Eaton F880 redundant fieldbus power for Yokogawa CENTUM 3000 R3 Control System

• Integrated redundant fieldbus power for ALF111 Foundation™ fieldbus cards

• 8-segment redundancy

• High-density, compact design

• Fully isolated

• Hot swappable power modules*

• Low power dissipation

• Zero component carrier

• On-line diagnostics option

• Redundant power & conditioning

• Vertical DIN-rail mounting

• F801 output 21.5V, 350mA

• F802 output 28V, 500mA

The F880 fieldbus power system is designed to provide redundant power for

eight Foundation™ fieldbus H1 segments when used with Yokogawa ALF111

fieldbus cards. The F880 module carrier has system connectors for direct

connection to two redundant pairs of fieldbus cards using Yokogawa AKB336

cables.

Power for the fieldbus segments is provided by two power modules - F801s

or F802s - operating in a redundant configuration (loadsharing).

Failure alarms, galvanic isolation, power conditioning and segment termination

are incorporated into each F80x module. In simplex applications, a single F80x

module may be used. Termination of the fieldbus segments is automatically

maintained when single or redundant F80x modules are fitted.

For extreme reliability, the module carrier has no components and only provides

interconnections between the power modules and external connections.

It is supported in a rigid metal frame that protects the circuit board from

mechanical damage. Secure DIN rail mounting is provided by integrated fixings.

Each F80x module monitors the output of the eight fieldbus segments and

indicates an alarm, by means of a built-in, normally closed relay, if any of

the segments is shorted or below the minimum output voltage threshold.

Failure of either of the bulk power input supplies is also annunciated.

The alarm contacts are volt-free and galvanically isolated from other circuitry.

Connections to the alarm relays are made via terminals on the F880-Cx carrier.

A separate alarm module is not required for this function.

LED indicators also show the status of each F80x module and the eight individual

segments. In normal operation, each segment LED is lit, showing that the segment

is powered. If a segment is shorted, this LED is extinguished, and the module

Alarm LED is lit.

A separate physical layer diagnostics module may be installed on the carrier to

automatically collect and distribute additional diagnostic information for each of

the eight fieldbus segments. 

The F80x module provides galvanicisolation between the 24V DC input power

and the fieldbus segments, as required by the IEC61158-2 fieldbus standard

and the Fieldbus Foundation™ FF-831 validation test for fieldbus power

supplies. There is also galvanic isolation between the fieldbus segments,

thereby preventing multiple segment failures due to ground faults on more

than one segment.

Each segment has its own fieldbus power conditioner and current limitation.

Redundant 24V DC (nom.) input power is connected to the F880 carrier using

two part pluggable connectors. Field wiring connections are available with either

pluggable screw terminals (F880-xS) or pluggable spring clamp terminals

(F880-xC).

Three variants of carriers are available in the F880 family. The F880-CA-Px carrier

provides terminal numbering and consistent connector polarity.

Where two columns of F880-CA-Px are installed in a cabinet the carrier is rotated

by 180 degrees for installation in the second column. Alternatively, if there is a

requirement for cabinet wiring to be symmetrical, there are lefthand (F880-CL-Px)

and righthand (F880 CR-Px) versions.