Ronan X57 - Manual (Page 2)

Intrinsic Safety Barriers are devices
which limit the power (energy) that
can be delivered from a safe area into a
hazardous area. Explosions are therefore
prevented, not just contained, as in expan-
sion proof conduit and heavy cast housings.
Not only is electrical energy (voltage and
current) held within safe limits, but also
total energy, eliminating the possibility of
an explosion due to excessive heat. The use
of barriers and a total intrinsically safe
design philosophy offers considerable
advantages from both cost and safety
standpoints.
The following features indicate the clear benefits of
choosing an intrinsically safe design instead of an
explosion-proof design, and reflect the unique features of
the Series X57 family of barriers.
◗ All system components are immediately accessible — no time
consuming opening of explosion proof housings.
◗ Personnel safety is assured because of low voltage operation.
◗ Standard wiring techniques in open cable trays or light
gauge conduit save on material and labor cost during
initial installation.
◗ Calibration and maintenance can be performed with the
system in operation.
◗ Special skill levels are not needed to open heavy housings,
to test for gas, or to shut down the process in order to
service or operate the instrumentation.
◗ Barrier replacement is accomplished by simple exchange of
plug-in modules. There is no need to disconnect wiring or
to remove ground bars.
◗ Barriers are manufactured and stocked in the U.S.A. in
Woodland Hills, California. (Los Angeles area)
◗ Multiple channels in one barrier minimize the total number
of barrier modules needed and space required.
The Ronan I.S. Barriers are plug-in modules containing
one to four channels. Up to twenty barrier modules can be
installed in a 20 position surface mounted chassis. Single
barrier surface or DIN rail chassis are also available. Each
module has eight screw terminals. The terminals are
arranged in the chassis so that four are located in the safe
area and four are located in a protected compartment for
the wiring to the hazardous area. The safe area terminals
are numbered 1 through 4 and the protected terminals
are numbered 5 through 8. These compression type screw
terminals accept up to 12 AWG wire. The safe area
terminals are connected to equipment in a location where
the sources of potential with respect to each other or to
ground do not exceed 250 Vdc or RMS. The I.S. grounding
connection for the barriers is provided by an integral,
fixed, #8 stud with self-locking nuts. Optional ground bus
bars and multi-pin cable connectors are also available.
X57
I n t r i n s i c S a f e t y B a r r i e r s I n t r i n s i c S a f e t y B a r r i e r s
2