IM_1XTXSW-08
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6
The One Series enclosure includes two conduit openings, one intended for the
high-power switch wiring and the other intended for low-level signal and analog
4-20 mA wiring. 4-20 mA signals shall be wired using a shielded/twisted pair to
minimize the effects of electrical interference. Please follow local electrical code
requirements for explosion/flame proof instrumentation.
Figures 4, 6, & 7 provide a rear view of the display module after it has been
removed from the base enclosure and an inside view of the base enclosure cir-
cuit boards. Terminal Block 1 (TB1) is located on the display module. Terminal
blocks TB2 & TB3 are located inside the base enclosure.*
Models 1XTXSW and 1XTX00 are loop-powered and are normally connected
directly to an analog input of a PLC or DCS via TB1 providing a 4-20 mA analog
signal, repeating the pressure or temperature process variable (see Figure 6,
Page 7). Polarity must be observed. This loop connection powers the entire
One Series, including the actuation of both solid-state relays (SW1 & SW2) and
the IAW
®
OUTPUT signal. The bi-directional relays are connected via TB2 and
are intended to switch external loads. IAW
®
OUTPUT is a discrete signal for
providing health status to a control system and is connected via TB3 and polar-
ity must be observed. Connections to the relays and the health status signal are
optional (not required).*
NOTE:
As an alternative to loop power, model 1XTXSW may be wired directly to
a 24 VDC power supply (+) and minus (-) terminals (see Figure 7, Page 7). In
this wiring configuration, power is provided for all switching and diagnostic func-
tions but the 4-20 mA analog output is not used. The digital display will provide
the process variable. This alternative method of powering the One Series may
be used when loop power is not available and a 4-20 mA output is not desired.
An additional discrete signal is available at TB3-1 & TB3-2. IAW
®
OUTPUT is
intended for monitoring the health status of the One Series by connecting it
to a logic solver input. This output may also be used to distinguish between
a process upset (set point reached) or the IAW™ self-diagnostics detecting
a fault. IAW
®
OUTPUT is normally-closed and opens if a fault is detected or if
power fails.*
NOTE:
Do not exceed the maximum switch ratings of the SW1, SW2, or IAW™
Output and signals or permanent damage to the One Series may result. Please
refer to Table 3 below.
TB 2
+
TB3
TB 2
TB2
3
3
SW1
SW2
TB3
+
TB3
+
-
RED
TB1
Maximum Switch Ratings
Signal Name
Location
Voltage Ratings
Current Ratings
SW1
TB2 (no polarity)
0 – 280 VAC and VDC
0.3 amperes
1
SW2
TB2 (no polarity)
0 – 280 VAC and VDC
0.3 amperes
1
IAW
®
OUTPUT
TB3-2 (+) & TB3-1 (-)
0 – 30 VDC
0.020 amperes
1
Derate 8% per 10 °C above 21°C
*Model 1XTXSW Only
WIRING DIAGRAMS
*
*
Figure 4
Figure 5
Table 3
