Wiring; Hazardous Locations; Grounding The Signal Wiring; Grounding The Proplate Case - Emerson Rosemount 1195 Installation And Operation Manual

Wiring

Hazardous Locations

Grounding the
Signal Wiring
Grounding the
ProPlate Case
To make connections, remove the housing cover on the side marked
FIELD TERMINALS. Do not remove the instrument covers in
explosive atmospheres when the circuit is alive. All power to the
ProPlate is supplied over the signal wiring. Connect the lead that
originates at the positive side of the power supply to the terminal
marked "+" and the lead that originates at the negative side of the
power supply to the terminal marked "–." Avoid contact with the leads
and terminals.
Inductive-based transient protectors, including the Model 470, can
adversely affect the output of the ProPlate. Do not use the Model 470
for transient protection with the ProPlate. If transient protection is
desired, install the Transient Protection Terminal Block. Consult the
factory for instructions.
The ProPlate has an explosion-proof housing and circuitry suitable for
intrinsically safe and non-incendive operation. Individual ProPlate
models are clearly marked with a tag indicating the certifications they
carry. See Section : Specifications and Reference Data for specific
approval categories.
NOTE
Signal wiring does not require shielding; however, twisted pairs provide
the best results. In order to ensure communication, wiring should be
24AWG or larger and shorter than 5,000 feet (1500 meters) in length.
Do not connect the powered signal wiring to the test terminals. Power
may damage the test diode in the test connection.
Plug and seal unused conduit connections on the electronics housing to
avoid moisture accumulation in the terminal side of the housing.
Excess moisture accumulation may damage the ProPlate electronics. If
the connections are not sealed, the ProPlate electronics should be
remote mounted with the electrical housing positioned downward for
drainage. Wiring should be installed with a drip loop, and the bottom of
the drip loop should be lower then the conduit connections and
the housing.
Do not run signal wiring in conduit or open trays with power wiring, or
near heavy electrical equipment. Signal wiring may be grounded at any
one point on the signal loop, or it may be left ungrounded. The negative
terminal of the power supply is a recommended grounding point.
The ProPlate should always be grounded in accordance with national
and local electrical codes. The most effective ProPlate case grounding
method is a direct connection to an earth ground with minimal
impedance. Methods for grounding the ProPlate case include:
• Internal Ground Connection: Inside the FIELD TERMINALS
side of the electronics housing is the Internal Ground Connection
screw, which is identified by a ground symbol:
NOTE
Grounding the electronics case via threaded conduit connection may
not provide sufficient ground.
.
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