Subpanel installation

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  #1  
Old 06-18-05, 01:07 PM
firewied
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Subpanel installation

I am an owner builder and am planning on wiring the house myself. It is a standard 3/2, 2000 sq feet. I have already had the service meter installed at a pump house on the property. I want to run underground from the pumphouse to the house. I plan on installing a 200 amp subpanel at the house. The service meter has a main service shutoff and a small panel to run the well. It has a through service connection. I need to know what size conduit and wire to run. It is a 200 foot run from the pumphouse to the house.
 
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  #2  
Old 06-18-05, 05:11 PM
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We need the pump electrical requirements.
 
  #3  
Old 06-18-05, 05:36 PM
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firewied,

I am not sure why we need the PUMP requirements because based on the post from what I can gather you are simply wanting to run the service for the HOUSE from the pumphouse which I am assuming already has maybe a 400A service in it.......here is why I ask....

If you have a 200A Service at the house running 200' from the pumphouse you have to account for voltage drop which in this case if you run 4/0 will give you about 3.3% Voltage drop or 8 volts from the 240V you started out with.

For the ease of PULL I would suggest you install 2 1/4" but code says you can install 2" and be fine. You will only need to pull (3) wires and I suggest you size the neutral equal ( 4/0 ) to the hot legs keeping it simple for yourself. ( Sure you may be able to get away with 2/0 for the neutral but on that distance I would stick to 4/0 personally. ) Also this is for P-40 PVC....P.S. You are going to need to drive a ground rod and many places today like in our area we have to drive (2) of them....but check with you local AHJ.

We see this alot in our RURAL area here in Virginia where we are in the poltry capital of the world...if not sure smells like it most of the time and the loop hole in the NEC for years caused many farmers to build the Farm House and Pump House first....then later build a house on the land and not have to get it inspected because of agricultural status and so on.....big issue here .

Personally I would like to see you hit a disconnect FIRST before piping out to the house since you have such a long route ( 200' )....

Every electrician is slightly different but this is what I gather you are trying to do.
 
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Old 06-18-05, 05:42 PM
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Sorry was jumping around and misread what you were wanting to do.
 
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Old 06-18-05, 06:14 PM
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No problemo Roger....Been their...Done that myself quite a few times....
 
  #6  
Old 06-18-05, 06:38 PM
firewied
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Thanks...I have a UFER ground in the foundation at the house. Which brings up another question, do I disconect the ground bar from the nuetral at the house panel or leave the tie in together.
 
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Old 06-18-05, 07:00 PM
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firewied,

Actually the system itself as whole will be bonded together in nature so you will end up having the ground rods tied with the UFER ground system which should be in the panel itself.

In some areas the UFER method may be all that is needed but it is strongly suggested you also suppliment with Ground Rods as well as normal your waterpipe at the place of enterance which is standard.

Here in VA if we have a UFER system we still drive the ground rod and bring BOTH to the panel and if needed we simply add a lug kit to the netural buss bar to handle it.

The point is the complete grounded system must be together at the panel.

here is a good article on UFER Grounds in case you are interested:

http://www.psihq.com/iread/ufergrnd.htm

I hope I answered your question clear enough..if not just yell back at me and I will go into more detail.
 
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Old 06-18-05, 07:05 PM
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firewied,

I may have gone into more detail that you needed...lol...Are you talking about the Grounding/Neutral Bar in the panel itself.....since you are running only 3 wires and is detached from the pumphouse you need to treat the panel at the house as if it came from the POLE itself...meaning you need to ground it as normal and in your case you have a UFER ground but I was saying I would personally suppliment it with a ground rod.

I also suggest you contact your local AHJ and ask them what they suggest as every local can have a variation they like...for example our area likes (2) ground rod....and no less...even if we can show 25 ohms or less to ground they would still demand (2) of them....

But as to your panel.....You need to make sure you have the GREEN screw in the panel showing the neutral/ground buss is bonded to the case. You need this because you are not doing a sub-panel here...and are not running a seperate ground wire because of the detached nature of the building.
 
  #9  
Old 06-18-05, 07:32 PM
firewied
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Would the UFER in combo with a single grounding rod be sufficient?
 
  #10  
Old 06-19-05, 04:55 AM
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firewied,

OK....this will be a AHJ call because take my house for example. I have a UFER system in mine and because of how it is done no ground rod was required by our local AHJ.....But in other counties I have done work in they require the mandated (2) Ground Rods as supplimental and a Water Pipe Ground ...UNLESS you do not have a waterpipe ground which can happen in the new homes with nothing but PEX or Plastic Plumbing pipe...so they like to always see multiples in grounding and bonding....sooooo

Depending on your waterpipe situation.....which chances are it is becoming a RARE breed anymore with all the plastic we are using....you will still need a grounding and supplimental....so I would do both....UFER and a ground rod in my opinion....Now how many Ground Rods...well I would call the local AHJ just to be sure as like with many counties I deal in..they dont care what I say of if I pull out the " Earth Ground Testing Kit " which I do have BTW...lol....some call it ANAL..I call it " Fun Testing "...I have shown inspectors less than 25 ohms to ground and they still insist on (2) rods so it really would be wise to just call them and ask to speak to the head inspector and ask them what the minimum they are going to require is going to be.

Saves alot of head ache in the end because every inspector may look at something totally different...and even though I know the NEC it never seems to stop amazing me what they want next.

But on a personal note...if it were me....(1) UFER and (1) GR would be all I would do unless they asked for more....can always drive another GR if needed....lol ( Note: If you do make sure it is a minimum 6' from the first GR...
 
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