User's Manual

CHAPTER2
MaintainingandservicingtheRTU
11
To configure the addSWITCH RTU in your A840 or A850 Telemetry
Gateway and addVANTAGE Pro, please check the respective user
guide.
MaintainingandservicingtheRTU
A Series 4 RTU needs virtually no maintenance. It is waterproof and
designed to withstand harsh environmental conditions (-30 to +70 °C,
or -22 to 158 °F), high RH values, water, and other non-corrosive
liquids. It conforms to the European protection class IP65. This applies
also to the connectors, as long as they are mated. Don’t let unmated
connectors on either the RTU or the sensors be exposed to the
environment for extended periods of time as this might seriously
affect their functionality.
TheRTUbattery
The internal battery supplies 6.2 volts and consists of a NiMH pack.
The internal electronics manage the battery’s charging/discharging
process, ensuring it a long life time. This approach, coupled with a
remarkably low average power consumption, allows an RTU to operate
at least two weeks on a fully charged battery, under the following
conditions:
• The radio channel used has moderate radio activity, with requests
every 15 minutes.
• The analog and the counter values are stored in the internal
memory every 15 minutes.
• No more than 40 valve activations per day (12V Type).
Table 1 shows the addSWITCH device’s expected operation time on a
fully charged battery under various conditions.
Note: “Radio activity” means that one base station and one to three RTUs
are active on the same operating frequency and within the
transmission distance of the addSWITCH.
However, if for some reason (wearout or accident) the battery loses
its capacity (noted in the software with repeated “Battery low”
Table 1. addSWITCH Device Operation Time
Radio
Activity
Valve Actions
Average
Consumption
(mA)
Estimated
Operation
(days)
No none 0.667 100
Yes none 0.833 80
Yes 40 1.8 37