Solar Irradiance - RainWise PVmet 500 Series User Manual

Extended Cable (m)
10
50
100
100

SOLAR IRRADIANCE

Solar irradiance is the primary measurements for the PVmet 500. There are 3 solar irradiance inputs. The maximum voltage output
allowed for solar irradiance sensors is 1.5V. The inputs are well protected against EMI/ESD but due to the low voltage signals from
solar irradiance sensors, they are highly sensitive. Care must be taken to route cabling away from electrically noisy equipment such as
power inverters and motors. The solar irradiance sensor must have a shielded wire. The shielded wire must not be connected at the
sensor end, it is to be terminated at the PVmet-500360° shield connection only as depicted in 20.
Due to the high input impedance of the solar irradiance inputs additional cable length should not cause a significant error, but keeping
cable runs as short as possible will help minimize error from noise.
Table 1: Example BOM temp corrections due to longer cables.
Temp (C°) Temp reported by station (C°)
25 25.041
25 25.205
25 25.41
40 40.41
Figure 20: Solar irradiance sensor shield connection
- 16 -
Correction to Add (C°)
-0.0041 × 10 = -0.041
-0.0041 × 50 = -0.205
-0.0041 × 100 = -0.41
-0.0041 × 100 = -0.41