Casella CEL Automatic weather station - Manual (Page 14)

2.7 System Power Supply
The weather station system can derive its power supply from a variety of
alternative energy sources such as via a land line interface, solar panel array,
wind power, or a local mains supply.
2.7.1 Solar Power Installations
The solar panel support structure should be assembled according to the solar
panel drawing in the “Calibration & System Details” section of this manual.
The Sensus Logger incorporates a solar power regulator as standard.
This can operate with nominal 12 V solar panels with outputs up to 40 W with a
short circuit current of no more than 2.5 A.
Solar panel and battery wiring details are identified in the “Calibration
& System Details” section of this manual.
The battery should be wired to the Sensus “batt” connector.
2.7.2 Direct Landline Connected Systems
Direct landline systems use a single multi-core cable (Part number W4/1602/4)
to supply both 24 V DC power and communication signals to a remotely located
automatic weather station system. For such systems, a land-line interface
module (Part number 142009C) is supplied and this is generally located adjacent
to the display P.C.
Long distance communications are achieved using RS485 with a
suitable cable (typically Screened, 4 to 6 core 16 x 0.2 mm conductors). A local
power supply may be required to achieve distances up to approximately 2 km.
Landline wiring details of the Sensus logger and Interface unit are
contained in the “Calibration & System Details” section of this handbook.
The landline cable must be protected from potential damage by
locating it in conduit, burying it in a sand filled trench or using a suitable steel,
plastic or concrete cable duct.
The landline enters the main enclosure via a cable gland and all
connections to the system are made via quick-connect terminal plugs. Within the
office, the line is terminated to the office interface module. For systems
incorporating a non-standard or customer supplied landline, it is essential to
ensure that the landline interconnects correctly with the appropriate terminals of
the Sensus logger and landline interface.
WARNING !
Please refer to the land line power supply wiring drawing.
Always disconnect battery fuses when working on the system
wiring.
The supplied 9-way RS232 communications lead is used to interconnect the
landline interface to the to the RS232 port of a P.C. (A 9-to-25 way adaptor
may be required). A small wall mounted universal input mains power supply
interconnects to the Landline interface and supplies power to the remote
system.
The backup battery supplied with direct landline systems is a 12 Volt
7 Ah lead-acid type. This enables the logger to continue collecting data during
mains power failures. The backup time depends upon the initial charge state of
the battery and the total current consumption of the system, where the
consumption is influenced by the number and type of sensors.
The battery takes 2-3 days to reach a fully charged state. A fully
charged battery will backup a typical system having Rainfall, Wind speed,
Page 14 of 34
Automatic Weather Station
Assembly & Commissioning Handbook