/hr of water E+02 Gram-calories*... Btu E-03 Gram-cal*/sq. cm... Btu*/sq. ft E+00 Gram-force-cm... Btu* E-08 ergs E+02 Gram-mole Gas... cubic cm gas (0 C & 760mm) E+04 Grams-force... dynes E+02 Grams... pounds E-03 Grams of matter... electron volt E+32 Grams/cu cm... pounds/cu. inch E-02 pounds/cu. foot E+01 Grams-force/sq cm... centimeters of Hg E-02 atmosphere E-04 pounds-force/sq. ft E+02 Horsepower (mech)... foot-pounds-force/s E+02 kilowatts E-01 Horsepower hours... Btu* E+03 joule (abs) E+06 kilogram-cal* E+02 In of Hg at 32 F... pounds-force/sq. in E-01 In of H20 at 39.2 F (4 C)... centimeters of Hg E-01 pounds/sq. in E-02 pounds-force/sq. ft E+00 Joules (abs)... kilogram-calories* E-04 Kilogram-cal*... horse power-hours E-03 Kilopond-meter... Btu* E-03 ergs E+07 Kilowatt... average noon sunlight on 1 sq. m E+00 Btu* E+03 Kilowatt... horsepower E+00 Kilowatts... kilogram-cal*/minute E+01 Liter-atmospheres... Btu* E-02 Liters/kilogram... cubic ft/pound E-02 Liters/minute... cubic feet/s E-04 gallons/hours E+01 Lumens... watts E

14 Conversion Factors To Convert From To Multiply By # Newtons... dynes E+05 Newton-meters... joules E+00 Pound-celsius (Centrigrade) Unit... Btu* E+00 Pound-mol gas... cubic feet of gas (60 F at 1 atm) E+02 Pounds of H20 (4 C).. gallons of H2O E-01 Pounds of H20 at 64 F... cubic feet of H2O E-02 Pounds/gallon... grams/cu. cm E-01 Pounds/sq. in... atmospheres E-02 Radian... degrees E+01 Radians/s... revolutions/s E-01 Torricellis (Torr)... mm. of Hg. (0 C) E+00 Volt-coulomb... joules E+00 Watt-hour... Btu* E+00 Watts... foot-lb/minute E+01 horsepower E-03 lumens E+02 # E is the power of 10 by which the number must be multiplied. i.e., 4,047 E+03=4.047x10 3. Radiant watts at 5550 A. * Thermochemical. ** electron volts x micrometers wavelength = E+00. Factors for Conversion to International System (Si) Units Conversion Factors International System (SI) Units (from National Bureau of Standards Handbook 102) To Convert From To Multiply By # Acceleration Ft/sec 2... meter/sec E-01 In/sec 2... meter/sec E-02 Area Acre... meter E+03 Ft 2... meter E-02 In 2... meter E-04 Mile 2 (statute)... meter E+06 Yard meter E-01 Torque dyne-cm... newton-meter E-07 kgf-meter... newton-meter E+00 Ibf-inch... newton-meter E-01 Ibf-foot... newton-meter E+00 ozf-inch... newton-meter E-03 Torque/Length Ibf-ft/in... newton-m/m E+01 Ibf-in/in... newton-m/m E+00 Electricity and Magnetism amp hr... coulomb E+03 faraday (chem)... coulomb E+04 gauss... tesla E-04 gilbert... amp-turn E-01 maxwell... weber E-08 orested... amp/meter E+01 unit pole... weber E-07 Energy (includes Work) Btu*... joule E+03 calorie*... joule E+00 eletron volt... joule E-19 erg... joule E-07 ft-lb-force... joule E+00 kilowatt-hr... joule E+06 watt-sec... joule E+00 Energy/Area Time Btu*/ft 2 min... watt/meter E+02 Btu*/ft 2 hr... watt/meter E+00 cal*/cm 2 min... watt/meter E+02 To Convert From To Multiply By # Force dyne... newton E-05 kg-force... newton E+00 oz-force (av)... newton E-01 lb-force (av)... newton E+00 Force/Length lb-force/in... newton/meter E+02 lb-force/ft... newton/meter E+01 Heat Btu* in/sec ft2 deg F... watt/meter K E+02 Btu* in/hr ft2 deg F... watt/meter K E-01 Btu*/ft 2... joule/meter E+04 Btu*/hr ft 2 deg F... watt/meter 2 K E+00 Btu*/lbm deg F... joule/kg K E+03 Btu*/sec ft 2 deg F... watt/meter 2 K E+04 cal/cm 2... joule/meter E+04 cal/cm 2 sec... watt/meter E+04 cal/cm 2 sec deg C... watt/meter K E+02 cal*/g... joule/kg E+03 cal*/g deg C... joule/kg k E+03 Length astronomical unit... meter E+11 foot... meter E-01 inch... meter E-02 