3000W Chinese Gensets Info.
professor95 wrote: EDIT ADDED 45/5/2013- When this thread started in March of 2005, I never expected to see it survive this long or amass the quantity of information that has been shared here. In...
Forum Discussion
ol Bombero-JC wrote:
A bit off topic for you Randy -
I've seen this one before - the topic caught my eye - and interesting speculation.
The question: Is there any harm (overheating) by leaving an RV power cord coiled either on the ground - or in a compt it's pulled out of?
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Clicky to thread
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Well, it is sort of like this:
The MAXIMUM length for a #10 AWG cord at 30 amps/120 VAC is 38 feet for no more than a 2% voltage drop. More than 38 feet of #10 cable "may" cause the cable to get warm or hot (depending on length and current). If I were operating in this mode I would prefer to have the cable outside in free air rather than a compartment. Actually, if heating occurs it will begin first at the plug, which is known to be the point of highest resistance.
BTW - #6 AWG operating at 50/50 amps can run up to 57' and be within the 2% or less voltage drop range.
Now, as for the inductance introduced by coiling.......
With AC flowing through an inductor the opposition to current flow is constantly changing at the frequency of the line voltage (60 Hz). Just how much inductance is introduced will depend on the number of turns and the diameter of the coil or circle. In the case of a coiled RV power cord at the maximum length and current noted above the added inductance is insignificant as far as cable heating.
If you want to play with numbers you can try this formula: I=R squared x N squared over / 9R+10L
N is the number of turns, R is the radius of the coil and L is the length of the stacked turns. I is the inductance in microhenrys (give or take 2%)
So, lets create a typical coil. The radius is 7" (7x7=49), There are 5 turns (5x5=25) 49 x 25 = 1225 (the numerator)
9x7 = 63; 10 x 12" = 120; 120 + 63 = 183 (denominator)
1225/183 = 6.70; or the inductance of the coiled cord is "about" seven microhenrys. This amount of inductance is trivial as far as cord heating is concerned. Current and length are the factors one needs to consider.
No, I'm not going to join the discussion on the thread you pointed to. If you want to share my comments it is your game - not mine. :B.
