Calculate grounding conductor size. (e) Grounding Electrode Conductor.

Enter the expected current rating in amperes. 250 for Three-Phase AC Motors. 120. Installing EGCs in parallel arrangements is not complicated. × 11/2 in. 3 = 162. Sep 3, 2023 · Example 1: Determine the minimum size of the equipment grounding conductor for a circuit protected by a 250 A automatic overcurrent protective device. How to Use the Calculator. Step#1: Characteristics of the Structure to Be Protected. (a) Portable Generators. Southwire's cable tray fill calculator takes the guesswork out of your project. Size (AWG or kcmil) Copper 2/0 3/0 4/0 250 350 400 500 700 800 Aluminum or Copper-Clad Aluminum * 2/0 250 350 1200 1200 Note: Where necessary to comply with 250. 122 for this 2020 Code cycle, but these changes are more organizational in nature. 15 = 32. 1) from IEEE Guide for Safety in AC Substation Grounding (IEEE Std. A heater is a device that protects a motor from thermal overloads due to excess current in the windings. 250. This calculator determines the minimum earth grid conductor size based on the short-time temperature rise limit and is based on equation 37 (section 11. The code allows the ampacityies for conductors to be determined from the tables or under engineering supervision. a 5-kW, 120/240-volt electric . Table 6. For example: 800 amp feeder you want to use #3/0 which is a 200 amp conductor 800/200=4 sets. on the whole, its cable is also available. Select Ampere Rating. 0%). We can calculate a change ratio for 2 AWG to 8 AWG as follows: 66,360 cm ÷ 16,510 cm = 4. Advanced Wire Ampacity Calculator The Motor Wire Size Calculator will calculate the proper wire size for a given motor HP and voltage. Select the wire material (Copper or Aluminum). Add up all the wire cross-section areas: 0. Enter the length of the wire in feet. To use the engineering supervision option please see -LINK to SERVICES PAGE-. square box 12 AWG THHN conductors in a 411/16 in. 66 to size the grounding electrode conductor. For example, the full-load current of a 10 HP motor at 230V is 28 Amps. a 5-kW, 120/240-volt electric clothes dryer Calculates the full-load amps, wire size, breaker size, heater size, starter size and conduit size for a given motor HP and voltage. 6 AWG TW conductors in a 4 in. Wire Ampacity (150 ft away) = 125A × 1. Elevate your solar designs with a calculator rooted in simplicity and precision, based on NEC standards. 3 m × 1 1. Conductor: May 21, 2023 · About Press Copyright Contact us Creators Advertise Developers Terms Privacy Policy & Safety How YouTube works Test new features NFL Sunday Ticket Press Copyright Jan 6, 2020 · A grounding electrode conductor must connect the neutral point of a separately derived system to a grounding electrode of a type identified in Sec. The size of the neutral conductor is at least equal to 16 mm2 in copper or 25 mm2 in aluminium. The National Electric Code (NEC) provides the minimum size requirements for conductors to prevent overheating and fire. 122 Minimum Size Equipment Grounding Conductors. The earth conductor size is calculated based on Table 5. Re 3TM CIC Labor Saving Calculator. In conclusion, when it comes to a 600 amp service, the correct ground wire size is crucial for safety and compliance with the National Electrical Code. Per the motor FLC listed in Table 430. Search Amazon for your Electrical products such as wire, tools, extension cords, and Jan 13, 2020 · 250. × 2 in. 3. The dwelling will have: a 12-kW, 120/240-volt electric range. 66, based on the area of the ungrounded secondary conductor [Sec. Therefore, you must size the grounded conductor to carry 190A. The neutral conductor is protected against short-circuit, in accordance with the following Sub-clause G-7. Assumptions for Calculations. Feeder conductors shall have an ampacity not less than required to supply the load as calculated in Parts III, IV, and V of Article 220. Step#2: Risk Assessment Study. The requirements in these sections call for all conductors of The wire size chart below shows allowable ampacities of insulated conductors rated up to and including 2000 Volts, 60°C through 90°C (140°F through 194°F), not more than three current-carrying conductors in raceway, cable, or earth (directly buried), based on ambient air temperature of 30°C (86°F). This applies to three-phase AC motors. Canada whose results are shown in Appendices. square box 14 AWG TW conductors in a 3 in. *See installation restrictions in 250. 1 day ago · The calculator is designed to accept the total line voltage and current of the combined three cables. Jul 2, 2024 · A g A_\text{g} A g is the grounding conductor fill volume allowance; and; n g n_\text{g} n g is the number of grounding conductors. You must size a grounding electrode conductor for a single separately derived system in accordance with 250. 