Alarms; Isolation; Physical Layer Diagnostics; Surge Protection - Eaton Crouse-Hinds Series Instruction Manual

4
+
Power A
–
+
Power B
–
Figure 2 .3 - Power distribution to modules
2 .3

Alarms

Each 919x-FP module monitors the output of the four fieldbus segments and indicates
an alarm (by means of a built-in, normally-closed relay) if any of the segments is
shorted, or its output falls below the 'minimum output voltage threshold'. Failure of
either of the two bulk power input supplies is also announced.
The alarm contacts are volt-free and galvanically isolated from other circuitry.
Connections to the alarm relays are made via terminals on the 9188-CA-Px carrier; a
separate alarm module is not required for this function, but see Section 5.8 on page
11 for guidance when power modules are removed from the carrier.
LED indicators show the status of each 919x-FP module and that of the four 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. See Section 5.8 on page 11 for connection details.
2 .4

Isolation

The 919x-FP module provides galvanic isolation 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 power conditioners. There is
also galvanic isolation between the fieldbus segments, thereby preventing multiple
segment failures due to ground faults on more than one segment.
2 .5

Physical layer diagnostics

A separate physical layer diagnostics module - F809F-Plus - may be installed on the
carrier to automatically collect and distribute additional diagnostic information for each
of the eight fieldbus segments. For more in-depth information see the F809F-Plus
product specification and its instruction manual (INM F809F-Plus).
2 .6

Surge protection

Pluggable surge-protection components for each fieldbus trunk are available as an
option reducing the installed cost of providing surge protection on fieldbus networks.
2 .7

Connector options

Redundant 24V DC (nom.) input power is connected to the 9188-CA-Px carrier using
two-part pluggable connectors. System connections are compatible with ALF111
fieldbus communication modules, via AKB336 cables, and field wiring connections
are available with either pluggable screw terminals (9188-CA-PS) or pluggable spring
clamp terminals (9188-CA-PC). The pluggable connections are screw-retained providing
a reliable connection in an industrial environment.
A B C A B C
INM9188 Rev 5