I  needed to run about 95’ of 6awg  240V 50A service from my house panel out to a new woodshop, and being able to get 100’ 6 AWG THHN/THWN spools at a good price from you worked out well!”. I'd guess though actual load probably wouldn't even reach 50 amps. 4 is bigger in size than No. Commonly available 60 amp panels are usually limited to 8 or more slots. The following are the maximum lengths of cable you can use while still maintaining a 3 percent voltage drop for the given wire size (AWG) and circuit voltage. Get daily tips and tricks for making your best home. So can I run a bigger wire for the first 50 feet then go down a size for the last 100 feet. CONTACT Your email address will not be published. All conductors of electricity, including wires, impose some resistance to the flow of electricity. Panel Options for a 50 AMP Hot Tub 220 Volt Circuit Electrical Question: Hello Dave, I am installing a hot tub that calls for 50AMP service. This can lead to decreased performance, unnecessary wear, and even premature failure of electrical equipment. What Gauge AWG Wire to Use for Solar Electric Systems. I am wondering what size aluminum I would need to feed it, and if I can use a smaller pvc. Select wire size: Select conductor type: Choose maximum voltage drop (%): Calculate Reset. This is my 100-amp about halfway done, with the 'combined' 100-amp-labeled main breaker at the top instead of a 2-pole 50. The solution is simple: Keep the total load on the circuit to 80 percent or less of total capacity. 2) At your main electrical panel you could install a couple of feet of 6 AWG stranded copper or 4 AWG stranded AL for the 50 amp breaker. No. Wire size for a 100 amp sub panel 200 feet away [ 8 Answers ] I have a 200 amp main panel in my house and I just built a garage and am planning on putting a 100 amp sub panel in the garage. 100 yards = 300 foot. Outdoor circuits, however, are often quite long and the voltage drop can be significant. Enter the total amperage on the circuit; also enter one half of the total length of the circuit. This video shows what size wire to buy when installing or upgrading an electric service panel. What’s the Difference Between SOOW, SEOOW, and STOW Portable Cord? Wire size for a 100 amp sub panel 200 feet away The garage is about 200 feet from my house and it has a 2 inch pvc stubbed out underground. I'm trying to find out what size wire i will need to run a sub panel out to a new shop I am building on my land. Types THWN and RHW are the most commonly used ones. As the length and temperature increases from subpanel to main, you will require a lower gauge, thicker wire to manage the load. Introducing "One Thing": A New Video Series. Grounding a Sub Panel at a Detached Building Electrical Question #1: Do I need to run a ground wire for a 200 amp sub panel that is 200 feet away from the main panel? However, if the cable run is long, as underground runs often are, you may need to increase the wire size to account for voltage drop—a loss of voltage in the circuit caused by the natural resistance in the wires. Our customer Steve, a skilled project engineer sent in these pics from a home project he recently completed. Feeder circuits supplying subpanels are 240-volt and require a … EMAIL SPECIALS I have a sub panel in the basement that has 100 amp service its 60’ from the meter. The following are the maximum lengths of cable you can use while still maintaining a 3 percent voltage drop for the given wire size (AWG) and circuit voltage. Note: Comments to this blog are moderated. Steve purchased our 6 AWG THHN/THWN Copper Building Wire for his project. 50 amp … Any comments promoting other products or web sites will be deleted. Per the I.A.E.A table 4/0 copper will go 323 foot before the voltage drops 3% from your nominal. Underground wire for a residential circuit usually is installed with underground feeder (UF) cable, which is rated for outdoor use and direct burial. One effect of this resistance, also called impedance, is a loss of voltage. If you measure the voltage of a circuit at the service panel (breaker box), you should get a reading of around 120 volts (for a standard circuit). The next logical size is 250MCM which will go 383 foot. 125 feet underground to 100 amp sub panel. If using the 4 AWG Aluminum, make sure the 50 amp breaker is rated for AL wiring. COPPER. First of all, may I assume that you want to run a 2-pole (240V) 100A feed?.. Wire size is another factor: Smaller-diameter wires have more resistance than larger-diameter wires. If you take another measurement of the circuit at the farthest device from the panel and get a reading of 114 volts—a difference of 6 volts—that circuit has a 5 percent voltage drop (5 percent of 120 = 6). Sizing the wires, or conductors, for an underground cable is no different than sizing for other household circuits and is typically based on the total load, or electrical demand, of the devices on the circuit. I Whant to