GHM Delta OHM LPPYRA03 User manual

Operating manual
Pyranometer
LPPYRA03
www.deltaohm.com
English
Keep for future reference.

LPPYRA03 - 2 - V2.8
TABLE OF CONTENTS
1 INTRODUCTION .................................................................................................... 3
2 WORKING RINCI LE ........................................................................................... 4
3 INSTALLATION ..................................................................................................... 5
4 ELECTRICAL CONNECTIONS .................................................................................. 8
4.1 LPPYRA03 CONNECTIONS ..................................................................................... 8
4.2 LPPYRA03AC CONNECTIONS .................................................................................. 9
4.3 LPPYRA03AV CONNECTIONS .................................................................................. 9
4.4 LPPYRA03S CONNECTIONS .................................................................................. 10
4.5 LPPYRA03S12 CONNECTIONS .............................................................................. 11
4.6 LPPYRA03ACS CONNECTIONS .............................................................................. 12
5 MEASUREMENT IN THE MODELS WITH ANALOG OUT UT .................................... 13
5.1 LPPYRA03 ..................................................................................................... 13
5.2 LPPYRA03AC[S] ............................................................................................. 13
5.3 LPPYRA03AV ................................................................................................. 13
6 RS485 MODBUS-RTU OUT UT ............................................................................. 14
6.1 SETTING THE COMMUNICATION PARAMETERS ............................................................... 14
6.2 REA ING THE MEASURES WITH THE MO BUS-RTU PROTOCOL .......................................... 16
7 SDI-12 OUT UT .................................................................................................. 17
8 MAINTENANCE .................................................................................................... 21
9 TECHNICAL S ECIFICATIONS ............................................................................. 22
10 SAFETY INSTRUCTIONS ...................................................................................... 23
11 ORDERING CODES .............................................................................................. 24

LPPYRA03 - 3 - V2.8
1 INTRODUCTION
LPPYRA03 pyranometer measures the irradiance on a flat surface (W/m2). The meas-
ured irradiance (Global Irradiance) is the sum of direct solar irradiance and diffuse ir-
radiance.
LPPYRA03 is a Spectrally Flat Class C (Second Class) pyranometer in accordance with
ISO 9060:2018 and with the criteria of the WMO “Guide to Meteorological Instruments
and Methods of Observation’”.
The pyranometer is available in the following versions:
•L YRA03: PASSIVE.
The passive version can be connected to the instruments
09847 and H 31 by using VP 472 SICRAM module.
•L YRA03AC: ACTIVE with 4..20 mA CURRENT output (0…2000 W/m2).
•L YRA03ACS: ACTIVE with 4..20 mA CURRENT output (0…2000 W/m2) and
RS485 Modbus-RTU output.
•L YRA03AV: ACTIVE with 0..1 or 0..5 or 0..10 V VOLTAGE output
(0…2000 W/m2) to be defined when ordering.
•L YRA03S: With RS485 Modbus-RTU output.
•L YRA03S12: With S I-12 output.
The pyranometer is supplied factory calibrated and with a calibration report. The
calibration is carried out in accordance with the ISO 9847:1992 (type IIc) standard:
”Calibration of field pyranometers by comparison to a reference pyranometer”. The
pyranometer is calibrated by comparison with the reference sample calibrated
annually at WRC (World Radiation Center).

LPPYRA03 - 4 - V2.8
2WORKING RINCI LE
LPPYRA03 pyranometer is based on a thermopile sensor. The thermopile sensitive sur-
face is coated with a black matt paint, which allows the pyranometer not to be selec-
tive at different wavelengths. The pyranometer spectral range is determined by the
transmission of the glass dome type K5.
Radiant energy is absorbed by the thermopile black surface, thus creating a difference
of temperature between the center of the thermopile (hot junction) and the pyranom-
eter body (cold junction). Thanks to the Seebeck effect, the difference of temperature
between hot and cold junction is converted into a ifference of Potential.
In order to grant the thermopile a proper thermal insulation from the wind and reduce
the sensitivity to thermal irradiance, LPPYRA03 is equipped with a 4 mm thick dome
which is 32 mm in outer diameter. The dome protects the thermopile from the dust,
which might change spectral sensitivity if it lies on the black surface,
To prevent internal condensation forming on the internal side of the dome under cer-
tain climatic conditions, silica gel tablets are inserted inside the pyranometer to ab-
sorb humidity.
Fig. 2.1: scheme of principle L YRA03 (version with mV output)
T
h
ermopil
e
Connector pins
Housing

LPPYRA03 - 5 - V2.8
3INSTALLATION
•The pyranometer must be mounted in an easy-to-reach location in order to clean
the dome regularly and carry out maintenance. At the same time, make sure that
no buildings, constructions, trees or obstructions exceed the horizontal plane where
the pyranometer lies. If this is not possible, select a site where obstructions in the
path of the sun from sunrise to sunset do not exceed 5 degrees of elevation. N.B.:
The presence of obstructions on the horizon line affects significantly the
measurement of direct irradiance.
•The pyranometer must be located far from any kind of obstruction, which might re-
flect sunlight (or sun shadow) onto the pyranometer itself.
•In compliance with ISO TR9901 standard and WMO recommendations, when the
pyranometer is used without the optional shade disk, it must be positioned so that
its connector is pointed to the North Pole, if the instrument is used in the Northern
Hemisphere, and to the South Pole, if used in the Southern Hemisphere. In any
case, it is better to follow this suggestion even when the shade disk is applied.
•For fixing, use the holes on the pyranometer body or the suitable accessories (see
the figures below). In order to allow an accurate horizontal positioning, the pyra-
nometer is equipped with a levelling device. The mast height does not exceed the
pyranometer plane to avoid measurement errors caused by any reflection or shad-
ow of the mast itself.
•It is preferably to thermally insulate the pyranometer from its mounting bracket
ensuring, at the same time, a good electrical contact to ground.
61 mm 83 mm
LPPYRA03AC
LPPYRA03AV
LPPYRA03[AC]S
LPPYRA03S12
LPPYRA03
59 mm
46 mm
32 mm
24 mm
M4
32 mm
Fig. 3.1: fixing holes
M5
fixing hole
Fixing hole
for LP SP2

