AccUView LED (1/2020)
Rev 2
8
Figure 5: Electrical Connections for the Instrument
3.3.1 Power:
The instrument is equipped with a 100-240 VAC, 47-63 Hz switching power
supply; please verify that the line voltage falls within these specifications. It is
recommended that a circuit breaker be placed prior to the power connection to allow for
service. While making connections, refer to Figure 5.
The AccUView LED is not
supplied with a power cord
.
3.3.2 RS-485:
The RS-485 Modbus or special protocol half-duplex (2-wire) digital
interface operates with differential levels that are less susceptible to electrical
interferences. This is why cable lengths up to 3000 ft can be implemented. The last
device on each bus may require terminating with a 120-ohm resistor to eliminate signal
reflection on the line. Do not run RS-485 cables in the same conduit as power.
To prevent damage to the instrument, ensure that power is disconnected prior to making
connections. For ease of connecting, remove the plug in terminal block. Connections are
labeled beneath this termination.
3.3.3 Relays:
The Alarm 1 and Alarm 2 relays are mechanical relays rated at 240 VAC
2A. Please note that the relays are labeled NO (Normally Open), NC (Normally Closed)
and C (Common). As these alarms are configured fail-safe, the normal condition is with
power applied to the AccUView LED and in a non-alarm condition. Operation of these
alarms is covered in section 7.4
Configuring the Alarms
.
3.3.4 4-20 mA:
The 4-20 mA output is driven by a 15 VDC power source and can drive
recorder loads up to 600 ohms. Do not run 4-20 mA cables in the same conduit as power.
Operation of this output is covered in section 7.2
Setting the 4-20 mA
. The outputs are
equipped standard with an installed loop powered isolator (500V isolation).
To prevent damage to the instrument, ensure that power is disconnected prior to making
connections. For ease of connecting, remove the plug in terminal block. Polarity of the
connections is labeled beneath this termination.
