6
Before you decommission your existing RTU, exercise each sensor to confirm
they are working properly. This will allow your final tests of the MyDro to be
conclusive.
To minimize down time, confirm that the MyDro RTU is ready for installation.
Temporarily connect an antenna and power up the uninstalled MyDro RTU with
battery power to ensure the radio is active and the carrier is appropriate for your
location.
Chapter 2: Before Disassembly
Familiarize yourself with what you have by looking at the I/O descriptions and
configuration of your web portal. Confirm those details by evaluating existing
local wiring and then correct or update your local labeling. Review the MyDro
150/850 Installation Manual prior to upgrading an existing RTU.
Use the camera in your smartphone to capture the wiring of your existing RTU.
Individually label non-obvious conductors.
Power In
The top two terminals on the left are generally where power from the 120 volts to
12 VAC transformer enters (in some cases solar power). The new wiring will be
the same unless this is a solar-powered RTU. Power supplied by a solar panel is
polarity sensitive. An independent solar charge regulator is recommended.
Battery Power
The battery terminals are controlled by a smart charging circuit that reduces
current as the battery voltage approaches 13 volts. Even with solar panels, where
20 VDC is not uncommon, the voltage will be regulated to not overcharge the
battery.
Auxiliary Power
The voltage provided by the auxiliary (aux) power terminals is software selectable
as 0, 12, or 24 VDC. The aux terminals of the Legacy RTU supplied 12–16 VDC.
The 24 VDC option is the preferred voltage for most 4–20 mA transducers. Any
components powered by aux must complement your aux voltage setting.
