Earth Ground - Toro DEC-RS-1000-DR Installation And User Manual

Earth Ground

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IMPORTANT! The Remote Gateway surge protection components cannot properly function unless an efficient
pathway to earth ground is provided. The ground path must be as direct as possible, without sharp bends and must
not exceed 30 Ohm resistance (when measured with an earth ground resistance device). All electrical components
throughout the irrigation system should be grounded similarly to provide the same ground potential.
The following instructions depict one of several acceptable earth grounding methods. Due to variables in soil composition
and terrain, the method shown may not be suitable for your installation site. Contact your local Toro distributor for
assistance and availability of the required earth ground resistance test instrument.
1. Drive a 5/8" x 8' (17mm x 2.5m) copper-clad steel rod into well moistened soil not less than 8' (2.5m) or not more
than 12' (3.7m) from the controller cabinet. The top of the ground rod should be flush with or below ground level and
protected from damage using a valve box. See Figure 2.
Installing a round valve box over the ground rod enables the ground rod to be easily located as well as providing
access to the ground wire connection(s).
2. Using a 5/8" (17mm) clamp or "Cad weld" fastener, attach an 8 AWG (8mm2) solid copper wire near the top of the
ground rod. Avoiding wire bends of less than 8" (20.3cm) radius and more than 90º, route the wire through conduit
and into the cabinet. Secure the wire to the copper ground lug.
Make sure the soil surrounding the ground rod(s) remains well moistened at all times. The addition of some form
of irrigation may be required if the cabinet is installed in a non-irrigated location.
3. Measure the ground resistance per the instructions provided with the ground test instrument. A reading of
0.0 Ohm is optimum, up to 10 Ohm is good and 11–30 Ohm is acceptable in most cases. If the resistance exceeds the
acceptable limit, additional ground rod(s) can be installed at a distance equal to twice the buried depth of the first rod;
i.e., 16' (4.9m) . Interconnect the ground rods using 8 AWG (8mm2) solid copper wire and test again. If the measured
ground resistance continues to read above the acceptable limit, contact your local Toro distributor for further assistance
and recommendations.
Figure 2
Valve Box
Ground Wire To
Additional Rod(s)
(Optional)
4
8 AWG (8mm2)
Solid Copper Ground Wire
8" (20.3cm)
Minimum Radius
8'–12'
(2.4m – 3.7m)
Copper Clad
Ground Rod
Ground Lug
90º Minimum Angle