Rosemount 3244MV, Справочное руководство

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Reference Manual
00809-0100-4799, Rev BA
September 2002
Model 3244MV
2-8
Grounding
Transmitters are electrically isolated to 500 V ac rms. Ground the signal
wiring at any single point, if desired. When using a grounded thermocouple,
the grounded junction serves as this point.
NOTE
Do not ground the signal wire at both ends.
Shielded Wire
Recommended grounding techniques for shielded wire usually call for a
single grounding point for each shielded wire to avoid grounding the loop. The
following two examples employ the single point grounding technique:
Example 1
1. Connect the signal wiring shield to the sensor wiring shield.
2. Ensure that the two shields are tied together and electrically isolated
from the transmitter housing.
3. Ground the shield at power supply end.
Example 2
1. Connect the sensor wiring shield to the ground terminal (located
inside the terminal compartment of the transmitter housing).
2. Cut the signal wiring shield and isolate from the transmitter housing.
3. Grounded the shield at the power supply end only. Never connect the
shield for the signal wiring to the ground terminal inside the
transmitter housing.
Transmitter Housing
Ground the transmitter housing in accordance with local electrical
requirements. The internal ground terminal is standard. An optional external
ground lug assembly (option code G1) can also be ordered if needed. This
external grounding method is recommended when using the optional transient
protector (option code T1).
Surges/Transients
The transmitter will withstand electrical transients usually encountered in
static discharges or induced switching transients. However, high-energy
transients, such as those induced in wiring from nearby lightning strikes, can
damage both the transmitter and the sensor.
A transient protection will be available at a later date for adding to the Model
3244MV with Profibus-PA.