134 (B) is in order. Conductor - Choose the material used as a conductor in the wire. Wire Size - Choose the size wire in the circuit. with tin or zinc plated connectors. GI housing is usually available in the market. The size of the grounding electrode conductor to the grounding electrode(s) shall not be smaller than given in 2. 122, which allows for a smaller gauge ground wire, such as a # 10 or #12 AWG, to be used in this portion of the PV system. 4(B), and (D) and solves many common design Feb 11, 2015 · Let’s say the ungrounded conductors are increased to a 2 AWG, Type XHHW, copper conductor due to voltage drop. Explained in Article " Design Calculations of Lightning Protection Systems – Part Two ". Maximum Allowable Ampacities for Conductors in Raceway, Cable or Earth (30°C) Maximum Allowable Ampacities for Conductors in Free Air (30°C) Maximum Allowable Ampacities for Conductors in Raceway, Cable or Earth (40°C) Maximum Allowable Ampacities for Jul 16, 2013 · Selection of a bonding conductor size is governed by Rule 10-814 (1). Class I – Copper: Minimum Gauge is 2 AWG, with a minimum individual strand size of 17 AWG. Units for wire size are AWG or kcmil. PV System Equipment Ground. The dwelling will have: * a 12-kW, 120/240 volt electric range. To calculate an appropriate ground conductor size, enter the information below. I see other systems with #10’s for the DC and #8 or #6 ground in the EMT. 2 Amps. NEC Table 310. Mar 1, 2017 · 250. An oversized conductor could be a waste of money, and an undersized conductor might not be able to handle the required current flows, which is why choosing the correct wire size is so important. Earthing system calculation for steal factory substation 132/11kV, 1×30/40MVA. 3 m X 11. Note: These values are based on allowable ampacities of insulated conductors rated up to and including 2000 volts, not more than three current-carrying conductors in a raceway, cable, or Earth, single-insulated conductor in free air, and an ambient air temperature of 30°C (86°F). There are additional minor revisions that can be found in Section 250. Do include “spare” conductors that are intended to be energized at some point in the future. The equation is based on the IEEE Guide for Safety in AC Substation Grounding (IEEE Std 80-2013), section 14. Dec 25, 2020 · Earthing Grid Conductor Sizing. 4 and 250. This simple calculator can only do calculations with copper conductor and aluminium conductor. The main purpose of doing grounding in Download Ampacity Chart PDF: Understanding Ampacity: Ampacity refers to the maximum safe current a conductor can carry continuously under specific operating conditions without exceeding its designated temperature limit. The required resistance will be 2400 / 400 = 6 Ohms. Size the grounding electrode conductor per Sec. 122 of the NEC, which is the National Electrical Code. This conductor shall connect the grounded conductor of the derived system to the grounding electrode as specified in 250. A great tool to help electricians, engineers and contractors answer the question, "What size conduit do I use per the NEC®?" The app will calculate the conduit fill percentages and jam probability for multiple conductors per NEC® Guidelines. In equation form, we express Calculate the size of ground wire for a given circuit or motor by selecting the ampere rating of the circuit protection device. Table 250. com/bonding. 5565 + 0. Click on the “Calculate” button to get the result. Wire Size For 100 Amp Sub Panel 150 Feet Away. I also question that if a larger ground is required, can it be run next to the MC cables. 2(A)(1) General. The circular mil values are added together (400 plus 400) to result in 800 kcmil copper now required for the circuit Question: 12. 24 (D) for sizing grounded conductors, and 250. Minimum Wire Size Formula for Single-Phase Circuits. 15(B)(16) Conductor Size, OCPD, Voltage Drop, and Equipment Grounding Conductor Size Calculator by electrician2. 1 in AS/NZS 3000:2018. Now we need to add the 30% amp boost (+20% per every 100 feet, hence +30% for 150 feet) to these 125 amps: Min. Note: The results of this calculator are based on conductor temperatures of 75°C. 1250. 52, size the branch-circuit short-circuit and ground-fault protection devices by using multiplication factors based on the type of motor and protection device. The down conductor is properly listed in the standard as a “Main Conductor Cable”. Using NEC Chapter 9 Table 5, we’ll calculate the cross-section area of each wire. Dec 8, 2023 · The neutral point of transformer to the earth ground network provides a reference point of zero volts. The circular mil value of a 3 AWG conductor is 52,620 circular mils, as provided in NEC Table 8, Chapter 9. Factors such as the type of grounding system and the size of the grounding electrode conductor should be considered during installation. 