Allen-Bradley 1797-PS1N FLEX Ex Intrinsically Safe Power Supply

Product Overview

The 1797-PS1N functions as a high-performance, Intrinsically Safe (IS) Power Supply specifically engineered for the FLEX Ex I/O platform. This module provides critical power distribution to I/O components situated in hazardous environments. By converting high-voltage AC input into regulated IS-limited power, it ensures safe operation without risking ignition in volatile atmospheres. We offer this unit as 100% Brand New original stock, providing a vital replacement solution for systems requiring the exact specifications of this discontinued series.

Technical Specifications

The 1797-PS1N incorporates robust electrical parameters to maintain system integrity in demanding zones:

Engineering Advantages

• Quad-Channel Independence: This module features four independent output channels. Each channel carries its own Intrinsic Safety limitation, ensuring that a fault on one branch does not compromise the safety or operation of the remaining three.

• Superior Galvanic Isolation: The design provides full galvanic isolation between the AC source and the IS-limited outputs. This physical separation eliminates ground loops and prevents dangerous surges from reaching the hazardous area.

• Wide Universal AC Input: The circuitry accepts a broad input range from 85V to 250V AC. This versatility allows global deployment across various power grids without the need for additional step-down transformers.

• Hazardous Area Compatibility: Specifically designed for FLEX Ex systems, this power supply enables the placement of I/O modules directly in Zone 1 or Zone 2 (Class I, Div 1) areas, significantly reducing wiring costs and cabinet space requirements.

• Effective Thermal Management: Despite its compact form factor, the unit manages a thermal dissipation of 71.67 BTU/hr, ensuring stable voltage regulation even in enclosed industrial control racks.

Installation Guidelines

1. Source Connection: Connect the primary AC power (85-250V) to the designated input terminals. Ensure all wiring adheres to local Intrinsic Safety standards.

2. Mounting: Secure the 1797-PS1N to the FLEX Ex backplane. The module's design allows for rapid "hot-swapping" under specific safe-state conditions, though users must verify local hazardous area protocols.

3. Channel Distribution: Distribute the 8.5W output across the four channels to power FLEX Ex I/O modules. Do not exceed the individual IS limits specified for the connected sensors or actuators.

FAQs

Q: Can the 1797-PS1N be used with standard FLEX I/O modules?

A: No. The 1797-PS1N specifically serves the FLEX Ex (Intrinsically Safe) line. Standard FLEX I/O (1794 series) uses different power requirements and does not support the Intrinsic Safety limitations provided by this module.

Q: How does the galvanic isolation protect the system?

A: It creates an electrical barrier that prevents high-voltage AC from ever reaching the hazardous field side. If a catastrophic failure occurs on the input side, the isolation ensures that no sparks or excess heat reach the explosive atmosphere.

Q: Is this product still available from the manufacturer?

A: Rockwell Automation discontinued the 1797-PS1N in late 2017. However, we provide 100% Brand New original units from our specialized inventory to help maintain legacy systems and avoid costly full-scale hardware migrations.

Q: What is the primary cause of thermal dissipation in this unit?

A: The 21W power dissipation represents the energy lost during the high-to-low voltage conversion and the maintenance of IS current limits. Ensure your enclosure provides adequate ventilation to handle the 71.67 BTU/hr heat output.