Rockwell Automation 1797-PS2E2 FLEX Ex Power Supply - Manual (Page 4)

4 FLEX Ex Power Supply
Publication 1797-5.8 - June 2010
The 1797-PS2E2 is a 24V dc in/quad-Ex dc out power supply in an
flame-proof enclosure with increased safety input and output terminations.
The 24V dc gland is an M20 x 1,5 and can accept a cable from 6…12 mm
(0.267…0.472 in.) in diameter. The Ex outputs are M16 x 1,5 and can accept a
cable from 4…8 mm (0.157…0.315 in.) in diameter.
Features include the following:
 24V dc supply source
 Four channels, 8.5 W output each channel
 Dual power feeds for source input redundancy
 Outputs are IS galvanically isolated from the source
 All channels are independently IS limited
Understand System Planning
Part of system planning is determining what modules are needed for the
application, how many power supplies are needed, how to best partition the
system, and where to locate the system cabinets.
A key task in the development cycle is determining the number of power
supply outputs (thus power supplies) you will need. In the following example,
you will need 11 power outputs if you are using the fiber hub, which requires
8.5 W.
Each power supply has four independent IS-power outputs capable of 8.5 W
each. In the above example, we required 11 IS-power outputs so 3 power
supplies were sufficient.
Modules Requires Modules Requires
Fiber hub 8.5 W Two thermocouple inputs 1.6 W each
Two ControlNet a dapters 8.5 W each Two digital outputs 7.5 W each
Two analog inputs 7.5 W each Three NAMUR digital inputs 2.8 W each
Two analog outputs 6.3 W each Two counter inputs 4.25 W each