8-108. Optionally, enter the allowable voltage drop as a percentage (default is 2. Switch to 600 kcmil which is a 420 amp conductor 800/420=1. 4(A)(5) or (B)(4), the equipment grounding conductor shall be sized larger than given in this table. According to the third row, “2/0 or 3/0” the size should be 4 AWG copper or 2 AWG aluminum. The minimum feeder-circuit conductor size, before the application of any adjustment or correction factors, shall have an allowable ampacity not less than the noncontinuous load plus 125 percent of the co 6000. Distance - Enter the one-way length of the wires in the circuit in feet. 122 and used a 600KCMIL conductor but my thought is that it should be done from Article and Table 250. 0732 + 0. The Ground Conductor Size Calculator will calculate the proper ground conductor size for grounding raceways and equipment based on ampere rating or setting of automatic overcurrent protection device in circuit ahead of equipment. a 12-kW, 120/240-volt electric range. However, you must now increase the size Jun 17, 2022 · The method to establish a base minimum size for the grounded (neutral) conductor hasn't really changed, spoiler alert, but at the least easier to understand. The dwelling will have: • a 12-KW, 120/240-volt electric range. Get accurate results and stay within NEC guidelines. Jun 2, 2023 · Ground Wire Size Calculator. Common conductors are copper and aluminum. Insulation - Select the thermal rating of the insulation on the wire. The grounded neutral conductor of a 4-wire, 3-phase system supplying nonlinear loads must be the same size as the ungrounded phase conductors. Solution: Enter table 250. 30(A)(4). Calculate Conductor Size (AWG) Calculate Conductor Size (AWG) May 21, 2018 · The motor full-load current, the current used to determine the ampacity necessary to properly size motor circuit conductors, is found in Article 430 using Tables 430. A building has a 600A protection device for a feeder with a demand load of 570A. Calculate the minimum size of copper service-entrance conductors and grounding electrode conductor required for a residence containing the following: floor area is 24 ft × 38 ft (7. 15(B)(16-17). Voltage:Amperes: Phases: Single-Phase Three-Phase. The frame of a Jan 10, 2008 · I have a new pad mounted 75 kva transformer (13. for a 4. Just match the insulation type to the wire gauge in the NEC table. For tripping systems, which rapidly de-energize a faulted circuit, a 10-second-rated NGR is typically recommended; 30- and 60-second variants are also available. Part II: Motor Circuit Conductors will demonstrate how to size motor circuit conductors. The minimum size wire-type EGC for a 400A feeder is normally a 3 AWG copper, according to Table 250. Back to all tables. Order special three conductor cables which contain larger sized EGCs. This ensures safety and efficiency in your electrical installations. This equipment-grounding requirement is only for equipment Apr 19, 2023 · For such installations, it is best to use an insulated conductor and to remove the insulation where bonding connections are made to the cable tray, raceways, equipment enclosures, etc. Study with Quizlet and memorize flashcards containing terms like Determine the maximum number of conductors permitted for each of the following applications in accordance with Article 314. One of these wires is a ground wire which can be sized down. 3 (B) and 250. The line to Neutral Voltage will be 4. The industry’s first estimator showing the reduction of installation labor for Southwire® Cable-in-Conduit (CIC) compared to pulling cables into PVC ducts. To develop an understanding of the requirements in 310. 2, equation 57 and essentially combines the resistive properties of a metal plate, conductors and the depth at which it is buried. Here’s the best way to solve it. i. 16 kV System Neutral Grounding Resistor rated at 400 A. 1200. The conductors for the secondary side of the transformer are sized as 1/0 copper. Service Conduit Size (threaded, rigid metal): 27. 0243 + 0. The equipment grounding conductor sizes for 15A -30A circuits are easy to r Nov 2, 2022 · What is Grounding Conductor and How to Calculate its Size - Grounding, also called earthing, is defined as a process of connecting non-current carrying parts like metallic frame of electrical device or some electrical parts of power system like neutral point of a star-connected system to earth or ground. NEC 690. Go to the next larger size, 300 A, and select size N° 4 AWG copper or N° 2 AWG aluminum or copper-clad aluminum. System Grounding - Select system grounding method (either grounded or ungrounded/high-resistance grounded). 