Phoenix PSR-SPP-24DC/ESD Series Safety Relays: Precise Time-Delay Solutions for Industrial Safety
I. Series Overview: Reliable Protection with Adjustable Response
The Phoenix PSR-SPP-24DC/ESD series represents premium safety relays designed for industrial automation, featuring ESD protection and selectable dropout delays for critical safety applications. These compact devices (22.5mm width) provide 5 normally open (NO) + 1 normally closed (NC) contacts, supporting 1/2-channel control with Cat. 4/PL e/SIL 3 safety ratings (for undelayed contacts) Phoenix USA.
The variants in your list differ only in their fixed dropout delay times (T1 to T30S and 300), making them ideal for applications requiring controlled shutdown/restart sequences in machinery, robotics, and industrial plants.
II. Core Specifications: What Makes This Series Stand Out?
Key Parameters:
- Supply Voltage: 24V DC (-15%/+10% = 20.4V-26.4V DC) Phoenix Contact USA
- Contact Configuration: 5NO + 1NC (5X1/1X2):
- 5NO for control/signaling
- 1NC for safety monitoring/feedback Phoenix Contact USA
- Safety Ratings:
- Undelayed contacts: Cat. 4/PL e/SIL 3 (highest industrial safety level)
- Delayed contacts: Cat. 3/PL d/SIL 2 Phoenix Contact USA
- Switching Capacity: 6A max. continuous current, 250V AC/DC max. voltage Phoenix Contact USA
- ESD Protection: Built-in surge suppression diode for protection against electrostatic discharge and voltage spikes Phoenix Contact USA
- Mechanical Life: 10 million cycles Phoenix Contact USA
- Mounting: DIN rail (any position), IP20 protection Phoenix Contact USA
Time Delay Variants in Your List:
| Part Number | Delay Time | Application Focus |
|---|---|---|
| 2981509 | T10S (10 seconds) | Machinery requiring controlled coast-down (e.g., conveyor systems) |
| 2981431 | 300 (300 milliseconds) | Quick-response safety circuits (e.g., light grid protection) |
| 2981350 | T30 (30 seconds) | Large equipment requiring extended shutdown time (e.g., industrial ovens) |
| 2981334 | T20 (20 seconds) | Medium-sized machinery with moderate stopping inertia |
| 2981318 | T15 (15 seconds) | General-purpose delayed safety applications |
| 2981091 | T10 (10 seconds) | Standard delayed shutdown (e.g., pump systems) |
| 2981295 | T6 (6 seconds) | Smaller machinery with shorter stopping time |
| 2981253 | T4 (4 seconds) | Precise timing applications (e.g., robotic cells) |
| 2981237 | T3 (3 seconds) | Fast-acting safety with slight delay |
| 2981198 | T2 (2 seconds) | Very short delay for near-instantaneous yet safe shutdown |
| 2981156 | T1 (1 second) | Minimal delay for critical safety interlocks |
III. Series Nomenclature Decoding: Understand the Part Number
PSR-SPP-24DC/ESD/5X1/1X2/T10S breaks down as:
- PSR: Safety Relay Series
- SPP: Standard protection with push-in connection
- 24DC: 24V DC supply voltage
- ESD: Built-in ESD (surge) protection
- 5X1: 5 normally open contacts (5NO)
- 1X2: 1 normally closed contact (1NC)
- T10S: Fixed dropout delay of 10 seconds Phoenix Contact USA
IV. Applications: Where These Relays Excel
Primary Use Cases:
- Emergency Stop Systems: Safe shutdown of machinery with controlled delay Phoenix Contact USA
- Safety Door Monitoring: Prevents operation when safety barriers are opened Phoenix Contact USA
- Light Grid/Sensor Protection: Delayed response to ensure personnel clearance Phoenix Contact USA
- Conveyor Systems: Controlled coast-down to prevent product damage
- Robotics Cells: Safe power-off with precise timing for mechanical stability
- Industrial Ovens/Heaters: Gradual shutdown to prevent thermal shock
Why Choose This Series Over Alternatives?
- Dual Safety Rating: Meets both EN ISO 13849 (Cat. 4/PL e) and IEC 61508 (SIL 3) standards Phoenix Contact USA
- ESD Protection: Built-in surge suppression extends relay life in harsh industrial environments Phoenix Contact USA
- Fixed Delay Options: Eliminates need for external timers, reducing complexity and cost
- Compact Design: 22.5mm width saves space in crowded control cabinets Phoenix Contact USA
- Push-in Terminals: Quick, tool-free wiring for easy installation and maintenance Phoenix Contact USA
V. Selection Guide: How to Choose the Right Variant
Step 1: Confirm Voltage and Contact Requirements
- Ensure 24V DC power supply compatibility
- Verify 5NO+1NC configuration meets your safety circuit needs
Step 2: Select the Appropriate Delay Time
General Guidelines:
- T1-T6 (1-6 seconds): Use for small equipment with minimal inertia (e.g., desktop machines, small conveyors)
- T10-T20 (10-20 seconds): Ideal for medium-sized machinery (e.g., production lines, packaging equipment)
- T30 (30 seconds): Recommended for large systems requiring extended shutdown (e.g., industrial mixers, large fans)
- 300 (300ms): Best for applications needing quick response with minimal delay (e.g., light curtains, safety fences)
Step 3: Application-Specific Recommendations
| Application | Best Delay Choice | Rationale |
|---|---|---|
| CNC Machine Emergency Stop | T4-T6 | Balances safety with production efficiency |
| Automated Warehouse Conveyors | T10-T15 | Allows product stabilization during shutdown |
| Robotic Assembly Cell | T2-T4 | Prevents abrupt stops that could damage components |
| Pharmaceutical Processing | 300ms | Immediate yet controlled response for sterile environments |
| Heavy Machinery (Presses) | T20-T30 | Ensures complete mechanical stabilization |
VI. Important Considerations
1. Safety Ratings Note
- Undelayed contacts (3NO): Cat. 4/PL e/SIL 3 (highest safety level)
- Delayed contacts (2NO): Cat. 3/PL d/SIL 2 (still high safety but reduced for timed operations) Phoenix Contact USA
2. Wiring & Installation
- Conductor Range: Accepts 0.2-1.5mm² solid or stranded wires Phoenix Contact USA
- Mounting: Standard 35mm DIN rail, can be installed in any position Phoenix Contact USA
- Housing: Yellow (RAL 1018) for easy identification in control panels
3. Environmental Conditions
- Operates reliably from -20°C to +55°C (with derating at higher temperatures) Phoenix Contact USA
- IP20 protection (requires IP54 environment for installation) Phoenix Contact USA
VII. Summary & Next Steps
The Phoenix PSR-SPP-24DC/ESD series offers versatile safety relay solutions with built-in ESD protection and selectable delay times. Your list represents a comprehensive set of delay options (1 second to 30 seconds plus 300ms) to address nearly any industrial safety application requiring controlled timing.
Final Recommendation:
- For emergency stop circuits in general machinery: T4-T10 variants provide optimal balance of safety and practicality
- For light grid/access protection: 300ms variant offers rapid response
- For large equipment with significant inertia: T20-T30 variants ensure safe shutdown
Phoenix PSR-SPP-24DC/ESD Series Safety Relays: Precise Time-Delay Solutions for Industrial Safety
Created on：2025-12-09 11:13
