Your knowledge and experience serves you well when working in the field. But working in the field is one thing, applying the appropriate codes and calculations when answering exam questions is another. Can you answer the following voltage drop question with ease?
Question:
What is the voltage dropped across #8 gauge solid uncoated conductors that supply a 30 amp load if the distance between source and load is 180 feet and the source voltage is 120 volt single-phase?
To answer this question correctly you need to know the following:
What is the difference between coated verses uncoated conductors?
What is the difference in resistance between solid verse stranded wire?
Should copper or aluminum wire resistance values be used?
Where can the resistance for #8 gauge solid uncoated conductor be found in the code?
What is the difference between actual verses code permitted voltage drop in conductors?
Having the background knowledge required to answer these questions is the key to answering voltage drop exam questions correctly.
Solution:
VD = Voltage Drop
I = Amps
R = Resistance
VD = I x R (R=resistance per full length of conductor used)
=30 amps x 0.27504 ohms {.764 ohms x .360)
=8.25 volts dropped
Preparation is the key to being able to answer these kinds of questions quickly and easily. We’ll help you to understand exam question terminology and develop the test taking skills you’ll need to succeed. Call 888-919-3926 to start preparing to pass your exam today.