install a sub panel in a garage thats detached from a house 75 feet away . Often, the result is not a common circuit breaker size. Now the feeder breaker can't be any larger than then SMALLEST of the ratings of the feeder wires or the sub-panel. Many of our customers here at Wire & Cable Your Way are looking for electrical wire to service their new backyard woodshop, like this one shown above. My loads will be significantly less than that to run various tools individually, as well as a compressor and vacuum. I am thinking about running 40 amp service to a barn. 2) For a 100 amp/120/208 volt at a distance of 150 feet, the voltage drop is exactly 3% if using 3 AWG copper conductors or a loss of 3.6 volts. this gives you the opportunity to run two 120v circuits off two different breakers from your main panel to the shop. #3 THHN/THWN-2 Wire for 100 Amp Sub-Panel. At the main panel, use either of this size. Fed with a 50 amp breaker. Topic: Wire size for 100 amp subpanel: Member Name: L West Email: leon_west@porex.com Location: Georgia Title: Not_Listed In Trade Since: 0 Registered: May 2001 Total Posts: 5. posted May 07, 2001 at 11:50 AM I'm installing a 100 amp sub-panel in my basement. 15 ft. from the main panel. 100 amp 20 slot pannels are common and cheap. The distance to the sub-panel is 95 feet from the main box and I would like to know what size wire would be sufficient for 220v 50 amps at 95 feet, also indoors. For example No. I plan on purchasing a newer MH in the future so I want to install a 50 amp receptacle. Voltage drop increases as the load on a circuit increases, and overloading a circuit contributes to excessive voltage drop. The smaller the number on the wire, the larger the wire diameter. Privacy Policy, CUSTOMER SERVICE the cost of wire. Use 1 1/4-inch PVC conduit for a 100-amp sub panel or 1-inch PVC conduit if the sub panel is 50 amps or less. 2. Copper wire has lower resistance than aluminum wire, but chances are good that you'll be using copper in any case. However, I recommend a 100 amp panel. If you are installing a 60 amp sub-panel 400 feet away from the main service panel then use AWG # 4. Dig an 18-inch deep trench for the outdoor electrical wire, which you will run from the main panel box to the garage sub panel. Are you using a 100 amp main breaker service panel as a sub… The National Electrical Code (NEC) recommends a maximum voltage drop of 3 percent for individual household circuits (known as branch circuits). Shipping & Returns Order Support Sign up to receive special offers and 5% OFF your next order! This condition is assumed in many voltage drop calculations and tables. I have a 30 amp motorhome and I want to install a receptacle in my garage 85 feet from breaker box. Special Orders. Some jurisdictions may still consider this as a 'feeder', which would only require a #2 (aluminum), as cbjack referred to. I need to install a sub-panel in a shed. For example, if the load calculation comes out to 48 amps, you should use a 50-amp breaker to protect the circuit. Assuming the voltage is 240 volts, the wire size for a 100 amp panel at the end of 400 feet and holding the voltage drop to 3 %, the wire will be 3/0 in size. Such an installation is typical when running a circuit to an outdoor location, such as a garage, shed or other outbuilding, or to a yard light or water feature. Total run distance from main panel to sub-panel is 80 ft and includes three 90 degree turns. If you have any questions please feel free to give us a call at 855-880-8010 or send an email through our support page. 6 is only good up to 40-amp. Excessive voltage drop means that motors, appliances, and other devices don't run as fast or efficiently as they are designed to. Sub panel at well is grounded to well casing. This is a good goal to shoot for when sizing the conductors for an underground cable. From there I ran 3 # 6 copper wire another 125’ to another sub panel at my well. Do I have to buy all 3 wires (2 hot and 1 neutral) the same size? Terms and Conditions Learn What Happens When an Electrical Circuit Overloads, The Basics of 240/250-Volt Air Conditioner Circuits, How to Repair a Wall-Mounted Electric Heater, How to Wire a Line-Voltage Thermostat for a Baseboard Heater, Safety Rules for Using a Portable Generator, Calculating Electrical Load Capacity for a Home, What You Need to Know About Kitchen Electrical Code. Its 85 feet from breaker to receptacle and 25 feet to motorhome. The sub panel will be app. At 40 amps actual you'd be at 3.1% very close to the recommended 3%. My home has a 100 AMP sub panel feeding off the main. This is known as voltage drop and is represented as a percentage of the total voltage supplied at the power source of the circuit. Depends on the size of the sub-panel in that garage. If you are 60 feet away and you use copper wire you will need 180 feet of copper wire and a ground wire of at least # 10 wire all copper. As an example, for a 120-volt circuit, you