Length of 110V circuit

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69boss302

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Though there is no where that specifically limits the distance you can run a circuit, it's all just a matter of proper wire sizing and derating, I am trying to explain good reasoning to not run 110V ckt 500ft down a warehouse. There is no 110V service on the one end of our warehouse, they have already installed a few things fans, turn and lift tables, stretch wrapper and not want to add more equipment. My only real argument is that it's just not good engineering practice to run all of these 110V circuits 500ft down the building. We should really get a 480/120 transformer and provide a service and panel to the other end of the building. Conduit runs are large and obtrusive and the whole set up just looks unprofessional. I'm just wondering if any one has any real kind of documentation I could use to show in black and white that all these runs are just not the best practice.
 
69boss302 said:
Though there is no where that specifically limits the distance you can run a circuit, it's all just a matter of proper wire sizing and derating, I am trying to explain good reasoning to not run 110V ckt 500ft down a warehouse. There is no 110V service on the one end of our warehouse, they have already installed a few things fans, turn and lift tables, stretch wrapper and not want to add more equipment. My only real argument is that it's just not good engineering practice to run all of these 110V circuits 500ft down the building. We should really get a 480/120 transformer and provide a service and panel to the other end of the building. Conduit runs are large and obtrusive and the whole set up just looks unprofessional. I'm just wondering if any one has any real kind of documentation I could use to show in black and white that all these runs are just not the best practice.
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Calculate the load that will be fed, with some allowances for more later. Then decide on an acceptable voltage drop (3% is a good guideline, but if you need to allow for motor starts and any of the other equipment will react badly to voltage dips (like lights, with annoyance factor) you want to do better than that.

Now price out the cost of 500' of wiring of the required size to better that voltage drop and the conduit needed to hold it, including the ECG if the raceway will not qualify.
If that is not persuasive, just run the long wires.

It is always hard to accept the assurance that they will not want to add more equipment. But they are the customer....
 
Thanks GoldDigger, that's what I'm dealing with we just keep running the long wires. I'm in the situation where I could be sitting at the table with two project engineers doing two different projects and one of them wont even let you bump up the conduit size so we can run two ckt's in one conduit. I've literally had a situation where of course two ckt's will fit into a 1/2" but noooooooo don't you dare put part of the other engineers cost in my cost. Two jobs two independent quotes, two independent ckt's. WE WILL NOT WORK TOGETHER!!!!!!!!! AND FOR PITY SAKE DON'T YOU TRY TO COMMUNICATE!
 
Long Run Transformation

Long Run Transformation

I occasionally do the transformation. On airports it is not uncommon to go from 240V single phase to 600V, run 3000 feet, then transform back to 120/240V for several kW of load. Not good for motor starting but OK for steady loads.
 
69boss302 said:
Though there is no where that specifically limits the distance you can run a circuit, it's all just a matter of proper wire sizing and derating, I am trying to explain good reasoning to not run 110V ckt 500ft down a warehouse. There is no 110V service on the one end of our warehouse, they have already installed a few things fans, turn and lift tables, stretch wrapper and not want to add more equipment. My only real argument is that it's just not good engineering practice to run all of these 110V circuits 500ft down the building. We should really get a 480/120 transformer and provide a service and panel to the other end of the building. Conduit runs are large and obtrusive and the whole set up just looks unprofessional. I'm just wondering if any one has any real kind of documentation I could use to show in black and white that all these runs are just not the best practice.
Click to expand...

The things you listed as a 'cons' are just how it looks to you. There is nothing wrong with a 500' long 120 volt circuit.

In my opinion the only issue becomes cost, will it cost more to run larger conductors or cost more to use a transformer?
 
69boss302 said:
Thanks GoldDigger, that's what I'm dealing with we just keep running the long wires. I'm in the situation where I could be sitting at the table with two project engineers doing two different projects and one of them wont even let you bump up the conduit size so we can run two ckt's in one conduit. I've literally had a situation where of course two ckt's will fit into a 1/2" but noooooooo don't you dare put part of the other engineers cost in my cost. Two jobs two independent quotes, two independent ckt's. WE WILL NOT WORK TOGETHER!!!!!!!!! AND FOR PITY SAKE DON'T YOU TRY TO COMMUNICATE!
Click to expand...

Ya ain't doing it right.

I worked at a college for 10 years and ran into this all the time.

What I did is price out each run and bill accordingly, then bump up the run size, run a full boat ( 4W MWBC), and be ready for the next dept. that needs a circuit.

My dept. got to keep the extra money and the boss was very happy.
 
69boss302 said:
Though there is no where that specifically limits the distance you can run a circuit, it's all just a matter of proper wire sizing and derating, I am trying to explain good reasoning to not run 110V ckt 500ft down a warehouse. There is no 110V service on the one end of our warehouse, they have already installed a few things fans, turn and lift tables, stretch wrapper and not want to add more equipment. My only real argument is that it's just not good engineering practice to run all of these 110V circuits 500ft down the building. We should really get a 480/120 transformer and provide a service and panel to the other end of the building. Conduit runs are large and obtrusive and the whole set up just looks unprofessional. I'm just wondering if any one has any real kind of documentation I could use to show in black and white that all these runs are just not the best practice.
Click to expand...

What you are calling "service" is what NEC calls "separately derived system".

I agree with others, cost is the bottom line, either method is code compliant.
 
GoldDigger said:
Calculate the load that will be fed, with some allowances for more later. Then decide on an acceptable voltage drop (3% is a good guideline, but if you need to allow for motor starts and any of the other equipment will react badly to voltage dips (like lights, with annoyance factor) you want to do better than that.

Now price out the cost of 500' of wiring of the required size to better that voltage drop and the conduit needed to hold it, including the ECG if the raceway will not qualify.
If that is not persuasive, just run the long wires.

...
Click to expand...
Should include cost of I?R losses in the comparison.
 
Thanks Everybody, I guess I should of also added that I am on the company side, I am trying to work with company project engineers and trying to explain to them that it is silly to run all these seperat circuits. The contractors love it, they'll run as many seperat circuits as the engineers ask, and pull in all the money they can. As I said, I realize all it takes is bumping up wire sizes and running conduit the distance, just wanted to make it a little simpler for maintenance sake and tracing out circuits. for isolation.
 
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