light year... meter E+15 mil... meter E-05 mile (statue)... meter E+03 yard... meter E-01 Light ft-candle... lux E+01 ft-lambert... candela/meter E+00 Mass oz mass (av)... kilogram E-02 lb-mass (av)... kilogram E-01 ton (2000 lbm)... kilogram E+02 Mass/Volume (includes Density) lbm/ft 3... kilogram/meter E+01 lbm/in 3... kilogram/meter E+04 oz mass (av)/in 3... kilogram/meter E+03 lb-mass (av)/gal... kilogram/meter E+02 Power Btu*/sec... watt E+03 Btu*/min... watt E+01 Btu*/hr... watt E-01 Cal*/sec... watt E+00 Cal*/min... watt E-02 erg/sec... watt E-07 ft-lb force/hr... watt E-04 ft-lb force/min... watt E-02 ft-lb force/sec... watt E+00 hp (elec)... watt E+02 Pressure (Force/Area) atm (760 Torr)... pascal E+05 bar... pascal E+05 dyne/cm 2... pascal E-01 gram (force)/cm 2... pascal E+01 in of Hg (60 F)... pascal E+03 in of water (60 F)... pascal E+02 mm of Hg (0 C)... pascal E+02 lb-force/ft 2... pascal E+01 lbf/in 2 (psi)... pascal E+03 Torr (mm Hg, 0 C)... pascal E+02 Velocity (includes Speed) ft/hr... meter/sec E-05 ft/min... meter/sec E

15 To Convert From To Multiply By # Velocity (Includes Speed) ft/sec... meter/sec E-01 in/sec... meter/sec E-02 mile/hr... meter/sec E-01 mile/min... meter/sec E+01 mile/sec... meter/sec E+03 mile/hr... km/hr E+00 Viscosity ft 2 /sec... meter 2 /sec E-02 poise... pascal-sec E-01 Ibm/ft sec... pascal-sec E+00 Ibf sec/ft 2... pascal-sec E+01 stokes... meter 2 /sec E-04 Volume (Includes Capacity) bushel (US)... meter E-02 ft 3... meter E-02 gallon (US)... meter E-03 inch 3... meter E-05 liter... meter E-03 oz (US fluid)... meter E-05 stere... meter E+00 yd 3... meter E-01 Volume/Time (Includes Flow) ft 3 /min... meter 3 /sec E-04 ft 3 /sec... meter 3 /sec E-02 in 3 /min... meter 3 /sec E-07 gal/min... meter 3 /sec E-05 * Thermochemical. # E indicates the power of 10 by which the number must be multiplied, i.e., 4.047E+03=4.047x10 3. Ampacities of Insulated Conductors Rated Volts, 60 to 90 C (140 to 194 F) Not More Than Three Conductors in Raceway or Cable or Earth (Directly Buried), Based on Ambient Temperature of 30 C (86 F) Size Temperature Rating of Conductor 60 C 75 C 85 C 90 C 60 C 75 C 85 C 90 C (140 F) (167 F) (185 F) (194 F) (140 F) (167 F) (185 F) (194 F) Type Types Type Types Types Types Type Types TW, FEPW, V TA,TBS, SA TW, RH, RHW, V TA,TBS, AWG UF RH, RHW, SIS, FEP, UF THHW, SA, SIS, THHW, FEPB, THW, RHH, kcmil THW, RHH, THWN, THHW, THWN, THHN, XHHW THHN, XHHW THHW, USE XHHW USE, ZW XHHW Copper Aluminum or Copper-Clad Aluminum / / / / The overcurrent protection for conductor types marked with an obelisk ( ) shall not exceed 15 amperes for 14 AWG, 20 amperes for 12 AWG, and 30 amperes for 10 AWG copper; or 15 amperes for 12 AWG and 25 amperes for 10 AWG aluminum and copperclad aluminum after any correction factors for ambient temperature and number of conductors have been applied. For dry locations only. See 75 C column for wet locations. (From National Electrical Code 1990 NFPA Table ). Fuse Sizes Useful Information To Select Proper Size Fuse, Safety Switch or circuit Breaker For Motor Circuits 1. Single Phase, Squirrel- 2. Squirrel-Cade and Syn- Cage and Synchronous Chronous Auto-Trans- Full Full-Voltage, Reactor former Starting, High Types 1 and 2 Copper Load and Resistor Starting Reactance Squirrel-Cage Motors Wire Size Current Single Elem. Fuse Single Elem. Fuse Time Delay Fuse Rating Branch Branch Branch Types of Circuit Circuit Circuit Circuit Circuit Types RHW, Motor Fuse Switch Breaker Fuse Switch Breaker Fuse Switch T, THW, Amp Amp Size Amp* Amp Size Amp* Amp Size TW THWN