Description
1. Product Overview
Allen‑Bradley 1797‑PS1E is an intrinsically safe explosion-proof dedicated power supply module of the FLEX Ex series manufactured by Rockwell Automation. Designed for hazardous locations with flammable and explosive substances in Zone 0, Zone 1 and Zone 2, it serves as the core power supply unit for FLEX Ex explosion-proof distributed I/O systems. As an explosion-proof and intrinsically safe power unit, it converts conventional AC mains power into multiple independent current-limited intrinsically safe DC power supplies. It delivers isolated safe power for field explosion-proof I/O modules, intrinsically safe sensors and field explosion-proof substations, eliminating safety risks caused by electric sparks and overheating in flammable and explosive environments.
The 1797‑PS1E supports wide-range industrial AC input from 85 to 253 V AC and is equipped with four fully independent intrinsically safe output channels. Each channel features independent current limiting, voltage limiting and power limiting, along with electrical isolation and fault latching protection. Compliant with dual standards of Ex d flameproof and intrinsically safe protection, the module holds ATEX and IECEx international explosion-proof certifications and is suitable for hazardous automation scenarios such as chemical, petrochemical, oil & gas and pharmaceutical industries. Featuring a rugged structure, high protection grade and strong anti-interference performance, it supports 7×24-hour continuous stable operation. It is the standard core power module for new assembly of industrial explosion-proof distributed I/O systems, maintenance replacement of legacy explosion-proof equipment, and compliance retrofitting of explosion-proof systems.
2. Functional Features
Multiple independent intrinsically safe outputs for zoned safe power supply The module integrates four fully independent intrinsically safe output channels with mutual isolation. Each channel can individually power intrinsically safe explosion-proof I/O modules, explosion-proof sensors and field detection instruments. With independent current and voltage limiting for each channel, short circuit, overload or fault on one channel will not affect other channels or the whole power supply system. It guarantees stable zoned power supply for multiple devices in explosion-proof substations and greatly improves operational safety and fault tolerance of explosion-proof systems.
Strict intrinsically safe parameter restriction to eliminate explosion hazards The output terminal strictly limits voltage, current and power. The intrinsically safe output voltage ≤9.5 VDC, single-channel output current ≤1 A, single-channel maximum output power 8.5 W, and total module output power 34 W. Precise hardware clamping of electrical parameters ensures no high-energy release, electric spark or abnormal high temperature under fault conditions. It fully meets intrinsically safe requirements for gas and dust flammable & explosive environments and eradicates ignition risks at the electrical level.
Full electrical isolation between input and output, anti-interference and anti-cross-talk Complete electrical isolation is implemented between the mains input and intrinsically safe outputs, as well as among the four output channels. It blocks industrial grid surges, noise interference and common-mode voltage intrusion into field intrinsically safe loops. It protects downstream precision explosion-proof instruments and I/O modules from grid fluctuation damage, and prevents field faults from striking back to core cabinet equipment, suitable for complex explosion-proof sites with heavy electromagnetic interference.
Wide-range AC input with excellent grid adaptability It supports ultra-wide input voltage of 85–253 V AC, covering global industrial mains standards. It tolerates grid deviation, transient surges and voltage fluctuations at industrial sites. Stable intrinsically safe power can be supplied without extra voltage regulators. It fits hazardous sites with unstable plant power supply and large voltage drop over long-distance transmission, delivering better power stability and compatibility than ordinary explosion-proof power supplies.
Multi-layer intelligent protection with latching fault safety control Built-in four comprehensive protection functions including overvoltage, overcurrent, short circuit and overtemperature protection. When any channel suffers short circuit, overload or abnormal temperature rise, the module immediately triggers latching protection, cuts off power of the faulty loop instantly and locks the fault state to prevent fault escalation. Operators can manually reset the module after troubleshooting. Clear fault positioning enables safe controllable operation for unattended explosion-proof sites.
- High-grade explosion-proof protection for long service life under severe conditions The module adopts Ex d flameproof housing and has passed ATEX and IECEx explosion-proof certifications, applicable to Zone 1 and Zone 22 hazardous explosion-proof areas. IP65 protection rating provides dust resistance, splash water resistance, moisture resistance, corrosion resistance and vibration resistance. It can withstand high temperature, high humidity, dust and corrosive gas in petrochemical and oil & gas sites for long-term operation with outstanding weather resistance and service life.
3. Technical Specifications
3.1 Basic Specifications
Product Model: 1797-PS1E Manufacturer: Allen‑Bradley (Rockwell Automation) Product Series: 1797 FLEX Ex Explosion-Proof Distributed I/O System Product Type: Flameproof and intrinsically safe explosion-proof power supply module Core Function: Special safety power supply unit for explosion-proof I/O substations, intrinsically safe instruments and explosion-proof sensors Key Characteristics: Four independent intrinsically safe outputs, full electrical isolation, wide-range AC input, multi fault protection, IP65 high protection, international explosion-proof certification, 7×24-hour stable operation.
3.2 Input Electrical Parameters
Input Voltage Range: 85～253 V AC Input Frequency: 47～63 Hz Applicable Mains: Global universal industrial AC power Input Feature: Built-in surge suppression and filter circuit, resistant to grid fluctuation and transient impact; no external voltage regulator required.