2. 700. Try our other 12 Free Electrical Calculators. The trouble with recency bias is that every site seem­ingly winds up having to look like the last one—it is wrong to think that every design must follow the same methods and layouts. For a 50A OCPD, according to Table 250. 122 (F), a brief review of the rules in 300. Copper. Example#2: If a second service equipment with service-entrance conductor of 3 AWG is added to the case in example#1, Determine: This ground wire size calculator determines the appropriate wire gauge for grounding electrical systems based on parameters like wire material, length of wire, current rating, and allowable voltage drop. 248 for Single-Phase AC Motors, and 430. 80-2013). 12. Load. Alright, as we have calculated before, we need at least 125 ampacity wire to handle 100 amp current. Solution: Use Table 250. The equation for the area of a single wire is modified to: A = \frac {\sqrt 3 I \varrho L} {V} A=V3IϱL. 50. Simply enter the conduit type and size, then specify your Apr 16, 2021 · The influence of triplen (Harmonics of order 3 and multiple of 3) harmonics must be given particular consideration or. 122. The wire ampacity rating chart provided by the NEC (see below) is used in conjunction with the ambient temperature rating correction factor and the Gap Between Conductors - Typical range for gap between current-carrying conductors is 13 - 152 mm. The size of the conductor is not helpful; it is how it is routed. Ensure your grounding decisions are in line with Mar 25, 2021 · Basically you take the size of the feeder and divide by the number of sets or divide by the conductor ampacity for the conductors you want to use. This Rule states the following: “10-814 (1) The size of a bonding conductor shall be not less than that given in Table 16, but in no case does it need to be larger than the largest ungrounded conductor in the circuit . 02. Like a normal power cable under fault, the earthing grid conductors experience an adiabatic short circuit temperature rise. This spreadsheet calculates the following parameters of a neutral earthing transformer: Total capacitive charging current ( It ). The following addresses a couple of basic sizing examples for paralleled equipment-grounding conductors. 14(C)(1)(a)]), the conductor must be a 6 AWG THHN rated 55A. The factor of 3 is needed to convert between the system's phase current and line current. ”. Conclusion. 3 - Sizing grounding conductors in parallel: Q. 2011 Code Language: 215. 30(A)(5)]. 24 (D) (2) specifically for our Two or More Raceways or Cables installations. This calculator applies 2005 NEC Table 310. Feb 15, 2023 · Simply increasing the equipment grounding conductor size is not adequate in all cases. Approximately 265 Sqmm when multiplied by the safety factor. Note: View wire size charts from the list below. MikeHolt. The calculation is done using the software CDEG MultiGround TM SES – Safe Engineering Services & technologies ltd. However, in this case, 30×10 sqmm, 20×15 sqmm cable selection will be better. . Wire Size Calculator. 120 volts 208 volts 240 volts 277 volts 347 volts 480 volts 600 volts. Do not include equipment grounding conductors, and do not include neutral conductors that meet the exception conditions in NEC 310. List of tables and charts for wire size, ampacity, voltage drop, and motor amps and to help you determine proper wire size. Therefore, the heater must be sized for 28 * 1. 122 Equipment Grounding Conductor, Sizing – https://www. 3 m x 11. com. This calculator will also give you motor amps and recommended breaker size, starter size, heater size and conduit size. Determining the minimum size of the earthing grid conductors is necessary to ensure that the earthing grid will be able to withstand the maximum earth fault current. The factor of 2 disappears, as there is no return 5000. Contains the maximum distance between condcuit supports for rigid metallic and non-metallic conduit. According to the NEC, the overload rating must not exceed 115% of the full-load current of the motor. The size of the grounding electrode conductor at the service, at each building or structure where supplied by a feeder(s) or branch circuit(s), or at a separately derived system of a grounded or ungrounded ac system shall not be less than given in Table 250. 