1797-PS2E2 FLEX Ex Power Supply

The 1797-PS2E2 module is a FLEX EX I/O series intrinsically safe IECEX 24 Volts DC rated power

supply module designed and manufactured by Allen-Bradley. The 1797-PS2E2 PSU (Power Supply

Unit) is one of the most important components of an intrinsically safe system. Its purpose is to isolate

the incoming power circuit from the hazard zone of the involved electrical control circuits and to disable

the transition of the electrical circuit problems from the input side to the output side. The other task for

the 1797-PS2E2 module is to set a limit for the accessible energy and adjust it to the defined safe levels.

All 4 output channels can be independently IS limited. The 1797-PS2E2 safe IECEX PSU module

delivers 8.5 Watts to each of its 4 output channels. The voltage delivered from this special device for

use in explosive atmospheres is rated at 24 Volts DC and this is the only power source needed for the

components attached to the FLEX Ex system in a hazardous area. The input connectors for 24 Volts

DC voltage are located at terminals 1, 2, 4, and 5. There are 4 terminals to cover 2 power inputs

for source input redundancy. The acceptable input voltage range is from 18 to 32 Volts DC.

1797-PS2E2

The Allen-Bradley 1797-PS2E2 4-Ex outputs DC power supply module is delivered in an IP 65/NEMA 7B

class flame-proof housing that has improved the safety terminations for the inputs and outputs. The input

DC power supply gland is an M20x1 5 that can accept cables with 6 to 12-millimeter diameters. The power

output glands (there are 4 of them) are M16x1 5 that can accept 4 to 8-millimeter wide cables. Through

these cables, power is transferred to the actuators, valves, sensors, or transmitters. The 1797-PS2E2

module supports removal and insertion under power, which enables the making of cable

connections in the hazardous area while the system is operating.