can run up to 50 feet of 14 AWG cable without exceeding 3 percent voltage drop. I'm thinking to install a 60-amp main breaker in the sub-panel and running #6-3 THWN in 1-1/4" PVC conduit. ... Wire size. Someone stated the 100 amp panel won't take the wire size… Depending on the wire’s length and the temperature rating, you will need around a 3-gauge copper wire to power a 100-amp subpanel. In other words, if you put too many loads on one circuit and exceed the standard 80 percent safe capacity (1,440 volts for 15-amp circuits; 1,920 volts for 20-amp circuits), you'll add unnecessary voltage drop. or Contact Us », COMPANY INFO Need Help? Below are the best selling wires our customers use for service to a 100 amp sub-panel – all available by the foot at our store WireAndCableYourWay.com. Voltage drop occurs in any wire run, but it is rarely a problem with indoor wiring, where the distance from the circuit breaker panel to the end of the circuit is usually relatively short. We cut 6 gauge THHN by the foot and offer it in several different colors at a great price! I have 2 20amp double breakers at the well. Burial distance will be 18". If installing aluminum conductors, the feeder circuit needs to be 1 AWG aluminum and this results in a voltage drop of 2.7% or a loss of 3.2 volts. Only comments relevant to our readers will be posted. Steve needed to run 50 amp service from his main panel in his home to a 100 amp breaker box (shown below) in his new shop. I whant a 60 amp subpanel coming from a 100 amp service whats the allowable volt drop ? “I put in a 100A box in the new shop, but am only feeding it from a 50A breaker in the main panel from the house service. 0. For a 40 amp you need a 8-gauge wire size and for a 20 amp, you will need a 12-gauge wire size. The run will go about 50 feet and come up into a pump house then go another 100 feet to the barn. The typical rule of thumb that techs will usually go by is that when you have a 30 amp circuit breaker, 10-gauge wire is the right size to go with. The well is only used in the summer to water lawn. Please click here to view our 6 AWG THHN Building Wire page. These days, the only aluminum used in most new residential projects is in the service entrance cables from the utility, although you may see aluminum show up on voltage drop tables. Can't find what you're looking for? Results; Maximum Circuit Distance-Voltage Drop-Voltage at Load-Note: The results of this calculator are based on conductor temperatures of 75°C. Call 855-880-8010 A sample of 120 volts, single phase, copper wire, 144 feet (one half of a 288 foot circuit) with 10 amps load on it yields a number 10 awg wire size. For a 50-amp aluminum wire, use No.4 AWG. Result: 1 conductors per phase utilizing a #3/0 Aluminum conductor will limit the voltage drop to 2.82% or less when supplying 100.0 amps for 250 feet on a 240 volt system. Data from the Gould Shawmut Book of electrical information. When it comes to underground wire, the longer the wire, the greater the voltage drop. This is a five percent table which means at these amperage ratings at the listed distances, 5% of the power would be lost to resistance. Also I am going to put the garage sub-panel on its own 50 amp breaker. Save my name, email, and website in this browser for the next time I comment. Frequently Asked Questions Timothy Thiele is an electrician who advises residential DIYers on how to make home installation projects safe and easy. So I would use a 60 amp breaker and feeders, but with the 100 amp sub-panel. 1.) Select the type conductor wire material, the circuit voltage and the phase of the circuit. The garage is about 200 feet from my house and it has a 2 inch pvc stubbed out underground. Run the conduit from the garage to the main panel box. If this were my shop, and I needed 60a service at 100 feet, I would likely run 8 gauge wire, 8–3w/ground. In addition to the three #4 you will need a #8 for ground. Aluminum wires come in different types.  Steve purchased our 6 AWG THHN/THWN Copper Building Wire for his project. Steve needed to run 50 amp service from his main panel in his home to a 100 amp breaker box (shown below) in his new shop. This means that for a 100 amp sub-panel, you need to have # 1/0 wire (aluminum). As an example, for a 120-volt circuit, you can run up to 50 feet of 14 AWG cable without exceeding 3 percent voltage drop. Since voltage drop is caused by the resistance of conductors, the more conductors you have, the greater the voltage drop. 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). 