Rockwell Automation 1797-XXX FLEX Ex System Certification Reference Manual - Manual (Page 174)

Publication 1797-6.5.6 - June 2005
38-2 General FM Certification Information
I/O module capacitance value is cumulative. C
i (total)
= C
i (I/O module 1)
+
C
i (I/O module 2)
+ ... C
i (I/O module 8)
+ C
cable
(C
cable
= 100pf). C
i (total)
must be less than 30µF
(when the 1797-ACNR15 is used) or 39.67µF (when the 1797-BIC is used).
The limitation of 8 I/O modules per adapter is a functional limitation. Refer to
table 3 of the appropriate module for C
i
values. Note: Any combination of up
to eight FLEX Ex I/O modules meets this requirement. (This includes
1794-CE3, 1797-CE3, 1794-CE1, and 1797-CE1 cables.)
In any of the above diagrams, terminal bases without modules may be
connected.
This general FM certification information must be used in conjunction
with the appropriate module certification information.
Installation in Division 1/
Zone 1 Modules, adapters, and terminal base units must not be exposed to the
environment. Provide a suitable enclosure.
1 2 3 4
5 6 7 8 42488
connecting cable
1794-CE1 or -CE3
ATTENTION
Modules, adapters, and terminal base units cannot be used
in an intrinsically safe environment after they have been
exposed to non-intrinsically safe signals.