DAVIS Vantage Pro2 with Fan/Shield - Manual (Page 5)

Fan-Aspirated Shield Maintenance
5
• Use only one fan battery for some overnight aspiration but with slightly
higher average daytime aspiration.
• Remove both batteries for maximum daytime aspiration and no nighttime
aspiration. See “Replacing Fan Motor and Batteries” on page 6 for more
information.
Fan-Aspirated Shield Maintenance
• Keep the outer surfaces clean, since the unit is less effective when the sur-
faces are dirty. Remove dust from the solar panel and the shield with a
damp cloth. Pull off and clean the inlet screen as necessary.
• Remove any debris obstructing air flow through the radiation shield, e.g.,
leaves, twigs, webs, and nests.
• Avoid spraying insect killer of any kind into the radiation shield as this may
damage the sensors and the shield.
• Disassemble the shield and clean interior surfaces as necessary to prevent
dirt build-up. Consider replacing the motor (Part # 7758) and batteries
every two to three years.
• To check the motor, listen for the slight whirring or, on a calm day, test air
suction by placing a very thin one-ply piece of plastic the size of the fan
screen at the bottom of the radiation shield. If the fan is working, the plastic
will stick to the fan screen.
Note: The fan runs at low speeds in order to conserve limited solar and battery capacity. The fan motor
turns faster on solar power and slower on battery power. For instance, if the fan motor’s strength
is tested when it is running on optimal solar power, testing the fan with a piece of plastic is easy.
Testing on battery power alone requires more care because air movement is less.
Disassembling the Radiation Shield
Disassemble the radiation shield for routine
cleaning, maintenance, and to replace the
batteries and motor. To disassemble the
shield:
1. Remove the three screws connecting the
rain collector base to the threaded
spacers.
2. Lift the rain collector base off of the
threaded spacers. For easier re-assembly,
mark the holes used by the rain collector
base, the holes used by the radiation
shield, and the orientation of the bracket
relative to the radiation shield.
1-1/4" Screw
Rain Collector Base
Threaded
Spacer
Lock Washer
Flat Washer