GlennWest Posted January 5, 2021 Report Share Posted January 5, 2021 (edited) As we know our 50 amp cord is #6. To move my current utility pole will be in the thousands. If use current location, need taller post is all, very little cost. Extend mast and hook up down payment. But need to run my 50 amp service app 300 feet. So any idea what size I need. #1 would give me .7% drop. Edited January 5, 2021 by GlennWest Quote 2003 Teton Grand Freedom towed with 2006 Freightliner Century 120 across the beautiful USA welding pipe.https://photos.app.goo.gl/O32ZjgzSzgK7LAyt1 Link to comment Share on other sites More sharing options...
Chalkie Posted January 5, 2021 Report Share Posted January 5, 2021 44 minutes ago, GlennWest said: As we know our 50 amp cord is #6. To move my current utility pole will be in the thousands. If use current location, need taller post is all, very little cost. Extend mast and hook up down payment. But need to run my 50 amp service app 300 feet. So any idea what size I need. #1 would give me .7% drop. I am not sure I understand your question and will admit I am not an electrician. If you could clarify a bit I will pose the question to my son who is a licensed electrician. Quote Link to comment Share on other sites More sharing options...
Dutch_12078 Posted January 5, 2021 Report Share Posted January 5, 2021 (edited) This calculator says you need #3 AWG wire for a 300 ft run with an allowable 3% voltage drop. The items I input were 240 source voltage, single-phase, 50 amp, 300 ft, 3% drop. http://www.paigewire.com/pumpWireCalc.aspx Edited January 5, 2021 by Dutch_12078 Quote Dutch 2001 GBM Landau 34' Class A F-53 Chassis, Triton V10, TST TPMS 2011 Toyota RAV4 4WD/Remco pump ReadyBrute Elite tow bar/brake system Link to comment Share on other sites More sharing options...
Dutch_12078 Posted January 5, 2021 Report Share Posted January 5, 2021 (edited) Posted in error... Edited January 5, 2021 by Dutch_12078 Quote Dutch 2001 GBM Landau 34' Class A F-53 Chassis, Triton V10, TST TPMS 2011 Toyota RAV4 4WD/Remco pump ReadyBrute Elite tow bar/brake system Link to comment Share on other sites More sharing options...
Jaydrvr Posted January 5, 2021 Report Share Posted January 5, 2021 1 hour ago, GlennWest said: As we know our 50 amp cord is #6. To move my current utility pole will be in the thousands. If use current location, need taller post is all, very little cost. Extend mast and hook up down payment. But need to run my 50 amp service app 300 feet. So any idea what size I need. I assumed with 50 amp you're planning a 120 volt system? That calculates out to 1 awg when using copper. That yields 3.10% voltage drop, which is decent. Jay Quote Link to comment Share on other sites More sharing options...
GlennWest Posted January 5, 2021 Author Report Share Posted January 5, 2021 (edited) 7 minutes ago, Jaydrvr said: I assumed with 50 amp you're planning a 120 volt system? That calculates out to 1 awg when using copper. That yields 3.10% voltage drop, which is decent. Jay 2 legs 120v. Also not finding direct buriable in the size. What calculator you using? I was on Calulator.net and it shows 1.23% drop with #1 copper, aluminum 1.94% Edited January 5, 2021 by GlennWest Quote 2003 Teton Grand Freedom towed with 2006 Freightliner Century 120 across the beautiful USA welding pipe.https://photos.app.goo.gl/O32ZjgzSzgK7LAyt1 Link to comment Share on other sites More sharing options...
Dutch_12078 Posted January 5, 2021 Report Share Posted January 5, 2021 It's a 120/240 service with two hot legs and a neutral leg. Hot leg to hot leg is 240 volts, hot leg to neutral is 120 volts. Quote Dutch 2001 GBM Landau 34' Class A F-53 Chassis, Triton V10, TST TPMS 2011 Toyota RAV4 4WD/Remco pump ReadyBrute Elite tow bar/brake system Link to comment Share on other sites More sharing options...
