Hit Products Logic 3 - Manual (Page 4)

VALVE WIRING
The field wiring from the controller to the receivers consists of either one or two, 2-wire
runs, which connect, in series, to each valve location. Each 2-wire run is totally
independent of the other relative to wire size requirements and the number of valves
operating simultaneously. Both 2-wire runs receive and output the exact same
information. The purpose of 2 independent 2 wire runs are for reducing the potential
amount of “back tracking” when valves are located in more than one general direction
from the controller. Theoretically, with the Logic controller located in the center of an
irrigation project, one 2-wire run would go one direction and the other 2-wire run could
go the other direction. “Line 1” is one 2-wire run; “Line 2” is the second available 2-wire
run. The 2-wire runs start at the controller and end at the last receiver/valve for that wire
run. Do not loop or make a complete connected circle.
For the main 2-wire runs, it is very important to size the wire properly.
Consideration for designing the proper wire size includes the total wire distance
from controller to the farthest receiver and how many valves will be operating
simultaneously. Wire size must be designed using Ohm’s law for any
application.
The field wiring should consist of one or two continuous main 2 wire runs starting at the
controller terminal labeled “Line 1” or “Line 2” continuing to the last receiver/valve of
that wire run. If using the dual output feature, use one continuous length of wire
independently from each output “Line 1” and the second independent 2 wire run from
“Line 2”. Every receiver is to be connected directly anywhere on one of your main two-
wire continuous runs. Do not tee or branch the main two wire runs. To access remote
valve(s), attach the two red receiver wires (one red wire to each field wire) of the main
two wire run. Extend the black solenoid leads from the receiver and attach to the solenoid
at the valve. The distance from a receiver to the solenoid is limited only by standard wire
sizing/distance and voltage drop parameters. From the controller to the solenoid the
voltage can not exceed 7 voltage loss. The last receiver installed is the end of the main
two wire run. You may operate a maximum of four of the same numbered receivers or
four valves maximum of any random numbered receivers at any one time. This will
affect the wire size, as more power draw will be needed. (See wire-sizing guide.)
Use the following formula when designing your wire size for each Logic 2 wire run.
Consult attached wire charts to insure proper wire gage. Minimum wire size and type is
14 Ga. Always use direct bury, heavy jacket, solid core copper wire
.
Wire Size Formula is: VD = C x R x (2L) / 1000
"Ohms Law" Voltage Drop = Current x Resistance in Ohms
VD = Voltage Drop
C = Current (Solenoid Amperage Draw)
R = Resistance (Wire Size “Voltage Loss” Factor)
L = Length of distance between controller and valve in feet
2
Wire
Size
Ohms Per
1,000 Ft.
14 2.580
12 1.620
10 1.020
8 0.641
6 0.403
4 0.253