question regarding voltage loss calculator

Reply

  #1  
Old 01-07-07, 01:17 PM
S
Member
Thread Starter
Join Date: Oct 2004
Location: USA
Posts: 33
Received 0 Votes on 0 Posts
question regarding voltage loss calculator

What is the largest double pole breaker I can use on 10 gauge bx with a 1/2 circuit length of 38ft? I want to reuse my old hot water heater line for a sub panel to feed my basement, which I am finishing. I found a calculator online but i was confused as to whether to specify 240 or 120 for voltage. Currently it's hooked up to a 30amp dbl pole breaker. Is that already the max?
thks
 
Sponsored Links
  #2  
Old 01-07-07, 01:20 PM
J
Member
Join Date: Apr 2006
Location: New Bern, NC
Posts: 1,623
Received 0 Votes on 0 Posts
You are doing this backwards. First calculate the load, then the wire and breaker.

no. 10 is limited to 30 amps max regardless of other factors. the load calculator may limit it even further for other reasons.
 
  #3  
Old 01-07-07, 06:10 PM
S
Member
Thread Starter
Join Date: Oct 2004
Location: USA
Posts: 33
Received 0 Votes on 0 Posts
I wanted to know what kind of load I am limited to cause i don't want to run a new wire.
thks
 
  #4  
Old 01-07-07, 08:49 PM
R
Member
Join Date: Sep 2003
Location: Central New York State
Posts: 13,973
Received 0 Votes on 0 Posts
If the water heater was wired as a typical water heater then you will need to run new wire. A water heater is a straight 240 volt load, and their is no neutral. A 240 volt sub panel needs a neutral.
 
  #5  
Old 01-08-07, 05:01 AM
S
Member
Thread Starter
Join Date: Oct 2004
Location: USA
Posts: 33
Received 0 Votes on 0 Posts
It's a 4 wire circuit. The old heater had 2 elements, one of which was hooked up to a separate meter - I think it only ran at night. So I have 4 wires to work with. Can the neutral be another color other than white if I mark it?
 
  #6  
Old 01-08-07, 05:04 AM
R
Member
Join Date: Sep 2003
Location: Central New York State
Posts: 13,973
Received 0 Votes on 0 Posts
No. The neutral must be white.
 
Reply
Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


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