Phoenix S-PT Series: Explosion-Proof Surge Protectors for Industrial Sensors
Product Overview
Phoenix S-PT Series are specialized explosion-proof surge protection devices designed to safeguard industrial sensor signals from voltage spikes and transient surges in hazardous environments. These compact modules provide reliable protection for analog/digital signals while maintaining signal integrity and system functionality. With IP67 protection and various mounting options, they're ideal for field installations where sensor circuits need protection against electrical overstress.
Model & Core Parameter Table
| Model No. | Product Type | Voltage | Channels | Mounting Thread | Protection Class | Main Application |
|---|---|---|---|---|---|---|
| 2800037 | S-PT-4-EX-24DC-1/2" | 24V DC | 4 channels | 1/2" NPT | Ex tD A21 IP67 | 4-wire sensor protection (e.g., 3-wire RTD) |
| 2800036 | S-PT-4-EX-24DC | 24V DC | 4 channels | PCB mount | Ex tD A21 IP6x | Panel-mounted 4-channel protection |
| 2800039 | S-PT-2XEX-48DC-1/2" | 48V DC | 2x2 channels | 1/2" NPT | Ex tD A21 IP67 | Dual 2-wire sensor protection |
| 2800038 | S-PT-2XEX-48DC | 48V DC | 2x2 channels | PCB mount | Ex tD A21 IP6x | Dual 2-wire protection in control cabinets |
| 2800041 | S-PT-2XEX-24DC-1/2" | 24V DC | 2x2 channels | 1/2" NPT | Ex tD A21 IP67 | Dual 24V sensor protection in hazardous areas |
| 2800040 | S-PT-2XEX-24DC | 24V DC | 2x2 channels | PCB mount | Ex tD A21 IP6x | Dual-channel protection in control panels |
| 2882598 | S-PT-1X2-24DC-3/4" | 24V DC | 1x2 channels | 3/4" NPT | IP67 | Single-channel dual-line protection |
| 2882569 | S-PT-1X2-24DC-1/2" | 24V DC | 1x2 channels | 1/2" NPT | IP67 | Single-channel dual-line protection |
| 2880668 | S-PT-1X2-24DC | 24V DC | 1x2 channels | PCB mount | IP6x | Single-channel dual-line protection in panels |
Model Code Interpretation
S-PT: Signal Protection Transient (surge protection device)
- 4: 4-channel protection
- 2XEX: 2x2 channels (dual circuit protection)
- 1X2: 1x2 channels (single circuit with two lines)
- EX: Explosion-proof design (Ex tD A21)
- 24DC/48DC: Rated DC voltage (24V/48V)
- 1/2"/3/4": NPT mounting thread size (for direct sensor head installation)
Core Specifications
1. General Parameters
- Protection Class: Ex tD A21 IP67 (dustproof, waterproof, explosion-proof in hazardous areas)
- Operating Temperature: -40°C to +80°C (suitable for extreme industrial environments)
- Connection Type: Screw terminals for easy wiring
- Mounting Options:
- Threaded models: Direct installation on sensor heads via NPT thread
- PCB models: Panel/cabinet mounting
2. Electrical Performance
- Nominal Discharge Current (8/20μs): 10kA (line-earth), 0.17kA (line-line)
- Maximum Continuous Voltage:
- 24V models: 30V DC/28V AC
- 48V models: 53V DC/37V AC
- Voltage Limitation: ≤130V (line-line surge), ≤1.1kV (line-earth surge)
- Leakage Current: ≤5μA (ensures minimal impact on sensitive signals)
- Response Time: <1ns (immediate protection against transients)
Application Scenarios
Key Applications
| Scenario | Recommended Model | Why? |
|---|---|---|
| 4-wire Temperature Sensors (e.g., RTDs) | 2800037 (S-PT-4-EX-24DC-1/2") | 4-channel protection covers all RTD wires, threaded mount for direct sensor integration |
| Dual 2-wire Transmitters | 2800039 (S-PT-2XEX-48DC-1/2") | 2x2 channels protect two separate 2-wire sensors, 48V compatibility for industrial transmitters |
| General Industrial Sensors (24V) | 2882569 (S-PT-1X2-24DC-1/2") | Single-channel dual-line protection for standard 24V sensors, threaded mount for field installation |
| Control Cabinet Protection | 2800036/2800040/2880668 | PCB mounting for centralized protection of multiple sensors in control panels |
| Hazardous Areas (ATEX zones) | All EX models | Explosion-proof design prevents ignition in potentially explosive atmospheres |
Key Advantages
-
Complete Signal Protection:
- Protects against both line-line and line-earth surges
- Prevents damage to sensors and control equipment from voltage transients
-
Explosion-Proof Design:
- Ex tD A21 certification allows use in hazardous industrial environments
- IP67 protection ensures reliable operation even in wet/dusty conditions
-
Versatile Mounting:
- Threaded models eliminate need for additional mounting brackets
- Direct installation reduces cabling and installation time
-
Minimal Signal Disturbance:
- Low leakage current and fast response time ensure signal integrity
- HART-compatible (for intelligent transmitters)
Important Selection Notes
-
Voltage Compatibility:
- Always match device voltage with S-PT rating (24V devices → 24V model; 48V devices → 48V model)
-
Channel Selection:
- 4-channel: For 4-wire sensors (e.g., RTDs)
- 2x2-channel: For two separate 2-wire sensors
- 1x2-channel: For single 2-wire sensor with protection on both lines
-
Mounting Location:
- Use threaded models (with 1/2" or 3/4" NPT) for field-installed sensors
- Use PCB models for centralized protection in control cabinets
Summary
Phoenix S-PT Series provides essential explosion-proof surge protection for industrial sensors in hazardous environments. With models covering 24V/48V systems and various channel configurations, they ensure reliable signal transmission while protecting against damaging voltage surges. Choose based on your sensor type (2-wire/4-wire), voltage requirements, and installation location (field/cabinet).
Phoenix S-PT Series: Explosion-Proof Surge Protectors for Industrial Sensors
