Rockwell Automation 1797-ACNR15 ControlNet Ex Redundant Media Adapter - Manual (Page 24)

24 ControlNet Ex Redundant Media Adapter
Publication 1797-5.14 - March 2010
FM ControlNet Ex System Diagram Notes
The entity concept allows interconnection of intrinsically safe apparatus
with associated apparatus not specifically examined in combination as a
system when the approved values of V
oc
and I
sc
or V
t
and I
t
of the associated
apparatus are less than or equal to V
max
and I
max
of the intrinsically safe
apparatus and the approved values of C
a
and L
a
of the associated apparatus
are greater than C
i
+ C
cable
and L
i
+ L
cable
respectively for the intrinsically safe
apparatus.
Wiring methods must be in accordance with the National Electric Code,
ANSI/NFPA 70, Article 504 and 505. For additional information refer to
ANSI/ISA RP12.6.
WARNING: Substitution of components may impair intrinsic safety.
If fiber optic cable is provided with a metal shield, it must be connected
to a dedicated intrinsic safety ground in the nonhazardous location and tied
back in the hazardous location or be connected to a ground in the hazardous
location and tied back in the nonhazardous location.
The glass fiber must have a minimum diameter of 6 μm.
The ControlNet Ex tap must be connected directly to the module (no
additional cable may be connected).
Must be FM approved.
Total coax trunk cable length is limited to 1000 m (3280 ft) with up to 2
ControlNet Ex taps connected and to 250 m (820 ft) with the maximum
allowed ControlNet Ex taps of 48. For ControlNet Ex taps between 2 and 48
use: 1000 m (3280 ft) - 16.3 m (53.4 ft) x (number of taps - 2) to find the
maximum allowed cable length.
Power supplies are suitable for mounting in Class I, Division 1, Groups
B-D or Class I, Zone 1, Group IIC.
The maximum number of 1797-ACNR15 modules that can be connected
to one system is 47.
The maximum number of 1797-RPA modules that can be connected to
one system is 47.
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