oldjohnt Posted January 5, 2021 Report Share Posted January 5, 2021 Glenn, here is one among a ton of Voltage Drop Calculators (found on web, NOT my chart, no warranty if its accurate) for you to try. You just plug in the numbers and the answer pops right out. Even if it indicated #1 might suffice for the voltage drop you are willing to tolerate (but I don't like much over 2%) Id probably opt for 0 or better yet 00 (bigger cable = less line voltage drop ) and/or what bulk length sizes are available in your area IE say for example they may only stock 1 or 0 ??? A 50 Amp 4 wire RV Service consists of two Ungrounded (Hot) Conductors (typically Red & Black),,,,,,,One GrounDED (Neutral) Conductor (typically White) ,,,,,,,,,,,One Safety Equipment GroundING Conductor. There would be 240 VAC L1 to L2, but 1/2 half that or 120 VAC from EITHER Line to Neutral. Voltage Drop Calculator 300Feet,,50 Amps,,3.72 Volt drop,,3.1% EXAMPLE ONLY NOT INTENDED AS ACCURATE Some among other options may (if available for your needs ??????) include Underground Service Entrance Cable (USE),,,,,,,,,,,,,Direct Burial Rated Underground Feeder (only if available in your size) Single THWN Conductors enclosed in buried conduit. I prefer copper myself. Your money,, your voltage drop limits,, YOUR choice. Use the chart do your homework and shop around.. John T Quote Link to comment Share on other sites More sharing options...
GlennWest Posted January 5, 2021 Author Report Share Posted January 5, 2021 (edited) That is the calculator I was using. Boy really adds up in runs that long. That probably exsplains lower volts in rv parks. Edited January 5, 2021 by GlennWest Quote 2003 Teton Grand Freedom towed with 2006 Freightliner Century 120 across the beautiful USA welding pipe.https://photos.app.goo.gl/O32ZjgzSzgK7LAyt1 Link to comment Share on other sites More sharing options...
57becky Posted January 5, 2021 Report Share Posted January 5, 2021 If you go with something like this, you will be good. Rarely will you see full 50 amps for each leg so your voltage drop will not be that much. You can get by with 2" conduit, but maybe a little larger would make pulling in the cable easier along with some cable lube. I would recommend terminating the cable in a splice box at each end above ground so you won't have to worry about water getting to the splices or connector lugs. https://ewcswire.com/1-0-1-0-1-0-2-awg-aluminum-ud-quadraplex-600-volts-code-notre-dame/ Quote Link to comment Share on other sites More sharing options...
Wrknrvr Posted January 5, 2021 Report Share Posted January 5, 2021 I am curious as if the incoming power is at or above 120 volts on each leg, would that give you more cushion for wire size. Or if it is down towards 110 volts on each leg then that may make a bigger size more of a must. Possibly test power when it is being used the most. As in early evening when other people on the same power line have gotten home from work and using energy on the same electric system. And test voltage when you are using heavy demand. Arm chair thinking as I am recuperating from a fall on ice a week ago. yep I had a stupid fall, bad idea, Vern in a T-shirt Quote Link to comment Share on other sites More sharing options...
GlennWest Posted January 5, 2021 Author Report Share Posted January 5, 2021 12 hours ago, 57becky said: If you go with something like this, you will be good. Rarely will you see full 50 amps for each leg so your voltage drop will not be that much. You can get by with 2" conduit, but maybe a little larger would make pulling in the cable easier along with some cable lube. I would recommend terminating the cable in a splice box at each end above ground so you won't have to worry about water getting to the splices or connector lugs. https://ewcswire.com/1-0-1-0-1-0-2-awg-aluminum-ud-quadraplex-600-volts-code-notre-dame/ Thank you. Quote 2003 Teton Grand Freedom towed with 2006 Freightliner Century 120 across the beautiful USA welding pipe.https://photos.app.goo.gl/O32ZjgzSzgK7LAyt1 Link to comment Share on other sites More sharing options...
