Rockwell Automation 1797-XXX FLEX Ex System Certification Reference Manual - Manual (Page 161)

Publication 1797-6.5.6 - June 2005
1797-PS1N FLEX Ex Power Supply 33-3
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
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 NEC, ANSI/NFPA 70,
Article 504 or the CEC CSA C22.1, Part 1, Appendix F. For additional
information refer to ANSI/ISA RP12.6.
Wiring methods must be in accordance with the NEC, ANSI/NFPA 70,
Article 501 or the CEC CSA C22.1, Part 1, Section 18.
For mounting of the power supply, conduit runs must have sealing fittings
connected within 6 inches of enclosure.
Ch4
Ch3
Ch2
Ch1
1 2 3 4 5
17
16
15
14
13
12
11
10
11
12
Nonhazardous Location
Hazardous (Classified) Location
1797-PS1N
Class I, Division 1, Groups A, B, C, D
Class II, Division 1, Groups E, F, G
Class III, Division 1
power
supply
Hazardous (Classified) Location
Class I, Division 1, Groups A, B, C, D
Class II, Division 1, Groups E, F, G
Class III Division 1
nonintrinsically safe wiring
intrinsically safe wiring
To any IS device with entity
concept parameters of
(V
max
, I
max
, C
i
, L
i
) appropriate
for connection to associated
apparatus with entity
concept parameters listed in
Table 1: Entity Values for
Field Device Connections.
42101