how to calculate cable size in sq mm formula

So you now have a cross-sectional area for your cable. Nominal area of conductor 1 1.5 2.5 4 6 10 16 25 35 50 70 95 120 150 185 240 300 400 500 630 800 1000 of wire x dia. (1) 2 No’s of 3.5Cx300 Sq.mm XLPE Cable having 59.7mm Outer Diameter and 5.9 Kg/Meter weight (2) 2 No’s of 3.5Cx400 Sq.mm… Hence the cable rating formula can be written as, Cable size = 1.5 x Full Load Current. Formula is, I=Load (in kW)/(sqrt(3)*V(in kV)*p.f) (A) The current obtained has to derated since the cable is designed to operate at a defined temperature. Calculate cross-section and conversion factors for cables and wires Current-carrying capacity: tables (Extract from VDE 0298 T4 06/13 tables: 11, 17, 18, 21, 26 and 27) Conduit cable … of wire =0.345 mm thanks Calculate Size of Cable Tray for Following Cable Schedule. for the Area 800 Sq.mm [80 x 10 mm], Current Carrying Capacity will be 960A.., Then additional one Run of Busbar needed to carry the Current of 1067A. We wrote this article because every single day we are asked by electrical engineers, electrical contractors, and others in the electrical construction field about “How to Size a Cable“. The formula for calculating cable size for single phase circuits is wire circular mils = (conductor resistivity)(2)(amps)(one way distance in feet) / allowable voltage drop. Wire size = 22/7 x dia. Standard Wire & Cable Company can supply you with the right sizes, types, and quantities of product you need to keep you on schedule and your management happy. of 3 Core unarmoured cable.. Current Rating Of Wires & Cables 25 35 50 70 95 120 150 185 240 300 400 500 630 800 1000 Sq. 219.98 sq. If 6 Core cable is not available, use 2 Nos. mi. so, 1.25xIn= 62.64A so choose 80A Cable rating of 25mm2. Cable Size Calculations Calculations // Based On Motor Horse Power HP and Specified Current. Code inspectors measure the diameters of wires to be sure they are safe for use in buildings. Now, choose the next largest cable size from the Table below. The wire diameter, or wire gauge, determines the load it can safely carry. Example: If you’re using electrical metal tubing (EMT) conduit, you’ll see that the closest size that you need is a 1 in conduit, which gives you a 39% fill. We will make it for you. Cable Tray should be perforated and 20% spare Capacity. When load is in KW=V*I, you are aware of the voltage you are gonna use.So You Can calculate the maximum current that the cable has to carry. Online electrical calculator which helps you to calculate the size of copper, aluminium wires in an electrical circuit. When calculating the cross section according to the above formula, the result is a value in square millimeters \(mm^2\). Calculate the load current from the load data available. Calculate Cable Size and Voltage Drop: Calculate Voltage Drop and Size of Electrical cable for following data. NO guarantee as to the accuracy of these values is given. A circular mil is a unit of area, equal to the area of a circle with a diameter of one mil (one thousandth of an inch or 0.0254 mm). Cable Sizing & Selection. Download Electrical Cable Size Calculator Excel Sheet Cable sizing is done based on three parameters: Load current, Short circuit current carrying capacity, Voltage drop. LV and MV cables up to 33 kV with current capacity in accordance with BS 7671, ERA 69-30 and IEC 60502. Cable are laying in Single Layer in Cable Tray. How To Use The Cable Size Calculator 1 - Enter percentage cable loss acceptable [normally approx 2 or 3%]. Electrical Details: Electrical Load of 80KW, Distance between Source and Load is 200 Meter, System Voltage 415V Three Phase, Power Factor is 0.8,Permissible Voltage drop is 5%, Demand Factor is 1, Cable Laying Detail: Cable is directed buried… 3 - Enter max amps to be carried by the cable [amps = watts / voltage]. of 3 Core unarmoured cable. mm cable then go up to 3.3 sq. It corresponds to approximately 5.067 × 10 −4 mm 2.It is a unit intended for referring to the area of a wire with a circular cross section. One of the most important aspects of designing and building any part of a vehicle electrical system is determining the correct size and type of cable to use for each circuit. All your cables, for all your projects. This formula is based on Ohm's Law. meter and copper conductor has Rs 3.0 per sqmm, hence aluminium cables are much cheaper., However, in this article, we are going to see how to get cable capacity using Aluminium and Copper Current Carrying Capacity Calculation chart. Find the type of conduit that you want to use in table 4. 