Replies

1. 
   dukeone | Feb 19, 2005 02:33am | #1

   Type of breaker: to match existing panel
   Size of breaker: to match requirement of equipment
   Size of wire: to match breaker or larger for long run
   Most dangerous part of job: installing breaker
   All else depends on type of wall, local codes and installers skill. Is there room in panel and is there electrical capacity to handle saw?
   KDM, electrician, thirty years, neo-woodworker two years and counting

1. 
   Jellyrug | Feb 19, 2005 03:40am | #3

   "Type of breaker: to match existing panel"

   Correct.

   "Size of breaker: to match requirement of equipment"

   Suggest a 40Amp breaker, as this will not match requirement of equipment, but rather the sub board, allowing for future expansion.

   "Size of wire: to match breaker or larger for long run"

   #8 with four wires, being two hot, one neutral and one ground.

   Followed by a sub board with space for six single pole, or three double pole breakers.

   Followed by a 20 Amp breaker, assuming the saw is under 5hp and supplying a 240v NEMA style 6-20 receptacle with #12, or #10 wire if the run is more than 100ft..

   "Most dangerous part of job: installing breaker"

   Crawling around in the attic, without falling through the roof.

   "All else depends on type of wall, local codes and installers skill. Is there room in panel and is there electrical capacity to handle"

   Agree

   If you are doing this yourself, OK provided you have done electrical work before, suggest you consult with someone who is licienced in your state, in person, before starting and to check after completion.

   W. J. Martins BS Mechanical Engineering 1979, MS Electrical Engineering 1983, Registered Pr. Engineer Europe, Registered Engineer California state.

1. 
   TomMGTC | Feb 19, 2005 04:11am | #4

   What is the purpose of running the four wire conductor for a 230v saw. Unless he has 110v controls which is highly unlikely the neutral will never be used. I have at least 7 dedicated 220v circuits and none are 4 wire.Tom

   Douglasville, GA

1. 
   dukeone | Feb 19, 2005 05:05am | #5

   In this case four wires would be for a sub-panel. Any 220 or higher voltage machine with lower voltage controls would use a control transformer with one side of the secondary grounded.
   KDM

2. 
   Jellyrug | Feb 19, 2005 05:06am | #6

   The purpose of running four wires to the sub board is to satisfy NEC rules, as ground and neutral has to be separate.

   Running three wires to a receptacle and running four wires to a sub board are two different things.

1. 
   dukeone | Feb 19, 2005 05:09am | #7

   Unless the subpanel is in a separate building in which case the neutral and ground are together (grounding conductor, not grounded conductor) and it would separate in the new panel with a new ground rod installed. KDM

2. 
   TomMGTC | Feb 19, 2005 05:18am | #8

   OK, I'm with you now. I didn't read your reply closely enough. Looked to me like he only was adding a circuit for a saw. Seems like a subpanel maybe overkill for what  the original poster was asking.Tom

   Douglasville, GA

3. 
   Jellyrug | Feb 19, 2005 05:33am | #9

   You are right, could be an overkill, I wrongly understood his comment "wiring the box" as a separate board. But then again he talks about breakers, more than one?

   It's dangerous giving electrical advice in this forum as I won't encourage anyone without good experience to do this work by themselves. I believe you need 14 milli amps through the heart, it stops and its goodbye. The rules here in the US are very easy, in Europe qualified means a formal apprenticeship and a test passed afterwards by a recognized institution, followed by an installation licence. Some countries mandate city inspections after any residential work, and the electrical work must be performed by someone with a licence.

   Edited 2/18/2005 9:40 pm ET by Jellyrug

   Edited 2/18/2005 10:05 pm ET by Jellyrug

2. 
   damschrs | Feb 19, 2005 03:39am | #2

   Give Duke your specs for your saw and he'll give you the appropriate advice to get it done correctly and safely. You won't get better advice.
   scottd.

    

   scottd
   Damschroder Scott Furniture
   [email protected]

   A craftsman needs three things: Accuracy, Technique, and Quality. Accuracy can be set; technique can be learned; but quality must be bought and built.

3. 
   AlbionWood | Feb 19, 2005 08:11am | #10

   For some reason everyone is talking about adding a subpanel, but if I read you correctly, all you need to do is add a circuit to an existing panel. For that you need to know the amperage of the motor (look on the plate) in order to get the correct size breaker and wire. Once you have that, the wiring is really pretty simple, and adding the breaker is really easy. Just remember to turn off the main breaker supplying power to the panel, before doing anything inside it!

   Having said that, it would be better if you could get a friend who has done this before to help you. If you get the wires crossed you can get some spectacularly bad results.

   "Everything should be made as simple as possible, but no simpler."  A. Einstein

   http://www.albionworks.net

1. 
   wrudiger | Feb 19, 2005 06:35pm | #11

   I agree with both points of view.  All I needed to do was "just run the circuit for the saw" as well - no problem.  Then I got the DC, then the jointer, then...  Wish I'd run the subpanel to start with!!