Reference
Reference
117 Volt Primary Wire Sizing Procedure
- Determine current requirements of controller unit, master valve, and
station valves from electrical current requirement chart.
- Determine maximum allowable voltage drop.
a. Determine voltage at power source
b. Determine voltage desired at controller (limits: 105V minimum
and 128V maximum)
- Calculate equivalent circuit length.
- Using formula, calculate “F” factor:
Allowable Voltage Drop
F =
Amps (per unit) x Equiv. Length (in 1000s of feet)
- Select power wire size from wire size chart (select wire size
with an “F” factor equal to or less than the calculated “F” factor).
Controllers and Valves
Type of Controller 117 Volt Primary Current
or Valve Requirements (Amps)
Controllers With Power On
Only Not in a Cycle
RC-Bi 0.13
RC-C 0.13
ESP 0.03
ESP-Si 0.06
E-Class 0.06
Ec 0.07
ESP-LXi+ 0.15
ESP-LX+ 0.15
ESP-MC 0.18
IM 0.20
Valves Current Draw
Only When Energized
Solenoid Valve 0.07
Wire Size
Wire Size “F” Factor
#18 13.02
#16 8.18
#14 5.16
#12 3.24
#10 2.04
#8 1.28
#6 0.81
#4 0.51
Electrical Current Requirements
Example
- Controller Primary Current Requirements
(from electrical current requirement chart):
RC-7C controller only .13
2 solenoid valves (2 x .07) .14
Total .27 Amps
- Maximum allowable voltage drop:
a. Power source = 119V
b. Desired voltage at controller (min) = 112V
Volts drop allowable = 119V - 112V = 7V
- Equivalent circuit length:
1 (Controller A) x 1000' = 1000'
2 (Controller A & B) x 2000' = 4000'
Total = 5000' = 5.0 (in 1000s of feet)
4.
7V
F =
.27 Amps x 5
= 5.19
- Wire size required: From wire size chart select size #14 wire
(chart value = 5.16)
Power
Source
2000' (actual length)
RC-7C with 2
Valves Per Station
1000' (actual length)
