Adcom A720, A723 Maintaining and servicing the RTU

CHAPTER 3

Maintaining and servicing the RTU

be fully charged after two consecutive sunny days, but you

should get an LED light-up after several minutes of charging

in the sunlight.

If you’re using an addIT RTU with an A730 system, you can conﬁg-

ure the RTU by following the steps described in the

addVANTAGE

A730 Releases Notes for Version 3.35

or in the

addVANTAGE 3.40

User Manual

. If you’re using the addIT RTU with addVANTAGE

Lite, follow the steps described in the addVANTAGE 4.1 Lite Refer-

ence Manual.

Maintaining and servicing the RTU

The A720 and A723 units need virtually no maintenance. They are

waterproof and designed to withstand harsh environmental condi-

tions (-30 to +70 °C, or -22 to 158 °F), high RH values, water, and

other noncorrosive liquids. They conform to the European protec-

tion class IP65. This applies also to the connectors, as long as they

are mated. Don’t let unmated connectors on either the addIT RTU

or the sensors be exposed to the environment for extended peri-

ods of time.

Note: The same type of battery is used in the A720/A723 and

A720B devices, so the information in this section also

applies to the A720B.

The internal battery supplies 6.2 volts and consists of a NiCd pack.

The internal electronics manage the battery charging/discharging

process, ensuring it a long life. This approach, coupled with a

remarkably low average consumption (some mere 6 mW), allows

an addIT RTU to operate at least one month on a fully charged

battery, with the following conditions:

• The channel has moderate radio activity, with requests every

15 minutes.

•Total consumption of attached sensors is no more than 50

mA.

• The sensors are sampled once every 5 minutes and an

averaged slot is stored in the internal memory every 15

minutes.