Model TT231-0600
Two-Wire RTD Transmitter w/USB
Acromag, Inc. Tel: 248-295-0880
- 10 - http://www.acromag.com
- 10 -
http://www.acromag.com
Output/Power
Connections…
This model includes two extra terminal connections at TB4 marked “C” which
provide a convenient wiring point for a “sourcing” wiring variation as shown
below. Internally, these two terminals are connected in common with each
other and do not connect to the internal circuit. Use of these terminals in
your wiring scheme allows you to connect external power local to the
transmitter and form a “sourcing” entity from this “sinking” output as shown.
Earth Ground Connections
The unit housing is plastic and does not require an earth ground connection. If the
transmitter is mounted in a metal housing, a ground wire connection is typically
required and you should connect that metal enclosure’s ground terminal (green
screw) to earth ground using suitable wire per applicable codes. See the Electrical
Connections Drawing for Output/Power and note the traditional position of earth
ground for the two-wire output current loop. The Type II transmitter output
terminals have a floating connection relative to earth ground. Earth ground is
normally applied at the output loop power minus terminal and in common with the
loop load or loop receiver minus.
Do not earth ground any input lead and use only insulated/non-grounded RTD
sensors. This transmitter does not isolate its input signal.
Respect the traditional position of earth ground in a two-wire current loop and
avoid inadvertent connections to earth ground at other points, which would
drive ground loops and negatively affect operation. This includes a USB
connection to the transmitter, which should be made via a USB isolator, as
most Personal Computers earth ground their USB ports and this makes contact
with both the USB signal and shield grounds.
INPUT SIDE
OUTPUT SIDE
MODEL TT231-0600
MODEL TT231-0600 OPTIONAL OUTPUT WIRING
OUTPUT
TERMINALS
+
-
COMMON
C
C
TB3
TB4
TOP VIEW
(OUTPUT SIDE)
+
-
6
5
6
5
7
8
8
7
OPTIONAL "SOURCING OUTPUT" CONNECTIONS WITH
LOCAL EXTERNAL 3-WIRE POWER FORM
A SOURCING OUTPUT RELATIVE TO THE
LOOP+
LOOP-
OPTIONAL COMMON CONNECTIONS WITH
TB4
TB3
+
24VDC
+
-
LOCAL 24VDC
-
POWER SUPPLY
R
I
+
-
LOAD
REMOTE RECEIVER/LOAD
+
-
TWISTED PAIR
C
C
TERMINALS
I
I
I
I
I
I
POWER LOCAL TO TRANSMITTER
REMOTE SINKING LOAD.