N1540
NOVUS AUTOMATION
3
The USB interface IS NOT SEPARATE from the
signal input (PV) or the digital inputs and outputs.
It is intended for temporary use during
CONFIGURATION and MONITORING periods.
For the safety of people and equipment, it must
only be used when the equipment is completely
disconnected from the input/output signals.
Using the USB in any other type of connection is
possible but requires a careful analysis by the
person responsible for installing it.
When MONITORING for extended periods of time
and with connected inputs and outputs, we
recommend using the RS485 interface, which is
available or optional in most of our products.
PV RETRANSMISSION
The digital panel meter may include an analog output which performs
the retransmission of the measured process variable (PV) values.
The analog retransmission can be scaled, i.e., there are minimum
and maximum limits to establish the retransmission range, defined in
the
rtLL
and
rtkL
parameters.
The digital panel meter allows a ratio between indication range and
output current with inversely proportional behavior (
rtll
>
rtKL
).
The analog output is available on terminals 18 (+) and 19 (-) for
N1540-RT
and
N1540-RT-24V
models.
The user sets the relay signal between 0 to 20 mA and 4 to 20 mA.
To obtain retransmission at an electrical voltage of 0 to 10 V, the
user shall install a shunt resistor (500
Ω
max.) across the analog
output terminals and select the 0 to 20 mA signal as the electrical
relay signal.
The analog retransmission output is electrically isolated the other
circuits.
Figure 2 –
PV retransmission terminals (RT mA OUT)
Note:
RS485 Communication and PV Retransmission features are
mutually exclusive.
INSTALLATION / CONNECTIONS
The digital panel meter is meant for panel mounting. The sequence of
steps is:
•
Prepare a cut-out of 93.0 by 45.5 mm on the panel.
•
Remove the mounting clamp from the digital panel meter.
•
Insert the digital panel meter into the cut-out from the front side of
the panel.
•
Place the clamp on the digital panel meter again, pressing until
firm grip to the panel.
ELECTRICAL CONNECTIONS
The terminals configurations are shown in
Figure 3
:
Figure 3 –
Inputs connections and power supply
It is necessary to observe the existence of polarity in the connection
of power supply line in 24 V models: Terminal 18 = (+) and terminal
19 = (-).
Figure 4 –
Thermocouple, Pt100, and 50 mV signal connection
Figure 5 –
Current (mA) and Voltage (V) signal connection
This digital panel meter offers an auxiliary 24 Vdc power supply which
is typically applied to power up 2-wire 4-20 mA field transmitters. The
Figure 6
presents the wiring for this application:
Figure 6 –
24 Vdc source with a 2-wire transmitter (passive, Sink
type)
INSTALLATION RECOMMENDATIONS
•
To minimize the pick-up of electrical noise, the low voltage DC
connections and the sensor input wiring should be routed away
from high-current power conductors. If this is impractical, use
shielded cables. In general, keep cable lengths to a minimum.
•
The input signals conductors shall be positioned throughout the
factory separate from the output and the power supply
conductors, in grounded conduits if possible.
•
The power supply of the electronic instruments shall come from a
proper source for the instrumentation network.
•
It is recommended to use RC FILTERS (0,1 uF in series with 100
ohms) to suppress the noise generated by contactors coils,
solenoids, etc.
