Samoa NEXU Manual Instalación página 18

EN
3. INSTALLATION AND CABLING
Contact probe inputs (Signal / Warning / Stop)
These three inputs allow connecting up to three contact probes (float
type or equivalent).
Each input has a different logic meaning:
S1 – IN 1 (SIGNAL): changes the stock level indicated in both the
display and the graph bar.
S2 – IN 2 (WARNING): triggers the warning level into the system and
turns into yellow colour the graph bar.
S3 – IN 3 (STOP): triggers the stop level into the system, turns into red
colour the graph bar and gives power to the External Alarm Input.
Also, it is possible to use only one or two contact probes: if only one probe
is used, it must be connected to S3 (STOP) input; if only two probes are
used, they must be connected to S2 (WARNING) and S3 (STOP).
NOTE: Analogue and contact probes cannot be used simultaneously into
the same tank.
This input allows connecting an analogue level probe in order to get in
real time an exact measurement of the fluid level inside the tank.
Currently, only barometric level probes Samoa code 382120)
are supported.
The probe must be connected as follows (red to +24V, black to IN, shield
to GND; leaving +12V disconnected).
NOTE: Analogue and contact probes cannot be used simultaneously into
the same tank.
Overfill input/output
This input allows connecting a safety contact probe (float type or
equivalent). Only normally-closed (NC, the electrical contact inside the
probe must stay closed when the fluid level is below the probe) switch-
type probes can be used.
This input, together with the overfill valve output, is meant as a safety
device to prevent overfilling the tank. By setting the overfill probe at the
maximum allowed fluid level inside the tank (full tank level), it stops the
fluid from entering the tank as soon as the overfill level probe is reached.
NOTE: this input/output is independent from the system, does not
require any setup, and will not trigger any warning into the system. In
can be used together with both analogue and contact probes.
OUTPUT LOGIC:
• Active (24VDC OUT) when the fluid reaches the overfill probe
• Inactive (0VDC OUT) when the fluid is below the contact probe.
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838 861 R. 06/21
SAMOA Industrial, S.A. · Pol. Ind. Porceyo, I-14 · Camino del Fontán, 831 · 33392 - Gijón - Spain · Tel.: +34 985 381 488 · www.samoaindustrial.com
Note that the three probes must be set at different heights depending on
the type of tank being monitored (fresh fluid tank or waste fluid tank):
S1
S2
S3
Fresh fluid
tank
Pump control output
This output allows controlling the compressed air supply to the pump
associated with this tank: when there is an active transaction that requires
fluid from the tank, the pump is supplied with compressed air in order to
make it work; and when there is no active transaction requiring fluid from
this tank, the pump does not get any compressed air supply and,
therefore, is depressurized.
This helps to minimize compressed air leaks and reduces the physical
stress of the pump.
S3
S2
S1
Waste fluid
tank