3.3 Intrinsically Safe Output Parameters
Output Channels: 4 independent intrinsically safe isolated channels Single-channel Maximum Output Power: 8.5 W Total Module Output Power: 34 W Intrinsically Safe Output Voltage (Uo): ≤9.5 V DC (Hardware voltage limiting) Intrinsically Safe Output Current (Io): ≤1 A (Hardware current limiting) Output Isolation: Full electrical isolation between channels and between input and output Protection Mechanism: Independent short-circuit, overload, overvoltage and overtemperature latching protection per channel.
3.4 Mechanical & Wiring Parameters
Wiring Ports: M16×1.5 standard explosion-proof cable glands Applicable Cable Diameter: 4～8 mm industrial explosion-proof cables Mounting Method: Wall-mounted explosion-proof installation, compatible with explosion-proof cabinets and field enclosures Housing Material: High-strength explosion-proof flame-retardant alloy housing, impact-resistant, corrosion-resistant, flame-retardant and insulated.
3.5 Protection Parameters
Applicable Zones: Zone 1, Zone 22 flammable & explosive areas Protection Class: IP65 Flame Retardant Grade: Top industrial flame retardant standard Environmental Resistance: Vibration & shock resistance, resistance to sharp temperature & humidity change, mild corrosion, dust and oil accumulation.
3.6 Environmental Operating Parameters
Operating Temperature: -20℃～+70℃ Storage Temperature: -25℃～+80℃ Relative Humidity: 5%～95% non-condensing Operation Mode: 7×24-hour non-stop continuous operation all year round Applicable Conditions: Petrochemical, chemical, oil & gas, fine chemical, pharmaceutical, dust explosion and other high-risk industrial scenarios.
4. Hardware Configuration & Structural Advantages
Four-channel independent intrinsically safe architecture with high power supply fault tolerance Different from ordinary centralized power supplies, the four output channels are fully isolated. Fault latching and isolation on one channel will not interrupt power of the other three channels. It can supply power separately for four groups of explosion-proof I/O equipment and sensor loops with zoning control without mutual interference. It greatly improves overall fault tolerance of explosion-proof systems and avoids shutdown of the whole substation caused by single-point failure.
Hardware intrinsically safe parameter clamping to achieve intrinsic safety Hardware circuits precisely clamp voltage, current and power. Under both normal operation and fault conditions such as short circuit and overload, the energy at output terminals is always lower than the ignition energy of flammable and explosive media. It fundamentally eliminates risks of electric spark and high-temperature ignition, fully meeting intrinsic safety requirements for high-risk explosion-proof areas, with higher safety and compliance than conventional industrial power supplies.
Full isolation anti-interference design for strong system stability Full electrical isolation between input and output, as well as between channels, blocks grid harmonics, surges and electromagnetic crosstalk. It protects downstream precision explosion-proof instruments and I/O modules and prevents field faults from striking back to cabinet equipment, suitable for heavy electromagnetic interference workshops densely equipped with frequency converters and high-frequency devices in chemical plants.
Wide-voltage adaptive input adapting to complicated power supply environment The 85–253 V AC ultra-wide input range perfectly adapts to sites with unstable plant power, large voltage drop over long-distance transmission and instantaneous grid fluctuation. Standard intrinsically safe power can be stably output without additional voltage regulation and filtering devices, reducing supporting system cost and construction complexity.
Flameproof IP65 high-protection housing for excellent field adaptability High-strength flameproof alloy housing with IP65 dust and splash water protection can be deployed directly in outdoor or dusty, humid, mildly corrosive explosion-proof sites without extra protective enclosures. The module resists vibration, shock and ageing, with no housing deformation or seal failure under long-term operation, suitable for all-weather continuous production.
- Modular integrated design for convenient and efficient maintenance Integrated one-piece structure without complicated external accessories, simple installation and standardized wiring. Single module can be inspected, reset or replaced independently upon failure without modifying the whole explosion-proof power loop. It greatly reduces maintenance difficulty and downtime for explosion-proof systems, matching low-frequency maintenance requirements at high-risk field sites.
5. Application Scenarios
Petrochemical & chemical explosion-proof automation systems: Deployed in high-risk explosion-proof workshops of refining, fine chemical and coal chemical plants. It provides safe intrinsically safe power for FLEX Ex explosion-proof I/O substations, intrinsically safe temperature/pressure/level sensors and explosion-proof discrete instruments to guarantee stable operation of explosion-proof processes.
Oil & gas production and storage & transportation explosion-proof applications: Applied to Zone1/Zone22 hazardous areas of oilfields, gas fields, long-distance oil & gas pipelines and storage depots. It supplies intrinsically safe power for field explosion-proof detection equipment and remote I/O substations to mitigate electrical safety hazards under field high-risk conditions.
- Pharmaceutical and light-industry dust explosion-proof systems: Used in pharmaceutical chemical, food processing, powder manufacturing and other scenarios with flammable dust or vapour. Paired with explosion-proof automation equipment to satisfy safety production and explosion-proof compliance acceptance criteria.
