Irrigation & Lighting Division

Maximum Wire Runs for Solenoid Valve Circuits (Feet)

(Conventional Irrigation Systems, one way distance)

For controller output of 24 volts (4-volt allowable drop):
AMERICAN WIRE GAUGE (AWG)
Number of Solenoids per Circuit 18 16 14 14/12 14/10 12 10 8 6
1     782  1,243  1,980  2,432  2,841  3,151  5,025    7,962  12,376
2     391     622     990  1,216  1,420  1,575  2,513    3,981    6,188
3     261     414     660     811     947  1,050  1,675    2,654    4,125
4     196     311     495     608     710     788  1,256    1,990    3,094
5     156     249     396     486     568     630  1,005    1,592    2,475
6     130     207     330     405     473     525     838    1,327    2,063
7     112     178     283     347     406     450     718    1,137    1,768
8  -      155     248     304     355     394     628       995    1,547
9  -      138     220     270     316     350     558       885    1,375
10  -      124     198     243     284     315     503       796    1,238

For controller output of 26.5 volts (6.5-volt allowable drop):

AMERICAN WIRE GAUGE (AWG)
Number of Solenoids per Circuit 18 16 14 14/12 14/10 12 10 8 6
1  1,272  2,021  3,218  3,952  4,616  5,120  8,166  12,938  20,111
2     636  1,010  1,609  1,976  2,308  2,560  4,083    6,469  10,056
3     424     674  1,073  1,317  1,539  1,707  2,722    4,313    6,704
4     318     505     804     988  1,154  1,280  2,041    3,234    5,028
5     254     404     644     790     923  1,024  1,633    2,588    4,022
6     212     337     536     659     769     853  1,361    2,156    3,352
7     182     289     460     565     659     731  1,167    1,848    2,873
8  -      253     402     494     577     640  1,021    1,617    2,514
9  -      225     358     439     513     569     907    1,438    2,235
10  -      202     322     395     462     512     817    1,294    2,011
 
note:
  1. For multiple solenoids in a circuit, they are assumed to be located within a few feet of each other.
  2. Assumes that the "hot/control" wire and "common" wire are the same size.  If the AWG is shown as 14/12, it means that the "hot/control" wire is 14 AWG and the "common" wire is 12 AWG.
  3. The minimum operating voltage of the solenoid is 20 volts.
  4. The inrush current of the solenoid is 0.400 amperes.
  5. A 20% safety factor is built into the calculation to allow for brownouts, splice deterioration, solenoid aging, etc.