Rain Bird ESP-SMT User Manual

ESP-SMT Smart Modular Control System
79
Applying the “Cycle and Soak” Principle
In most soil types, you would not want to run the zone’s
irrigation system for one hour in duration as this would
most likely cause signicant water loss through runo.
Based on the soil type and degree of slope information
entered into the controller for the zone, the ESP-SMT
controller will determine the maximum “cycle” time and
minimum “soak” time required to irrigate without runo.
These prescribed cycle and soak times are based on
the Water Intake rate of the soil type as identied in the
following tables:
Soil Type or Class Basic Intake Rate
Soil Type or Class
Basic Intake Rate
(inches per hour)
Sand 0.60”
Loamy Sand 0.50”
Sandy Loam 0.40”
Loam 0.35”
Clay Loam 0.20”
Silty Clay 0.15”
Clay 0.10”
This process would continue on a daily basis as shown is
the table below:
Illustrative Scheduling Example
Day ET/Day
Effective
Rain
Net Water
Req’t
Accumula-
ted Water
Req’t
Irrigation
Event
1 0.18” 0.00” 0.18” 0.18” ---
2 0.16” 0.00” 0.16” 0.34” ---
3 0.16” 0.16” 0.00” 0.34” ---
4 0.18” 0.00” 0.18” 0.52” 0.53”
5 0.14” 0.00” 0.14” 0.13” ---
6 0.13” 0.10” 0.03” 0.16” ---
7 0.15” 0.11” 0.04” 0.20” ---
8 0.14” 0.00” 0.14” 0.34” ---
9 0.11” 0.00” 0.11” 0.45” ---
10 0.16” 0.00” 0.16” 0.61” 0.60”
11 0.12” 0.00” 0.12” 0.13” ---
12 0.12” 0.00” 0.12” 0.25” ---
In this example the irrigation schedule for the zone would be:
Day 4 - 60 minutes (Cycle 1 = 30 minutes & Cycle 2 = 30 minutes)
Day 10 – 68 minutes (Cycle 1 = 30 minutes, Cycle 2 = 30 minutes,
Cycle 3 = 8 minutes).

Rain Bird ESP-SMT Specifications

General

Brand	Rain Bird
Model	ESP-SMT
Category	Controller
Language	English