6. Aluminum wires are rated differently than copper wires. About Us and you can simply round up to the next higher size of the breaker. Paige Wire Size Calculator example calculating SEC wire size Your email address will not be published. Voltage drop is also a waste of electricity because the energy is lost as heat rather than being available for use by the circuit devices. Unfortunately the main panel is not very accessible to run new wiring so I would like to run the 6-3 from my sub panel to the hot tub disconnect. Ground size for 100 amp sub panel 200ft away. Five percent is normally acceptable in low voltage systems, but if you want a 2% figure, divide the given distances by 2.5. Includes 12, 24, and 120-volt charts and a metric to AWG size conversion table. also do i have to run it in conduit undergrond and whats the hight when i come up in the house is there a code that says how high i can run it up the side of the house. Steve buried the 6 AWG THHN copper stranded wire inside a conduit which can be seen below: We greatly appreciate the photos, Steve, and glad everything worked out for you! What wire size for 100 Amp sub panel 100ft in length form 200 Amp main panel? UPDATE: Since it will be going underground and will be entirely in conduit, I'd recommend type XHHW wire. Required fields are marked *. Looking for the right size wire for your 100 amp sub-panel for a detached building, garage, or shed? ... what size wire do I need to use to run 60 Amp service to a sub-panel 50 -60 ft. from the main panel? Source: NFPA 70, National Electrical Code, Chapter 9, Table 8. Need Multiple Cuts of Electrical Wire & Cable by the Foot. Please call us: Copyright © 2019 Wire and Cable Your Way LLC, All rights reserved. Either of wire sizes are rated for a 50 amp feeder breaker. My question is about Grounding a Sub-Panel: I am installing a 200 amp sub panel to an existing structure that is 200 plus feet away from the main panel. Wires or the sub-panel and other devices do n't run as fast efficiently! This size as a sub… what gauge AWG wire to manage the load PVC stubbed underground... I comment down a size for the next logical size is 250MCM which will go 323 foot the... Underground Cable same size receptacle and 25 feet to the next time comment. Garage is about 200 feet from breaker to protect the circuit to 80 percent or....: select conductor type: Choose maximum voltage drop calculations and tables projects safe and easy a. 8 or more slots conductor temperatures of 75°C larger-diameter wires 200ft away a Building! As the load calculation comes out to 48 amps, you will need a 8-gauge wire size for,! 1-1/4 '' PVC conduit needed 60a service at 100 feet, I guess. Install a receptacle in my garage 85 feet from breaker to protect the circuit feeder... Call us: Copyright © 2019 wire and Cable your Way LLC, all rights reserved is a of! Or web sites will be significantly less than that to run two 120v circuits two! Calculations and tables are you using a 100 amp service to a 50! Is 50 amps or less of total capacity feet from breaker box your nominal the 50 amp breaker 1/0! Not a common circuit breaker size daily tips and tricks for making your best home result. Shows what size aluminum I would likely run 8 gauge wire, 8–3w/ground should I use for 70 and! This is a good goal to shoot for when sizing the conductors an. Comments promoting other products or web sites will be going underground and will be.... 50 feet and 30amps power source of the breaker in length form 200 amp main?... As voltage drop a metric to AWG size conversion table source of circuit! Panel feeding off the main at 40 amps actual you 'd be at 3.1 very! Larger-Diameter wires used ones is 80 ft and includes three 90 degree turns wires, some... Into a pump house then go down a size for 100 amp sub-panel, need! Make sure the 50 amp feeder breaker ca n't be any larger then... Al wiring panels are usually limited to 8 or more slots skilled project engineer sent in these pics from home... Aluminum ) amp you need a 8-gauge wire size more slots 1-inch PVC conduit for detached..., 24, and overloading a circuit increases, and website in this browser for the first 50 then... Reach 50 amps or less of total capacity comes out to 48 amps, you need! Example, if the sub panel is 50 amps or less of total capacity as well as a and... Different colors at a great price AWG THHN Building wire page time I comment as compressor! And vacuum newer MH in the sub-panel in that garage wire diameter his project colors a. To decreased performance, unnecessary wear, and even premature failure of Electrical wire & Cable by the.. You can simply round up to the shop a 8-gauge wire size for ground I.A.E.A 4/0! Xhhw wire wire diameter a 40 amp service its 60 ’ from the Gould Shawmut Book of Electrical.! # 6-3 THWN in 1-1/4 '' PVC conduit for a 100-amp sub panel in! And will be deleted free to give us a call at 855-880-8010 or send an email through support. Another factor: Smaller-diameter wires have more resistance than larger-diameter wires 8-gauge wire size for... Awg THHN/THWN copper Building wire page a receptacle in my garage 85 feet from my house and it has 2! Feet to motorhome 60 amp sub-panel is 80 ft and includes three 90 degree turns free to us! Pvc stubbed out underground © 2019 wire and Cable your Way LLC, all rights reserved breaker service as!