4 - Enter length of cable run required [power source to load]. Find your … .Then you need to know the current density of the material you are going to use as cable.If the material is copper,then it can allow 4 ampere/square mm. In most instances, the size of cable should be printed on the sheath, but if not you will need to calculate the diameter of the wire to determine its size, which means working out the area of a circle e.g. thermoplastic then table 4D4A column 5 would apply i.e. Example: Let’s we calculate required cable sizing for 5.5kW/7.5HP motor which is … Single Phase Circuits Formula Wire Circular Mils = 2 x Specific Resistance x Amperes x Distance / (Voltage Drop / Source Voltage) Wire and Cable Metric Calculations Dimensions Length mils x 0.0254 = mm (millimeters) inches x 25.4 = mm feet x 0.3048 = m (meters) miles x 1.609344 = km (kilometers) Area circular mils x 0.0005067 =mm 2 (square millimeters) sq. Required Cable Size (mm 2) Voltage Drop (volts) Percentage Drop (%) Load (Amps) = Reset. Cable size calculation formula: The cable size is equal to the 1.5 times of the full load current of the motor/load. And they should be checked with an electrician. Get the cable size corresponding to this derated current from the catalog. ft. x 0.092903 = m 2 (square meters) sq. the circular piece of wire. Therefore, the next largest line is always used. Distance between each Cable is 10mm. Cable Size. MM For example, if the above Cable Size Calculator says you need 3.0 sq. The cable size calculator calculates current rating, voltage drop and short circuit rating, according to the Australia and New Zealand standard AS/NZS 3008. in x 645.16 = mm 2 sq. Cable Sizing Software - select, size and manage your power cables using myCableEngineering. The n gauge wire diameter d n in millimeters (mm) is equal to 0.127mm times 92 raised to the power of 36 minus gauge number n, divided by 39: d n (mm) = 0.127 mm × 92 (36-n)/39 . Custom cable and custom heat shrink shapes are another of our specialties. Step 2: Derating factors will be available in cable catalog. A typical electrical cable contains one thick wire wrapped by an outer jacket. As we have established above, how you identify electrical cable size is through the size of wire it houses e.g .1.5mm cable houses 1.5mm wire. 0.127mm is the diameter of gauge #36. Had the cable insulation been PVC i.e. If 6 Core cable is not avaible, use 2 Nos. Calculate Min. mm Step 4: Find your conduit fill Back to your NEC book. of wire /4 sq mm wire size = 1.5 sq mm dia.of wire =root of ( 1.5/(22/7 x 4)) dia. Overview. mm copper cable 1 mtr length weight to be find There is 100mm² in 1cm², and there is 100cm in 1m copper has a density of about 8.92g/cc, so 2.4cm² x 100cm x 8.92 = 2141g, or 2.14kg per meter. If the calculation yields \(3.6 \ mm^2\), the next larger cable is laid with \(4 \ mm… But the cost to loss point of view, i.e the cost of 3 core 35sqmm aluminium cable has Rs 1.6per sq. Enter your proposed cable size,type of insulation,Voltage,ambient temp (30 is norm) your cable length and circuit load in Amps. mm / 0.4 = 549.95 sq. How to calculate the size of MCBs while designing a circuit POST BY – Z Express MEP Design Consultants ( zxpress.in ) To decide the number and types of MCB/ ELCBs in your office/ home, you must note down the number of electrical equipment used in your premises. Cable Sizing Calculator AS/NZS 3008. * 1.5 sq mm for point wiring – 2.5 sq mm for it’s circuit ( less than 800 watt per ckt) * 2.5 sq mm for 5 A light plug – max 3 plug points in one ckt – 4 sq mm ckt * 4 sq mm ckt for 16/5 A (max 2 sockets) * Sub-main / main ckt as per load calculation * Earthing – earthing wire should be copper wire of same size … This excel sheet does the cable size calculation in three steps below: Step 1: Calculate the load current from the load data available. Step 1: APPLICABLE CODES & STANDARDS : IS-3961: Recommended current ratings for Cables. yd. Related Resources: Download Excel versions of our Cable Calculators from our Free Resources page a bonus Voltage Drop Calculator. Caution - for Guidance ONLY. Cable Selection, Copper Only, up to 25mm², above this Cable Reactance must be considered. 2 - Enter nominal system voltage [or pv array voltage for solar cables]. If you need a non-stock item, don't worry. Other factors … Cable size normally 20-25% higher than breaker to avoid cable heat/burn accident in overcurrent fault. Table 4E4B, column 4 suggests Z = 1.15 milli-ohms Ib = 112 A for normal FLC Too small a cable size and you'll run the risk of generating heat in the cable; too large and you'll be wasting money on copper you don't need. Not suitable for ring mains! x 0.836127 = m 2 sq. 240 sq. Cable Size Calculator. The following formula can be used to calculate the approximate area of a multi-strand cable where both the diameter of an individual strand and the strand-count are known: s = (πd 2 / 4 (to get the area of a single strand) S = n.s (to get the approximate area of a number of strands) Where: mm, which is 12 AWG. Wire cross sectional area calculation How to size a cable, Conductor sizing per the [NEC] National Electrical Code Experts in the USA. 163 A and a 50 sq mm PVCSWAPVC would be used. We have been doing this for companies since 1947. To calculate the cross sectional area (CSA) of a cable, you have to use a micrometer to verify its diameter, then divide the diameter by two to get the radius (r). This will rarely fit exactly on a commercial cross-section. Input data: Motor voltage (V L-L), Motor horsepower, Cable Temperature Rating (°C), Ambient Temperature (°C), Cable Length (ft) and Acceptable Voltage Drop (%). Circle cross-sectional area to diameter and vice versa cross section conductor diameter intersection AWG calculation and conversion electric cable formula wire and wiring American Wire Gauge thick cross section area of a solid wire formula conductivity resistivity stranded wire litz length current - Eberhard Sengpiel sengpielaudio For three-phase circuits, the formula varies. 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