Electrical Installation; Transmitter Wiring Detail - Emerson Rosemount 1181pH TRANSMITTER Instruction Manual

MODEL 1181 pH/ORP
2.3 ELECTRICAL INSTALLATION. The transmitter
has two ¼-inch conduit openings, one on each side of
the housing. One opening is for the power or signal
wiring, and the other is for the input wiring from the
sensor.
On models with the meter, make sure the
meter wiring is securely connected after
the signal and input wiring have been
attached.
2.3.1 Sensor input wiring terminals are located on the
side of the housing designated TERM SIDE on the
serial label, and are the lower set of terminals (TB2).
Remove the end cap from the TERM SIDE of the hous-
ing to gain access to the terminals (see Figure 2-2).
If the Model1181pH/ORP transmitter has been sup-
plied with an integral preamplifier (Code Preamp
Options 43 or 44), please refer to Figure 2-3 Integral
Preamp Installation, and Figure 2-4 Wiring Details
Integral Preamp for sensor input wiring instructions.
2.3.2 Power and signal wiring terminals are located
directly above the sensor input wiring terminals and
are designated TBl. For models with a meter, the ter-
minals leads are also attached to TBl.
2.3.3. Conduit connection on the transmitter housing
should be sealed or plugged (using a sealing com-
pound) to avoid accumulation of moisture in housing. If
the connections are not sealed, the transmitter should
be mounted with the electrical housing downward for
draining.
TB1-1 Loop Signal (Power Supply + Vdc)
TB1-2 Meter (+) Red
TB1-3 Meter (–) Black & Loop Signal (4-20 mA Output)
TB2-1 pH/ORP Signal (Black)
TB2-2 Reference (Shield) & TC (Red)
TB2-3 Preamp (+5V, White)
TB2-4 Preamp (–5V, Green)
6
NOTE
FIGURE 2-2. Transmitter Wiring Detail
2.3.4. The transmitter case shall be grounded. Power
supply regulation is not critical. Even with the power
supply ripple, of one volt peak to peak, the ripple in the
output signal would be negligible.
For best EMI/RFI protection, the power sup-
ply/signal cable must be shielded and placed
in an earth grounded, rigid metal conduit.
Connect the outer shield to the earth ground
terminal provided next to TB1.
The sensor cable should also be shielded.
Connect the sensor cable's outer shield to the
transmitter's earth ground via the ground ter-
minal next to TB1. If the sensor cable's outer
shield is braided an appropriate metal cable
gland fitting may be used to connect the braid
to earth ground via the instrument case.
A new addition to the suite of tests done to
ensure CE compliance is IEC 1000-4-5. This is
a surge immunity test that simulates overvolt-
ages due to switching and lightning transients.
In order to meet the requirements of this test,
additional protection must be added to the
instrument in the form of a Transient Protector
such as the Rosemount Model 470D. This is a
3½-inch tube with ½-inch MNPT threads on
both ends. Inside the tube are gas discharge
and zener diode devices to limit surges to the
transmitter from the current loop. No additional
protection is needed on the sensor connec-
tions.
SECTION 2.0
INSTALLATION
NOTE