voltage drop 425 feet help

[iwire]

Agree. Likely 10% wouldn't matter.

That really depends.

Sure the equipment will work but will the customer be happy?


Consider this, the customer has 5 amps of lighting on, works fine. Now the 26 amp hot water heater kicks on and the lights noticably dim. Water heater goes off, lights brighten.

Now this might not be a problem at all, or it could drive the customer nuts and then what?

Or the customer had an air compressor that kicks out the OLs instead of starting due to voltage drop at LRC.

My point here is I wire for no call backs.

 

[kwired]

That really depends.

Sure the equipment will work but will the customer be happy?


Consider this, the customer has 5 amps of lighting on, works fine. Now the 26 amp hot water heater kicks on and the lights noticably dim. Water heater goes off, lights brighten.

Now this might not be a problem at all, or it could drive the customer nuts and then what?

Or the customer had an air compressor that kicks out the OLs instead of starting due to voltage drop at LRC.

My point here is I wire for no call backs.

And from knowing the places you frequently work in that is understandable, how much farm wiring have you done? You do have to be particular with some of it, but the average "old barn" doesn't require being too particular in most cases. Of course OP did not really tell us exactly what his application was either - just called it a barn and said he had existing 1-1/2 conduit to deal with.

 

[iwire]

And from knowing the places you frequently work in that is understandable, how much farm wiring have you done? You do have to be particular with some of it, but the average "old barn" doesn't require being too particular in most cases. Of course OP did not really tell us exactly what his application was either - just called it a barn and said he had existing 1-1/2 conduit to deal with.

Electricity works the same in farms as it does in supermarkets. If you are saying farmers are less picky so ECs can cheat more I can't argue with that.


If you had read his other thread you would know the loads are lighting and water heaters. I do not know what kind of heaters, might just be the ones to keep the water from freezing I do not know.

The original plan was a 100 amp panel with a 100 amp feeder.

 

[kwired]

Electricity works the same in farms as it does in supermarkets.

Fully understand that.

If you are saying farmers are less picky so ECs can cheat more I can't argue with that.

Not saying they all are, and many will have a different approach at the barn than the house, but this is for the "old fashioned barn". Todays barns that are used to raise livestock for profit are not hardly the same thing at all, and some are essentially a "small industrial plant" I have a dairy farmer I do work for - the "barn" is fed with 800 amp 480 volt service, has a lot of machines and electronics inside.

Had no idea about any other thread.

 

[ActionDave]

My point here is I wire for no call backs.

I wire based on what the customer wants and is willing to pay for.

And my point was voltage drop seems to be something a lot of people worry about too much. I know there are times when it has to be considered, but not as often as some would think.

 

[Deanos]

spoke with inspector.

spoke with inspector.

He, and myself bolth decided 1/0 with # 10 ground on a 60 overcurrent would work. The barn will draw around 48amps. At the barn I will drive two ground rods. There is a well pipe from the home to the barn. At the panel in the barn the grounds and N will be seperated, thought about derating the neutral but the run is pretty far. So the info needed thus far is, 120/240v 200a at the home, 425 feet run to the barn, 1 & 1/2 pvc existing pvc, current draw "approx" 48 amps, 60 amp main to feed the barn. Open to any other suggestions, thanks. And I did apologize to the mod on the last site, it was a bad day!:dunce:

 

[augie47]

Locally that would not pass inspection due to the #10 ground {250.122(B)}

(Previously pointed out in Post #30)

 

[ptonsparky]

Voltage drop with an undersized EG is a problem. It is part of the circuit during fault conditions when you need enough current flow to trip the feeder OC protection. #10 is to small for this circuit.

 

[edlee]

Two rods, isolated from the neutral, meets current code. #10 ground is too small though.........like Augie says. You're supposed to upsize for the VD just like the other cables.

 

[ptonsparky]

Do a VD drop calculation for #10 wire using 120v and 60 amp load at 425'. Subtract that VD from your applied voltage. That is the voltage that will be on the side of every piece of bonded metal at your barn, until the breaker trips. How long does it take a 60 amp CB to trip with a 60 amp load?

 

[kwired]

When there is an increase in ungrounded conductor size the equipment grounding conductor needs increased by the same proportion, some of the last few posts help explain why.

 

[Smart $]

... Open to any other suggestions...

Do a service conductor tap, load side of meter, line side of service disconnect, or in between. Run L1 & L2 unfused and Neutral to barn. No EGC required. Put 60A service-rated panel at barn. Install rods. GEC(s) to rods and water line if metallic in 10' of earth. Connect GEC(s) to neutral, and bond neutral to equipment ground with manufacturer-provided MBJ.

 

[Deanos]

I think there are more than one way to skin a cat for sure, Im more confused than when I started. Mr ED is gonna freeze:happyyes:

 

[ptonsparky]

I think there are more than one way to skin a cat for sure, Im more confused than when I started. Mr ED is gonna freeze:happyyes:

Poor Ed.

The advantage of being an EC is you get impress your customer with all the various ways to accomplish the task, or offer two or three with pros & cons of each.

 

[iwire]

I wire based on what the customer wants and is willing to pay for..

Getting paid is almost worthless if the customer is not happy with the results.

And my point was voltage drop seems to be something a lot of people worry about too much. I know there are times when it has to be considered, but not as often as some would think

I agree to a point, but that point for me is crossed well before 425' at 240 volts with 50 amps of load. Voltage drop will be a factor here.

We do many long circuits, we have run 4AWG copper for 20 amp HVAC service outlets due to distances.

 

[Dennis Alwon]

Deanos, if you increase the conductors for VD then the equipment grounding conductor must be increased proportionally, as others have stated. This is an issue when the distance is very large, as in the case you stated. The impedance of the #10 wire over that distance is greatly increase and can cause the OVERCURRENT PROTECTIVE DEVICE to not function when a ground fault occurs. Inspector may okay the install but that would because of ignorance of the article stated or lack of understanding as to why this is important. Granted if you had a 10' run with the same conductors this would not be an issue but 425' may very well an issue.

 

[Dennis Alwon]

BTW, here is a post from George on how to calculate the upsizing of the equipment grounding conductor if you are unfamiliar with it.

http://forums.mikeholt.com/showthread.php?t=83435&page=2&p=649545#post649545