Go Back  DoItYourself.com Community Forums > Electrical, AC & DC. Electronic Equipment and Computers > Electrical - AC & DC
Reload this Page >

Do I need a 6-3 copper romex cable for a heater and table saw?

Do I need a 6-3 copper romex cable for a heater and table saw?

Reply

  #1  
Old 03-14-17, 10:45 AM
C
Member
Thread Starter
Join Date: Jul 2010
Location: USA
Posts: 959
Received 0 Votes on 0 Posts
Do I need a 6-3 copper romex cable for a heater and table saw?

I'm requesting a quote for running electrical cable from my breaker to my garage for a heater and a table saw. One of the service I've contacted for estimates wants to use the following material.

150 fett 6-3 copper romex, 1-2 pole 40 amp cutler ch breaker, straps, romex and flex connectors, 3 feet of flex conduit, 1- 60 amp disconnect for heater, 1-gang j-box

The heater I have is, Fahrenheat FUH54 240-volt Garage Heater, 2500-5000-watt. The table saw I'm looking at purchasing is the SawStop PCS31230-TGP252 3-HP Professional Cabinet Saw. The guy wants to run two cables indepently so that once I use the table, it would not trigger the heater to shut off. Am I wrong that 6 gauge is a better overkill for a heater and a table saw?
 
  #2  
Old 03-14-17, 11:26 AM
S
Group Moderator
Join Date: Oct 2004
Location: WI/MN
Posts: 19,609
Received 97 Votes on 85 Posts
Attached or detached garage?
 
  #3  
Old 03-14-17, 11:35 AM
C
Member
Thread Starter
Join Date: Jul 2010
Location: USA
Posts: 959
Received 0 Votes on 0 Posts
Attached garage. I have drop ceilings in my basement so I could potentially wire it myself but I'm curious as to is it necessary to use a 6-3 romex cable. Would an 8-3 do the job if I'm running two independent cable.
 
  #4  
Old 03-14-17, 11:56 AM
PJmax's Avatar
Group Moderator
Join Date: Oct 2012
Location: Northern NJ - USA
Posts: 60,874
Received 1,342 Votes on 1,240 Posts
Your heater would draw 21A @ 240v. For that alone you could use 8-2 w/g NM-b on a 30A breaker.

You could probably use 6-3 w/g NM-b to feed a sub panel in the garage and then run both.
You'd have a 2P 50A or 60A breaker at the main panel.
A 2P30 for the heater and a 2P20 for the 13A @ 240v table saw.

If the sub panel is in the garage within sight of the heater then no disconnect is needed.
 
  #5  
Old 03-14-17, 11:57 AM
I
Forum Topic Moderator
Join Date: Feb 2005
Location: Near Lansing, Michigan
Posts: 10,943
Received 44 Votes on 42 Posts
It is a reasonable choice to upsize the cable to #6 for the heater given the 150' distance. Less than 100' length #8 would be acceptable.
 
  #6  
Old 03-14-17, 12:26 PM
C
Member
Thread Starter
Join Date: Jul 2010
Location: USA
Posts: 959
Received 0 Votes on 0 Posts
Thank you so much for the responses. I'd appreciated.
 
  #7  
Old 03-14-17, 12:45 PM
P
Member
Join Date: Feb 2016
Location: United States, Virginia
Posts: 1,513
Received 125 Votes on 99 Posts
You'd be a lot better off $$ wise running 2-2-2-4 Al SER from the main panel off a 60A DP breaker to a subpanel in the garage.
 
  #8  
Old 03-14-17, 05:31 PM
Tolyn Ironhand's Avatar
Group Moderator
Join Date: Nov 2007
Location: United States
Posts: 13,806
Received 253 Votes on 221 Posts
I would also agree with Pjmax and install a sub panel in the garage. 6-3 with ground would be fine on a 60 amp breaker. #2 AL is overkill, but would still work.
 
  #9  
Old 03-14-17, 05:45 PM
P
Member
Join Date: Feb 2016
Location: United States, Virginia
Posts: 1,513
Received 125 Votes on 99 Posts
#2/3 AL SER is not overkill for 60A at 150'. It will cost less than half of 6/3 Cu. Could probably get by with 4/3 AL SER for even less $$.
 
  #10  
Old 03-14-17, 07:45 PM
Tolyn Ironhand's Avatar
Group Moderator
Join Date: Nov 2007
Location: United States
Posts: 13,806
Received 253 Votes on 221 Posts
#2 AL is rated for 75 amps, 60 degree column so it could be put on an 80 amp breaker. #4 Al is rated for 55 amps, 60 degree column, so it is good for 60 amp breaker. Voltage drop is not a real issue at 150'
 
  #11  
Old 03-14-17, 07:48 PM
C
Member
Thread Starter
Join Date: Jul 2010
Location: USA
Posts: 959
Received 0 Votes on 0 Posts
Thank you, guys. I will gather this information and propose it to a licensed electrician and see how much he'll charge. If it's reasonable, I may go that route, if not, I'll purchase the material and run the wire myself and just hire a license electrician to install the sub panel and connections to my breaker in the basement.

Pattenp, is this something you
 
  #12  
Old 03-14-17, 07:52 PM
C
Member
Thread Starter
Join Date: Jul 2010
Location: USA
Posts: 959
Received 0 Votes on 0 Posts
Here's another one I found.
 
  #13  
Old 03-15-17, 07:53 AM
P
Member
Join Date: Feb 2016
Location: United States, Virginia
Posts: 1,513
Received 125 Votes on 99 Posts
Tolyn Ironhand
#2 AL is rated for 75 amps, 60 degree column so it could be put on an 80 amp breaker. #4 Al is rated for 55 amps, 60 degree column, so it is good for 60 amp breaker.
Actually SER can be used at 75 degree C so #2 is 90A and #4 is 65A. The 60 deg.C is only used if SER is run within insulation. So the #4 Al SER should be plenty as long as it's not buried in insulation.

Edit: As a side note the #4 Al at a load of 60A @ 240V @ 150' will be 3.7%. #2 @ the same is 2.3%. The recommended max VD for a feeder is 3%, this is why I first suggested the #2 Al.
 

Last edited by pattenp; 03-15-17 at 08:11 AM.
  #14  
Old 03-15-17, 07:56 AM
P
Member
Join Date: Feb 2016
Location: United States, Virginia
Posts: 1,513
Received 125 Votes on 99 Posts
The #3 Cu SER is good for 100A, that's a bit much for your needs, plus with the cost of copper. The aluminum Dyke URD is for outside power distribution and is not allowed inside.

If the run is all inside I'd use this...https://www.wireandcableyourway.com/...ding-wire.html

The install method is the same as NM.
 
 

Thread Tools
Search this Thread
 
Ask a Question
Question Title:
Description:
Your question will be posted in: