Emerson Rosemount 1152 Alphaline, Справочное руководство

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Reference Manual
00809-0100-4235, Rev BA
April 2007
Rosemount 1152
2-6
Figure 2-3. Transmitter Installation Configurations.
Conduit
The conduit connections to the transmitter are ½–14 NPT. Two hubs are
available on the transmitter for convenient installation. Close off the unused
hub with a stainless steel ½–14 NPT pipe plug; all threads must be sealed
with a pipe-thread sealant. Use a qualified conduit seal at the conduit entry to
prevent moisture from accumulating in the terminal side of the housing during
accident conditions. To prevent the conduit from adding mechanical stress to
the transmitter during seismic disturbances, use flexible conduit or support
the conduit near the transmitter. Install the conduit seal in accordance with the
manufacturer’s instructions or use the procedure on page 2-8.
ELECTRICAL
CONSIDERATIONS
This section contains information that you should consider when preparing to
make electrical connections to the transmitter. Read this section carefully
before proceeding to the electrical installation.
The Rosemount 1152 Pressure Transmitter provides a 4–20 or 10–50 mA
signal when connected to a suitable dc power source. Figure 2-4 on page 2-7
shows a typical signal loop consisting of a transmitter, a power supply, and
various receivers (controller, indicator, computer, etc.). With 4–20 mA output
electronics, the power supply must supply at least
12 volts to the transmitter terminals at 30 mA (overscale) signal, or the
maximum output current required for proper system operation. With 10–50
mA output electronics, the power supply must provide 30 volts minimum to
the transmitter terminals at 90 mA (overscale) signal, or the maximum output
current required for proper system operation. Any power supply ripple
appears in the output load. The supply voltage versus load limitation
relationship is shown in Figure 2-5 on page 2-7. The load is the sum of the
resistance of the signal leads and the load resistance of the receivers.
Signal wiring need not be shielded, but twisted pairs yield the best results. In
electrically noisy environments, shielded cable should be used for best
results. Do not run signal wiring in conduit or open trays with power wiring, or
near heavy electrical equipment. Signal wiring may be ungrounded (floating)
or grounded at any place in the signal loop. The transmitter case may be
grounded or ungrounded.
Blocking Valves
Flow
3-Valve Manifold
Plugged Tees for
Steam Service or
Sealing Fluid
Drain/Vent
Valves
Sufficient
Length
for Cooling
Rosemount 1152DP, HP
Plugged Tee for
Steam Service or
Sealing Fluid
Blocking
Valve
Drain/Vent
Valve
Sufficient
Length
for Cooling
Rosemount 1152AP, GP
Drain/Vent
Valves Drain/Vent
Valve
3-Valve
Manifold
Flow
Rosemount 1152DP, HP
Rosemount 1152AP, GP
LIQUID SERVICE
GAS SERVICE
L
H
H
L
Sufficient
Length
for Cooling