oldjohnt Posted January 5, 2021 Report Share Posted January 5, 2021 1 hour ago, GlennWest said: I would recommend terminating the cable in a splice box at each end above ground so you won't have to worry about water getting to the splices or connector lugs. Yo Glenn, (to add a bit to the good info above) once you decide on the voltage drop (bigger wire = less voltage drop period) you are willing to accept and select (copper or aluminum, I prefer copper) and size the wire accordingly, and say you choose to use underground conduit WHEN I LAST PRACTICED POWER DISTRIBUTION (may have changed since then no warranty) where the conduit rose up out of the ground I SPECIFIED RIGID CONDUIT The voltage drop and wire size, can only be calculated once you determine YOUR ACTUAL CURRENT LOAD. This is an area I do NOT like to guess at but, if in doubt I tend to over engineer oversize and reduce line voltage drop as much as reasonably possible to protect and better serve your equipment, especially AC units. Do your homework, calculate the current, select the proper wire size to allow for the max current PLUS UPGRADES and allowable line voltage drop YOU GOT THIS... PS My design per the NEC when I last practiced (no warranty may have since changed) was to compute the Maximum Continuous Current,,,,,,Size the conductors to have a minimum ampacity of 125% of the MCC,,,,,,,,Calculate Voltage Drop and increase wire size if necessary. John T Quote Link to comment Share on other sites More sharing options...
GlennWest Posted January 5, 2021 Author Report Share Posted January 5, 2021 John, been watching our power usage for over a year now. Using our surge protector read out. Most I have ever seen is 60 amps combined legs. Most on a single leg 30ish. This only during cooking with electric. So I likely never need 50 amps each leg. I wouldn't want voltage to drop a lot though Quote 2003 Teton Grand Freedom towed with 2006 Freightliner Century 120 across the beautiful USA welding pipe.https://photos.app.goo.gl/O32ZjgzSzgK7LAyt1 Link to comment Share on other sites More sharing options...
RandyA Posted January 5, 2021 Report Share Posted January 5, 2021 (edited) Reply redundant - sorry - deleted. Edited January 5, 2021 by RandyA Quote Randy, Nancy and Oscar "The Great White" - 2004 Volvo VNL670, D12, 10-speed, converted to single axle pulling a Keystone Cambridge 5th wheel, 40', 4 slides and about 19,000# with empty tanks. ARS - WB4BZX, Electrical Engineer, Master Electrician, D.Ed., Professor Emeritus - Happily Retired! Link to comment Share on other sites More sharing options...
oldjohnt Posted January 5, 2021 Report Share Posted January 5, 2021 (edited) 1 hour ago, GlennWest said: Most on a single leg 30ish. Thanks for the data Glenn, good job. Sure if the Maximum Continuous Current (MCC) is less then 50 Amps you can now size the wire accordingly (based on current, distance and and wire type) but my professional (albeit long retired) advice is still use the NEC guidelines (see my post above, minimum ampacity 125% of MCC) to compute the wire size, then the Voltage Drop Calculator to see if an oversize is required to reduce voltage drop, then allow a bit extra for safety and expansion, and you're good to go. YOU GOT THIS PS I have described how to design this per the NEC as I last practiced it. HOWEVER that being said, if I were to install a 50 Amp RV Service I would design it to have the capacity to deliver a full true 50 Amps at an acceptable voltage. IE If installing a 50 Amp RV outlet Id use 50 even if 30 is your expected max current !!!!!!!! I would NOT install a 50 amp RV outlet that was designed to handle (at acceptable voltage drop) ONLY 30 Amps Now its YOUR choice not ours John T Edited January 5, 2021 by oldjohnt Quote Link to comment Share on other sites More sharing options...
GlennWest Posted January 5, 2021 Author Report Share Posted January 5, 2021 (edited) Stepped it off and came up with 200'. And with a little cleaning I can cut some from that. So #1 copper gives me 2.07% drop. Edited January 5, 2021 by GlennWest Quote 2003 Teton Grand Freedom towed with 2006 Freightliner Century 120 across the beautiful USA welding pipe.https://photos.app.goo.gl/O32ZjgzSzgK7LAyt1 Link to comment Share on other sites More sharing options...
