winnie
Senior Member
- Location
- Springfield, MA, USA
- Occupation
- Electric motor research
Just to amplify: the how to calculate voltage drop in this circuit was clearly answered, with an example, in post 18 by drktmplr12. Others also answered the question, and emphasized that you can't really calculate voltage drop unless you _know the load_. A bigger load means more current and thus greater voltage drop.
The point is that with multiple loads and with multiple wire sizes, you need to do your calculation 'segment by segment' and then add up the voltage drops; a table (such as that shown) makes this much easier.
Your first segment is from the panel to the first receptacle. At this point the segment is carrying the entire load of the system, so you calculate your voltage drop from the length of the segment, the wire size, and the total load. This gives you your voltage drop and your voltage at the end of the segment.
Your next segment is from the first receptacle to the second. At this point your segment is carrying everything except the load from the first receptacle. You calculate your voltage drop for that segment, using as your 'starting voltage' the voltage at the beginning of the segment.
You keep going through all the segments.
-Jon
The point is that with multiple loads and with multiple wire sizes, you need to do your calculation 'segment by segment' and then add up the voltage drops; a table (such as that shown) makes this much easier.
Your first segment is from the panel to the first receptacle. At this point the segment is carrying the entire load of the system, so you calculate your voltage drop from the length of the segment, the wire size, and the total load. This gives you your voltage drop and your voltage at the end of the segment.
Your next segment is from the first receptacle to the second. At this point your segment is carrying everything except the load from the first receptacle. You calculate your voltage drop for that segment, using as your 'starting voltage' the voltage at the beginning of the segment.
You keep going through all the segments.
-Jon