122 – Minimum size equipment grounding conductors for grounding raceway and equipment The Ground Conductor Size Calculator will calculate the proper ground conductor size for grounding raceways and equipment based on ampere rating or setting of automatic overcurrent protection device in circuit ahead of equipment. * a 5-kW,120/240 volt electric clothes dryer Mar 29, 2020 · STEP #1: Calculate the wire cross-section area. 16 and accompanying code sections and notes to find the wire size and minimum and maximum overcurrent protective devices (OCPD) for branch circuits and feeders per Section 240. Mar 24, 2019 · Grounding Electrode Conductor. To calculate ground wire size, use the Ground Wire Size Calculator. This Apr 26, 2004 · Wire Size Calculator - Above Ground. 250 A is not listed. 16 kV /√ (3) = 2400 V. 66 Size of Alternating-Current Grounding Electrode Conductor. 6m). Selecting the appropriate wire size for a circuit is crucial to prevent overheating Select the material of Copper or Aluminium for active conductors. I see many systems installed with #10’s for the DC and #10 ground in EMT. 6 m). Example No. An NGR dissipates P=I2R (or P=IV) power, in the form of heat, for the duration of a ground fault and must be able to do so, repeatedly, for its time rating. NEC Table 250. Spreadsheet to calculate the size of neutral earthing transformer. The installation shall comply with Part 2. 0181 = 0. 15 Portable and Vehicle-Mounted Generators. 118 Types of Equipment Grounding Conductors. 66, based on the total area of the largest secondary ungrounded (hot) conductor. Select the active conductor size within the range from 1 to >630 mm2. 15(B)(5). Aug 16, 2021 · I’m looking at a project that has parallel 4500A MCB switchboards and I’m confused with the grounding requirements. The equipment grounding conductor run with or enclosing the circuit conductors shall be one or more or a combina- tion of the following: (1) A copper, aluminum, or copper-clad aluminum conductor. For long conductor runs where voltage drop may be an Nov 1, 2000 · Size each parallel equipment-grounding conductor based on the ampere rating of the overcurrent device protecting the circuit conductors in the raceway or cable, per Table 250-122. It appears that the engineer had sized the grounding electrode conductor based on Table 250. Aluminium. 17, based on the largest ungrounded supply conductor. (amps) (required) Nominal Circuit Voltage. 5) / 80. Mar 1, 2021 · The size of the grounding electrode conductor is based upon the size of the largest ungrounded service-entrance conductors or ungrounded derived conductors (such as for a separately derived system) or the total equivalent area for parallel conductors (AWG/kcmil). This calculator uses the tables only. 8369 in². 800. Choose the amperage rating of your circuit’s overcurrent device to calculate the appropriate ground wire size based on the National Electrical Code (NEC). An equipment grounding system is dirty and a poor bonding plane—also not true. 1648 + 0. Unlike the first four components we considered, according to the 2020 NEC®, we should base the grounding wires' volume allowance on the largest equipment grounding conductor or wires. Common conductors are copper For voltage-drop reasons, or due to circuit capacity needs, the 600 kcmil conductor is increased in size from 600 kcmil to two paralleled 400 kcmil copper conductors for each ungrounded phase conductor and the neutral conductor. This takes into account correction factors for voltage drop, temperature and the number of current-carrying conductors. However unlike a fault The ElectriCalc Pro electrical calculator easily calculates grounding conductor wire sizes. Insulation: 60&degC 75&degC 90&degC. Advanced Physics questions and answers. You can use single or multiple service entrance conductors to find the grounding electrode conductor for AC systems. 5 Amps. Conductors per Phase. 4 have mandatory application. The size of the EGCs will depend on the rating or setting of the circuit's protective device as per NEC Table 250-95. 9= 2 sets. For paralleled three conductor cables installed in cable tray to be in compliance with the 1996 NEC, one of the following options must be selected: A. Example 1: A 4,000-ampere (A) feeder is installed in 10 PVC conduits in a parallel arrangement, each containing four 750 copper conductors. (e) Grounding Electrode Conductor. 6000. = 176. Search Amazon for your Electrical One of these wires is a ground wire which can be sized down. Avoiding errors Once the current rating is determined, the Resistance or Ohmic Value of the resistor is calculated by dividing the Line to Neutral Voltage by the Current Rating. Contains recommended ground conductor sizes based on over-current protection devices in circuit. Table 16 offers the code users a criteria for Apr 6, 2018 · Class I materials are required for structure less than 75-ft in height, and Class II Materials are required for buildings greater than 75-ft in height. Determines minimum recommended ground conductor size for copper and aluminium conductors based on ampere rating of over-current devices in the circuit. The Circuit. Take the value of 52,620 circular mils and For three-phase circuits, four wires are required. 