LPPYRA03 - 6 - V2.8
LPPYRA03AC
LPPYRA03AV
LPPYRA03[AC]S
LPPYRA03S12
+
LPS2
LPPYRA03
+
LPS2
LPPYRA03
+
HD2003.77/40
LPSP2
500 mm
16 mm
40 mm
LPPYRA03AC
LPPYRA03AV
LPPYRA03[AC]S
LPPYRA03S12
+
HD2003.77/40
D
HD9007
HD9007T29.1
C
A
B
TP32MTT.03.C
80° MAX
int.
M37 x 2
LPPYRA03
Fig. 3.2: fixing accessories

LPPYRA03 - 7 - V2.8
Fig. 3.3: fixing accessories

LPPYRA03 - 8 - V2.8
4ELECTRICAL CONNECTIONS
L YRA03, L YRA03AC and L YRA03AV have a 4-pole connector and use the
C M12AA4... optional cables, with 4-pole connector on one side and open wires on
the other side.
L YRA03S and L YRA03S12 have a 8-pole connector and use the C M12-8D...
optional cables, with 8-pole connector on one side and open wires on the other side.
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 LPPYRA03AV the housing is not con-
nected to the connector.
Inside the housing there is a surge protector connected between the
housing itself and the electronic circuit (powered models) or the ca-
ble shield (passive model). Grounding the housing allows the correct
protection function (in particular against lightning) of the surge pro-
tector.
4.1 L YRA03 CONNECTIONS
The pyranometer LPPYRA03 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 py-
ranometer output signal does not exceed 20 mV. In order to better exploit the pyra-
nometer features, the readout instrument should have 1 µV resolution.
Connector Function Color
1 +Vout Red
2 -Vout Blue
3 Housing (C) White
4 Cable shield (SH) Black
12
34
+Vout
-Vout
SH
C
Fig. 4.1: L YRA03 connections
CPM12AA4… cable
Pyranometer M12
male connector
atalogger 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
To circuit
Housing
Surge
protector

LPPYRA03 - 9 - V2.8
4.2 L YRA03AC CONNECTIONS
The pyranometer LPPYRA03AC has 4…20 mA output and requires 10…30 Vdc exter-
nal power supply. It is to be connected to a power supply and an instrument with
4…20 mA input as shown in fig. 4.2. The load resistance of the instrument reading the
signal must be ≤ 500 Ω.
Connector Function Color
1 Positive (Iin) Red
2 Negative (Iout) Blue
3 Housing (C) White
4 Cable shield (SH) Black
4...20 mA
12
34SH
Iin
Iout
C
Fig. 4.2: L YRA03AC connections
4.3 L YRA03AV CONNECTIONS
The pyranometer LPPYRA03AV has 0…1 V, 0…5 V or 0…10 V output (depending on
the ordered output) and requires external power supply: 10…30 Vdc for 0…1 V and
0…5 V outputs, 15…30 Vdc for 0…10 V output. It is to be connected to a power sup-
ply and an instrument with voltage input as shown in fig. 4.3. The load resistance of
the instrument reading the signal must be ≥ 100 kΩ.
Connector Function Color
1 Output positive (+Vout) Red
2 Output negative
Power supply negative (GN ) Blue
3 Power supply positive (+Vdc) White
4 Cable shield (SH) Black
12
34
SH
GND
+Vdc
+Vout
Fig. 4.3: L YRA03AV connections
CPM12AA4… cable
Pyranometer M12
male connector
Power supply
Connect to ground only if it is not possible to
ground locally the housing of the pyranometer
Instrument with
4…20 mA input
CPM12AA4… cable
Pyranometer M12
male connector
Power supply
Instrument
with
voltage input

LPPYRA03 - 10 - V2.8
4.4 L YRA03S CONNECTIONS
The pyranometer LPPYRA03S has RS485 Modbus-RTU output and requires
5…30 Vdc external power supply. It is to be connected to a power supply and to a
PLC, a data logger or a RS485/USB or RS485/RS232 converter for PC as shown in fig.
4.4. The RS485 output is not isolated.
Connector Function Color
1 Power supply negative (GN ) Blue
2 Power supply positive (+Vdc) Red
3 Not connected
4 RS485 A/- Brown
5 RS485 B/+ White
6 Housing / Cable shield (SH) Black
7 Not connected
8 Not connected
ShieldShield
Lmax = 1200m
B/+
A/-
12
3
456
7
8
B/+
A/-
SGND
+Vdc
GND
GND
+Vdc
A/-
B/+
SH
R
220
T
Ω
R
220
T
Ω
Fig. 4.4: L YRA03S connections
Before connecting the pyranometer to the RS485 network, set the address and the
communication parameters, if different from the factory preset (see chapter 6).
Power supply
CPM12-8 … cable
Pyranometer M12
male connector
PLC, data logger or
RS485/USB or
RS485/RS232
converter for PC
Other sensors with
RS485 output
Connect to ground only if it is not possible to
ground locally the housing of the pyranometer