Voltage Drop

[jap]

My weakness,


When you calculate for voltage drop, do you calculate for the amperage of the breaker or for the calculated load?

Say your feeding a workshop 200' away from the service 120/240v single phase and the customer is going to be running small woodworking equipment in it. (not all running at the same time).
If you were to install a 2p 100a breaker at the service do you calculate the voltage drop for 100 amp? or the calculated load.

Also do you use 240v when calculating the drop since its 120/240 or 120 since most all the loads are 120v.

 

[Ranger86]

I would be on the conservative side since they may be adding more loads in the future.
I would do the VD calc for at least 80A @ 240V.

 

[Dennis Alwon]

To answer the question one does VD based on the load however, as stated above, if there will be expansion you may want to size it larger. You use 240V for the calculation.