Hello All,
I was reading an article on series voltage drop in EC&M and part of the example has me baffled and hope some of you can make sense of it for me.
The example is a string of five luminaires equally spaced at 200 feet. Voltage is 240volt using #10 AWG copper in PVC with each luminaire having a load of 1.354 amperes. The length of conductors from the panel to the first luminaire is also 200 feet.
The writer states the following: "the % Vd equals 100 x (Vd x 240). The % Vd for each segment is equal to (0.650V ? 240V) x 100=0.271%.
The respective currents for the five segments are 6.77amperes, 5.416amperes, 4.062amperes, 2.708amperes, and 1.354amperes.
The respective cumulative % Vd for the five segments are 1.354%, 2.437%, 3.250%, 3.792%, and 4.063% for the final luminaire position.
If using #10 AWG conductors for the entire 1,000' to the last luminaire, wouldn't the Vd decrease from the first luminaire at (1.354% Vd) to the last luminaire? How would the writer come up with 4.063% Vd for the last 200' of the string using #10 AWG?
Thank you all in advance for your help and comments.
Errol
I was reading an article on series voltage drop in EC&M and part of the example has me baffled and hope some of you can make sense of it for me.
The example is a string of five luminaires equally spaced at 200 feet. Voltage is 240volt using #10 AWG copper in PVC with each luminaire having a load of 1.354 amperes. The length of conductors from the panel to the first luminaire is also 200 feet.
The writer states the following: "the % Vd equals 100 x (Vd x 240). The % Vd for each segment is equal to (0.650V ? 240V) x 100=0.271%.
The respective currents for the five segments are 6.77amperes, 5.416amperes, 4.062amperes, 2.708amperes, and 1.354amperes.
The respective cumulative % Vd for the five segments are 1.354%, 2.437%, 3.250%, 3.792%, and 4.063% for the final luminaire position.
If using #10 AWG conductors for the entire 1,000' to the last luminaire, wouldn't the Vd decrease from the first luminaire at (1.354% Vd) to the last luminaire? How would the writer come up with 4.063% Vd for the last 200' of the string using #10 AWG?
Thank you all in advance for your help and comments.
Errol