OPERATING MANUAL
MN-SST70
ED-19-01
SPRIANO® TECHNOLOGIES
- www.spriano.it – [email protected]
a TERRANOVA® Srl brand
- www.terranova-instruments.com - VAT IT07848810151
Factory & Sales: Via Gramsci 1 – 26827 Terranova dei Passerini (LO) – Italy
Head Office: Via Rosso Medardo 16 – 20159 Milano – Italy Ph: +39 0377 919119 – Fax: +39 0377 855720
Pa
g.
15
/52
3.8
E
LECTRICAL
C
ONNECTION
Under the rear cap are placed the terminals reporting the electric polarity (
Insert the power supply cable into the enclosure through one of the two threaded openings.
Transmitter is protected from accidental inversion of polarity. For a better use is recommended
a twisted pair cable (22 AWG min). Avoid placing Transmitter near devices powered in AC or
Switching. Connect ground-tap of the Transmitter to the local common earth (PE) as indicated
in 3.10
W
ARNING
!
The threaded opening that is not used must be sealed using a suitable cap.
The caps included in the delivery are only for protection during transport.
Figure 9: electrical connection
I
NFORMATION
!
Impedance of the cables defines the
possible maximum length for digital
communication.
It's recommended using cable with a low impedance. The
maximum length of the point to point connection, with a load
of 250 ohm and
single twisted cable 22 AWG-207 pF/m it's
about 1000 meters.
The maximum connection length for the analog signal only is
limited by the loads
(connected devices and cable) present
in the current loop.
To obtain output signal of 4-20 mA, you have to determine the minimum supply voltage as a
function of the load relation: see
. From the following formula you can achieve the
right minimum value of supply voltage:
V
dc
= 0.0215 x R
L
+ 12
Where:
R
L
= output load [Ohm].
The power supply source to assure a minimum current value of 24 mA.
Loop
4-20 mA
Loop 4-20 mA
For remote local
indicator SST70-REM
(OPTIONAL)
Ground
