Need some guidance on subpanel wiring.

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  #1  
Old 01-08-15, 12:28 AM
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Need some guidance on subpanel wiring.

My house is currently run on 14-2 without ground on a single 50 amp breaker. (That is all lights and receptacles. A new fridge, stove, water heater, and ac each have there own dedicated circuits.) The main breaker panel is full so I plan to install a panel indoors.

First, I wanted to check that it is acceptable to run wire from the main panel like this:



This is where I plan to put the indoor panel. I think it's a 3 phase panel, but I'm pretty sure it can be modified to work for me.



Finally, the guy who installed the new 4 new appliances and ran power to them ran conduit directly to the outlet.



I plan to rework these so it's neater, but I wanted to check if I have to bury all the conduit going from the pole to the house or if it is acceptable to hang the conduit from the floor joists. It seems like it would be a real pain to dig a 20" trench in my crawlspace.

Any help is appreciated!
 
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Old 01-08-15, 03:15 AM
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Welcome to the forums! Clarify this for us, please
My house is currently run on 14-2 without ground on a single 50 amp breaker
What size main breaker do you have? Where does the 14-2 come in? It must be your branch circuit wiring,as it is too small for your primary feed.
 
  #3  
Old 01-08-15, 03:35 AM
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The conduit does not need to be buried in the crawlspace.
 
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Old 01-08-15, 04:54 AM
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It looks tight - you need 36" free space in front of any panel.

Don't use a 3 phase panel - it causes too many long term problems.
 
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Old 01-08-15, 05:20 AM
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You can use the feed-through lugs as you propose only if the maximum amp rating of the subpanel is greater than or equal to that of the main panel. The subpanel does not need a main breaker if it is in the same building as the main.
 
  #6  
Old 01-08-15, 08:29 AM
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It may in fact be 12-2, but it all goes to the single 50amp breaker on the top right of the panel, with the two pale blue wires connected. This and the absence of a ground wire throughout the house is what prompted me to open up the walls in the first place.
 
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Old 01-08-15, 08:39 AM
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I'm aware. The interior image with the empty panel photoshopped for placement will have the required clearance. That is a temporary support intruding on the 36" clearance because the load bearing wall in which I will be installing the panel has been decimated by termites.
 
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Old 01-08-15, 08:42 AM
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It may in fact be 12-2, but it all goes to the single 50amp breaker on the top right of the panel, with the two pale blue wires connected.
12-2 indicates a cable with conductors that must be protected at 20 amps. 14-2 indicates a cable with conductors that must be protected at 15 amps. Both have one black and one white conductor and usually also include a equipment grounding conductor. It appears you have individual wires in conduit and not a cable. What makes you think the two small wires feed the entire house?
 
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Old 01-08-15, 08:44 AM
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"Feed-through lugs," very good. I wasn't sure that was actually what those were for. The 3 phase indoor panel is rated 200amps, same as the main , posted just outside.
 
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Old 01-08-15, 09:04 AM
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Am I missing something here?
Are you saying you have a multi-wire circuit, 50amps, feeding all lights and receptacles???
 
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Old 01-08-15, 09:14 AM
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Actually, the OP in post #1 stated.....

My house is currently run on 14-2 without ground on a single 50 amp breaker
That is why I questioned.....

What makes you think the two small wires feed the entire house?
 
  #12  
Old 01-08-15, 09:15 AM
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I measured the wire at a receptacle with a micrometer before opening the walls and it converted to around 13 gauge. This building is an addition to existing property and was originally run by a single 50amp breaker at the other house. This breaker has since been moved to a newly installed utility pole so my grandmother would have a separate utilities. There is old and new cable installed. The previous owners installed 3 prong receptacles by splicing into the old 2 prong receptacles with 12-2 w/g and leaving the ground hanging at the old box.



Actually I just looked at it and the old sheathed cable does say 12-2. I am aware that the circuits are not supposed to have smaller rated wire than the ocpd they are downline from. Again, that and the lack of ground is the reason I am rewiring the house.
 
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Old 01-08-15, 09:19 AM
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Yes, that is correct. Extremely dangerous, I know. Me and my brother lived here for a year, then my grandmother for 3 years, and now I'll be staying here as I finish college.
 
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Old 01-08-15, 09:25 AM
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You would also made aware of other issues with the panel at the other forum. Combine the comments from both and formulate a solid plan.

The blue box shown in the one picture is an old work box.
 
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Old 01-08-15, 09:37 AM
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Indeed. Your responses have been most helpful. All the boxes will be removed and replaced with new work. I have also already installed can lights. All that remains is installing a shower, removing and rewiring the house, and closing it back up. And thanks for the comment about the crawlspace.
 
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Old 01-08-15, 09:47 AM
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Yes Joe, Thanks. I know you're on top of this.
Sogeki, Please use this forum to get this right, you have a lot going on there.
 
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Old 01-08-15, 10:54 AM
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Looks like you've got quite a job ahead of you. In my post I should have also made it clear that the wiring between the panels (from the feed through lugs to the subpanel) also has to be rated for 200A. It essentially functions as an extension of the main panel. Do you know which NEC revision your area follows? In the conduit, your hots and neutral would need to be at least #4/0 al or #2/0 copper with a #4al or #6cu ground. A larger size might be required if you have to follow one of the more recent NEC versions.
 
  #18  
Old 01-08-15, 06:58 PM
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Assuming the subpanel feeder is exiting the panel through the bottom conduit, it appears to me that the conduit is just butted up to the bottom of the panel and doesn't have a terminating connector that enters the panel and should be secured with a locknut. That leaves the wires exposed to the sharp edges of the knockout. If this is corerect, this needs to go on your list in the not-too-distant future.
 
  #19  
Old 01-08-15, 07:18 PM
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That image is photoshopped to show the panel and it's placement. I haven't bought the 2" PVC yet. Current:

 
  #20  
Old 01-08-15, 07:21 PM
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In my post I should have also made it clear that the wiring between the panels (from the feed through lugs to the subpanel) also has to be rated for 200A.
Yes, in my original post is an image with the sizes and routing I plan to use.
 
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