LPPYRA-Lite
- 8 -
V1.2
4
ELECTRICAL CONNECTIONS
LPPYRA-Lite
has a 4-pole connector and uses the
CPM12AA4...
optional
cables.
The metallic housing of the pyranometer should preferably be
grounded ( ) locally. In this case, do not connect the wire of
the cable corresponding to the housing to prevent ground loops.
Only if it is not possible to ground locally the metallic case of the
pyranometer, connect the wire of the cable corresponding to the
housing to ground.
Note: in LPPYRA-LiteAC the housing is not con-
nected to the connector.
In the powered version LPPYRA-LiteAC, internally there are surge protection devices
connected to the housing. Grounding the housing allows the correct protection func-
tionality, in particular against lightning.
4.1
LPPYRA-Lite
CONNECTIONS
The pyranometer LPPYRA-Lite is passive and does not require power supply. It is to
be connected either to a millivoltmeter or to a data acquisition system. Typically, the
pyranometer output signal does not exceed 20 mV. In order to better exploit the py-
ranometer features, the readout instrument should have 1
µ
V resolution.
Connector
Function
Color
1
+Vout
Red
2
-Vout
Blue
3
Not connected
White
4
Cable shield (SH) / Housing
Black
1
2
3
4
+Vout
-Vout
SH
Fig. 4.1: LPPYRA-Lite connections
CPM12AA4… cable
Pyranometer M12
male connector
Datalogger or
converter/amplifier
with
V
or
mA
output
Connect to ground only if it is not possible to
ground locally the housing of the pyranometer