voltage drop calculations

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BTE

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When using Holts free stuff for voltage calculations do I use 240 volts in the "select voltage" cell for a 240/120 volt single phase residential service voltage drop calculation?

BTE
 

charlie b

Moderator
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I am not familiar with that particular calculation tool. But in a manual calculation, you would use 240 volts. So I strongly suspect that Mike's calculation tool would use the same value.
 

kwired

Electron manager
Location
NE Nebraska
In general - yes 240.

When you do this you are assuming the neutral is fairly balanced and will not carry much current. If you know there will excess unbalanced load for some reason - you need to calculate drop of each conductor independently if you want more accurate results. This is not too hard to do - most formulas for calculating voltage drop for single phase circuits have a multiplier of 2 to include the return path. Just drop the "2" from the formula to get the "one way" calculation. If your neutral is different size than your ungrounded conductor you would need to calculate each segment separately anyhow for more accurate results.
 

iceworm

Curmudgeon still using printed IEEE Color Books
Location
North of the 65 parallel
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EE (Field - as little design as possible)
When using Holts free stuff for voltage calculations do I use 240 volts in the "select voltage" cell for a 240/120 volt single phase residential service voltage drop calculation? ...
The voltage drop is independent of the circuit voltage. Wire size, length, and current are the only things that matter.The only thing the calculator should use the voltage for is calculating the percent drop.

What is the circuit in question? Is it a 120V branch ckt to a device? Is it a 240V circuit. Pick the one that is right for your application.

Disclaimer:
I've never used a voltage drop calculator. I personally would never listen to anyone that has never used one - especially if they have not used the one in question.

ice
 

kwired

Electron manager
Location
NE Nebraska
The voltage drop is independent of the circuit voltage. Wire size, length, and current are the only things that matter.The only thing the calculator should use the voltage for is calculating the percent drop.

What is the circuit in question? Is it a 120V branch ckt to a device? Is it a 240V circuit. Pick the one that is right for your application.

Disclaimer:
I've never used a voltage drop calculator. I personally would never listen to anyone that has never used one - especially if they have not used the one in question.

ice

I think you may have just responded to someone that has never used the one in question.:happyyes:
 
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