Replies

1. 
   IronHelix | Dec 31, 2003 03:08pm | #1

   Just some local sequences, not any calculated loads, or use of electrical tables.

   Your last comment about a welder puts you into a 100 amp box and a 100amp service over a distance of 150 ft....which translates to a minimum underground service wire size of 2/0 aluminum.  

   I would want to have someone calculate voltage drop on the 150 ft line with a 50 amp welder buzzzing away to make sure that a 3/0 aluminum URg was not needed.

   Someone with stats will come along and give us the technical scooop!

   Happy Welding!

   ....................Iron Helix

1. 
   brownbagg | Dec 31, 2003 03:37pm | #2

   go ahead with 100 amp. its really not that much more, couple dollars. You will need it later. if you get a bigger compressor or if you add heat or window unit.

   for electrical question go to http://www.doityourself.com electrical section, talk to Nelson. He's the master on these question

   The best employee you can have but you wouldn't want him as a neighbor " He the shifty type"

1. 
   Dawg | Dec 31, 2003 04:53pm | #4

   I would prefer to use copper for this. I dont really want to wrestle 2/0 if I can help it.

1. 
   riprock | Dec 31, 2003 10:51pm | #5

   Here's an online calculator

   http://elec-toolbox.com/calculators/voltdrop.htm

2. 
   rjgogo | Jan 01, 2004 02:23am | #6

   "Your last comment about a welder puts you into a 100 amp box and a 100amp service over a distance of 150 ft....which translates to a minimum underground service wire size of 2/0 aluminum."

   Not True,  I have two pretty capable welders,  One only draws a little over 20amps 220 at full output,  the other draws less then 40AMPs I think at full output and I don't think I have ever run it at full output.  One is a Millermatic 175 Mig and the other is a Lincoln tombstone AC/DC stick,   I have a 60 Amp sub panel in my garage and I have never had a problem. The lights don't dim when welding with either welder.  I have had every light on and two kerosene heaters running while welding and not skipped a beat.

      Not saying 100amp would not be good but unless there are going to be multilple users I doubt you would ever need it.  Remember unless you are running those welders wide open they draw much less then the top rating.  The table saw is 15amp 110,  you can rewire for 220 but the amps required  go down. 

   As long as you size the wire right for the voltage drop over the distance you will be fine. 

1. 
   Dawg | Jan 01, 2004 05:01am | #7

   But can anyone tell me what size copper wire I need to feed this shop, even for 100 amp service?

1. 
   rjgogo | Jan 01, 2004 06:58am | #8

   Book I have states that 1/0 copper is good, voltage drop wise, to 230 feet for 240 volts at 100 amps, size goes way down if you go to 60 amps. Weigh the options.

   Make sure you get the installation right regarding neutrals, grounds and bonding, otherwise you could have issues, plenty of posts on that to search through. I am not an expert so I will leave it up to you to look it up. Besides I have to do most everything in steel conduit where I live and it differs a bit from the other methods.

2. 
   IronHelix | Jan 01, 2004 06:59am | #9

   Most stick welders are set up for a 50 amp plug and breaker....wire accordingly!  Even if you rarely crank it up....extended use @medium amperage but at 80% duty will heat the wire and pop the breaker.....  

   I have a tomstone AC/DC that on rare occassion has to infill a chamfered set of 1/2"plate overlaps or butt connections......the heavy duty cycle will pop the 50A Breaker.  Plan for the heaviest use when you wire an appliance/tool.

   Calculate loads according to mfg specs, wire to meet those specs....Be Safe!

   ..............Iron Helix

1. 
   rjgogo | Jan 01, 2004 07:16am | #10

   I have mine on a 50 amp plug and breaker but never poped it. I think I did use it wide open once or twice and it never tripped the breaker, but not for an extended period of time, but I have it over wired. Running 6 from the sub panel to the plug and that is only about 3 feet, still if it pulled more then 50 it would have tripped. My extension cord is made out of 6 as well. It was free. I could have used 8 I think.

   Edit to add, If I could figure out a way to hit a 80% duty cycle I would love it , I have to stop to often to grind, fit up, clean, etc. If you can be burning 8 out of every 10 minutes, you must have spent some time on prep.

   Edited 12/31/2003 11:20:37 PM ET by rjgogo

2. 
   BillHartmann | Jan 01, 2004 04:50pm | #11

   Dedicated motor and welding circuits have special rules that don't follow the normal rules. At least for motor circuits you can upsize the breakers larger than that based on just the wire size. Have not followed through all of the details in the welding specs to figure out exactly how it works.

1. 
   cameraman | Jan 02, 2004 03:43am | #12

   I know this maybe off on a tangent but in my basement workshop is acessable to my small children so I took procautions. Wired a dissconnect that handled all recept. that serviced power tools. Bench and floor type tools that would normally be left plugged in. Kept recept. that serviced rechargable batteries and lighting alone and the dissconnect was high on the wall next to the exit door. Just had a fear that my 9yr old would come down and be like dad and flip on the switch for the 10" radial. Just a thought of saftey.

   Remember count your fingers before and after every cut, saves time sifting threw the sawdust!

2. 
   rasconc | Jan 02, 2004 07:26am | #13

   Great idea!  Grandkids will be down in mine sometime.  Just getting ready to wire up and had not thought about that.

2. 
   CJD | Dec 31, 2003 04:51pm | #3

   With a table saw, you may add a dust collector. An air compressor may automatically start while running the table saw.