Siemens ET 77E Series Especificaciones descargar pdf (Pagina 27)

SD77

FIGURE 2-6 Terminal Enclosure

2.7 SHIPPING AND RESTRICTION SCREWS

The transducer has a shipping screw in the center of the top housing to protect the transducer's nozzle during

shipment. A restriction screw (stamped R) is located just behind the shipping screw. These two screws must be

interchanged before placing the instrument into operation. Turn the restriction screw in tightly for proper operation.

Note that if the transducer is to be moved to another location, return the shipping and restriction screws to their

original positions to protect the nozzle. See Figure 2-1 for the positions.

2.8 WIRING

Connect electrical wiring to the terminal block in the terminal enclosure. Figure 2-1 locates the terminal access

cover and the 1/2" conduit connector for input wiring. Figure 2-6 identifies the wiring connections. As shipped from

the factory, the conduit connection is a vent path for the transducer's exhaust. Refer to the Exhaust Port Selection

section if airtight conduit or fittings are to be used.

For a transducer with the optional reverse acting output (e.g., Model 77-16R), the input wiring must be reversed (i.e.

positive to negative and negative to positive).

The recommended wire size is 22 AWG (0.38 mm

) stranded or solid. Use insulated, crimp-on ring tongue or spring

spade tongue terminals for #6 screws. Use a high quality crimping tool recommended by the terminal manufacturer.

No special considerations are required for wiring a non-intrinsically safe transducer. However, intrinsically safe

models must be installed as detailed in the next section.

Note

When the transducer is used with a Siemens or Moore Products, Co. Model 348 FIELDPAC™

that employs HART communications, a Communications Filter should be connected across the

wiring terminals. Contact the Process Instrumentation & Analytics Business Unit of Siemens

Industry, Inc. for additional information and filter availability.

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Siemens ET 77E Series Especificaciones Pagina 27