66, Earth Grid Conductor Sizing Calculator. a 5-kW, 120/240-volt electric clothes dryer consisting of a 4-kW, 240 Mar 2, 2021 · The Table now requires a 1250 kcmil conductor for this application. device box 14 AWG THW conductors in a A simple tool to calculate wire sizes. Calculate the minimum size of copper service-entrance conductors and grounding electrode conductor required for a residence containing the following: floor area is 24 ft X 38 ft (7. Enter the information below to calculate the appropriate wire size. 122: Minimum Size Equipment Grounding Conductors for Grounding Raceway and Equipment. Use the following formula to calculate the minimum wire size for a DC or single-phase AC circuit: Earth Conductor size, √ (20000 2 × 0. 707 / 80. Service Panel Size (minimum): Calculations are based on the Canadian Electrical Code, Part I - 2012, 22nd Edition. Calculate the minimum size of copper service-entrance conductors and grounding electrodel conductor required for a residence containing the following: floor area is 24 ft x 38 ft (7. This is in accordance with Table 250. NEC Ground Wire Size Calculator. For ambient temperatures other than 78°F - 86°F, or more than three current-carrying conductors in a raceway, cable or Earth, use the Advanced Wire Ampacity Calculator. This is based on NEC NFPA 70E Table 250. Fault Current (Amps): Grounding Conductor Material:. 66 and a #3/0 would be sufficient. e. 66 it seems that I can size the ground conductor as small as #6 copper. This calculator is based on NEC (NFPA 70®: National Electrical Code® (NEC®), 2014 Edition) Table 310. 45(A) requires that equipment grounding conductors for PV source and output circuits be sized in accordance with NEC table 250. May 1, 2004 · Per Table 310. When using multiple conductors, the ElectriCalc Pro uses the equivalent Circular Mils to find the grounding electrode conductor based on Jan 16, 2007 · Where equipment grounding conductors are installed with paralleled feeder conductors, the requirements in 310. Part (c). 4(B), and (D) and solves many common design Jul 14, 2022 · The earthing system is designed so that the allowable touch and step voltages do not be exceeded. A conductor used to connect the system grounded conductor or the equipment to a grounding electrode or to a point on the grounding electrode system. 16 (60°C terminals [110. The reference is now 250. 8 KV - 480Y/277V 3PH, 4W). * These earthing conductors shall only be used where incorporated in a multi-core cable or flexible cord, other than a lift Aug 11, 2019 · From seeing systems installed most installers seem to be all over the place for the ground sizing. Jul 1, 2002 · Grounding Electrode Conductor. The dwelling will have: . Neutral earthing transformer secondary current. The size of the Main Bonding Jumper, Grounding Electrode Conductor, and Grounded Electrode is defined by table 250 Mechanical Engineering questions and answers. 8 Sqmm. and a picture to help make things a bit more clear. 2. The transformer needs to be grounded but I was unsure about the size of the grounding conductor. Jun 25, 2020 · 250. You can calculate the ampacity rating of a wire or conductor by referencing the chart indicating the allowable wire ampacities of insulated conductors that is provided by the National Electric Code. Looking at Table 250. Current is measured in amperes (amps). This calculator also provides wire size correction factors for temperature, number of conductors in a raceway, and voltage drop for long wire runs. Calculate Your Conduit Fill Percentage. This conductor shall be solid or stranded; insulated, covered, or bare; and in the form of a wire or Suppose you have a box with 10 wires, where the largest conducting wire size is 12 AWG, the number of devices is 5, and there are 10 grounding conductors with the largest grounding wire size being 12 AWG, determine: Grounding wire volume; Equipment grounding fill volume; Total volume allowance needed; Total box fill volume; Solution: Given that Nov 6, 2023 · In general, the sizing of earthing conductors is based on the following principles, we will discuss earthing cable size as per IEC 60364–5–54: Maximum Fault Current: The size of the earthing Sep 1, 2000 · Solution: You must size the grounded (neutral) conductor based on the largest ungrounded phase conductor. 122, a 10AWG was originally acceptable for use as the EGC. Also, In above Article, I indicated that the risk assessment study can be done by (4) different methods as follows: Adjustment factors range from 80% for 4 to 6 conductors, all the way to 35% for 41 or more conductors. Ground Conductor Size Calculator. = 20000 × 0. yv gk dq ls pz rq ze zg xt ab