UE ONE Series, Installation & Maintenance Instructions Manual

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3
The positive side of the load is connected to the load power
source V
l
+. See Diagram 8.
NOTE:
If the switched output load is inductive (i.e. a relay),
a fly back diode, such as a 1N914 should be used to prevent
an inductive feedback into the switched output circuit. See
Diagram 9.
LOGIC SOLVER CONNECTION
The One Series' 100 mA switched output may also be
connected to a digital input channel on a logic solver. An
appropriately sized pull-up resistor must be connected
between the digital input and a DC power source. The value
of the pull-up resistor must be calculated based on the
excitation voltage and the voltage threshold for a logic level
low required by the logic solver. The off-state leakage
current of 10
µ
A must be factored into the equation. See
Diagram 10.
Solid State Relay Switched Output
(Output Type C)
The One Series SSR switched output is a single pole, single
throw (SPST) switching device which makes and breaks the
output circuit. Two terminals are provided for the external
load power source
(VAC-HI) and the switched signal connected to the device
under control (LOAD). Wire the output as follows, per
Diagram 11.
•
The power source connects to the terminal marked
VAC-HI
•
The load connects to the terminal marked LOAD
•
The other load connection is to the power source return
Optional 4-20 mA Analog Process
Signal Output
The One Series 4-20 mA output signal is intended for
remote monitoring or trending of the process variable. The
output is a sourcing (powered) output which simply means,
no external power supply should be applied to this
connection.
The current loop begins with the output connection, through
the remote indicator or controller (500
Ω
max.) terminating at
the One Series circuit common connection. See Diagram
12.
The positive (+) lead of the output device is connected to the
Ones Series, 4-20 mA output connection.
For Model A, this would be the Yellow, 20 AWG
wire.
For Models B & C, the terminal is marked 4 - 20
mA.
The Negative (-) lead of the output device must return to the
One Series circuit common connection.
The One Series 4 to 20 mA output may also be connected
to a logic solver. See Diagram 13.
Summary of Wiring Connections
The following tables show the output function and the
corresponding connection on the product.