Darryl&Rita Posted January 5, 2021 Report Share Posted January 5, 2021 1 hour ago, GlennWest said: John, been watching our power usage for over a year now. Using our surge protector read out. Most I have ever seen is 60 amps combined legs. Most on a single leg 30ish. This only during cooking with electric. So I likely never need 50 amps each leg. I wouldn't want voltage to drop a lot though Don't be that guy. Build it right. The extra expense in the first install is minor compared to replacing to make it right. Quote I have been wrong before, I'll probably be wrong again. 2000 Kenworth T 2000 w/N-14 and 10 speed Gen1 Autoshift, deck built by Star Fabrication 2006 smart fourtwo cdi cabriolet 2007 32.5' Fleetwood QuantumPlease e-mail us here. Link to comment Share on other sites More sharing options...
GlennWest Posted January 5, 2021 Author Report Share Posted January 5, 2021 16 minutes ago, Darryl&Rita said: Don't be that guy. Build it right. The extra expense in the first install is minor compared to replacing to make it right. Don't understand your comment. I was just stating our power usage. It is lower than most due to our mini splits. I have a 200 amp service. If I need more I can always put a small building at the pole. Not limiting anything. Quote 2003 Teton Grand Freedom towed with 2006 Freightliner Century 120 across the beautiful USA welding pipe.https://photos.app.goo.gl/O32ZjgzSzgK7LAyt1 Link to comment Share on other sites More sharing options...
Jaydrvr Posted January 5, 2021 Report Share Posted January 5, 2021 54 minutes ago, GlennWest said: Don't understand your comment. I was just stating our power usage. It is lower than most due to our mini splits. I have a 200 amp service. If I need more I can always put a small building at the pole. Not limiting anything. He's just saying it's a lot easier to put larger gauge wire in now, than to come back later and dig it all up to swap it out. I agree. Cheap insurance. Jay Quote Link to comment Share on other sites More sharing options...
GlennWest Posted January 5, 2021 Author Report Share Posted January 5, 2021 57 minutes ago, Jaydrvr said: He's just saying it's a lot easier to put larger gauge wire in now, than to come back later and dig it all up to swap it out. I agree. Cheap insurance. Jay My camper can only use 50 amp period. Take a complete rewire to take more. Again I don't see where I can even use more. If I put a shop on property I will come off of the 200 amp pole. Quote 2003 Teton Grand Freedom towed with 2006 Freightliner Century 120 across the beautiful USA welding pipe.https://photos.app.goo.gl/O32ZjgzSzgK7LAyt1 Link to comment Share on other sites More sharing options...
Lou Schneider Posted January 5, 2021 Report Share Posted January 5, 2021 Another alternative is to use smaller gauge wire that has the ampacity to handle the load and ignore the long distance voltage drop, i.e. #6 or larger foir 50 amps. Then put something like a Hughes Autoformer at the load end to boost the voltage back to normal. I haven't priced wire lately so I don't know if this would save anything vs. just using larger wire. Quote Link to comment Share on other sites More sharing options...
GlennWest Posted January 5, 2021 Author Report Share Posted January 5, 2021 (edited) Hadn't thought of the auto former. With #1 copper, I will have little loss. If I ran #6 I would have a 8 volt loss. At what loss will appliances suffer? Edited January 5, 2021 by GlennWest Quote 2003 Teton Grand Freedom towed with 2006 Freightliner Century 120 across the beautiful USA welding pipe.https://photos.app.goo.gl/O32ZjgzSzgK7LAyt1 Link to comment Share on other sites More sharing options...
Jaydrvr Posted January 5, 2021 Report Share Posted January 5, 2021 22 minutes ago, GlennWest said: Hadn't thought of the auto former. With #1 copper, I will have little loss. If I ran #6 I would have a 8 volt loss. At what loss will appliances suffer? You only run into the voltage drop at maximum amperage draw. How often does that happen? Some appliances will suffer shorter life, some don't really care. Jay Quote Link to comment Share on other sites More sharing options...
GlennWest Posted January 5, 2021 Author Report Share Posted January 5, 2021 Ok then. Have not pulled but max 30ish amps for a year on either leg. I might add a 30 gallon hot water heater if mine fails. I will likely run #1 copper. Just have to run conduit with that size. Can get #6 direct burial Quote 2003 Teton Grand Freedom towed with 2006 Freightliner Century 120 across the beautiful USA welding pipe.https://photos.app.goo.gl/O32ZjgzSzgK7LAyt1 Link to comment Share on other sites More sharing options...
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