The SEL-2488 (PN: 24880RAA2281AX2X1) is a high-precision, GNSS-based (Global Navigation Satellite System) network clock manufactured by Schweitzer Engineering Laboratories (SEL). Designed for critical infrastructure, it provides ultra-accurate time synchronization across industrial and utility networks. By converting satellite timing signals into various standard time-code formats, it ensures that all devices in a system, such as protection relays, RTUs, and recording equipment, share a common, nanosecond-accurate time reference.
Product Specifications
| Feature | Details |
| Model Number | SEL-2488 |
| Part Number | 24880RAA2281AX2X1 |
| Time Source | Multi-constellation GNSS (GPS, GLONASS, Galileo, BeiDou) |
| Timing Accuracy | < 100 ns (relative to UTC) |
| Outputs | IRIG-B, IEEE 1588 (PTP), NTP, Pulse-per-second (PPS) |
| Mounting | 1U Rack Mount |
| Weight | Approximately 2.0 kg – 2.5 kg |
| Country of Origin | USA |
Application Fields
The SEL-2488 is indispensable in environments where timestamping sequence-of-events (SOE) data is mission-critical:
- Substation Automation: Synchronizing Intelligent Electronic Devices (IEDs) to ensure accurate post-fault analysis.
- Synchrophasor Systems: Providing the reference time necessary for Wide-Area Monitoring Systems (WAMS).
- Network Synchronization: Serving as a Grandmaster clock for IEEE 1588 PTP networks in industrial plants.
- Telecommunications: Providing high-precision timing for network infrastructure.
Product Usage Instructions
- Antenna Installation: Mount the GNSS antenna with a clear 360-degree view of the sky. Use low-loss coaxial cable and ensure proper lightning surge protection.
- Mounting: Install the 1U unit in a standard equipment rack. Ensure adequate ventilation.
- Connectivity: Connect the GNSS antenna to the BNC input. Connect the network outputs (PTP/NTP) to your network switches, and wire the physical time-code outputs (IRIG-B/PPS) directly to the timing inputs of your protection relays or recorders.
- Configuration: Access the device via the web interface or terminal console. Configure the output formats (e.g., Modulated vs. Unmodulated IRIG-B) to match your legacy equipment requirements.
- Status Monitoring: Use the front-panel LEDs or the web dashboard to confirm “Satellite Lock” and overall timing health.
Frequently Asked Questions
Q: Why is “Multi-constellation” support important?
A: By tracking multiple satellite systems (GPS, GLONASS, etc.), the SEL-2488 maintains higher availability and accuracy, even in environments with partial sky obstructions or interference.
Q: Can this clock act as an IEEE 1588 PTP Grandmaster?
A: Yes, it is designed to serve as a high-accuracy PTP Grandmaster clock, providing sub-microsecond synchronization to PTP-enabled devices over an Ethernet network.
Q: What happens if the satellite signal is lost?
A: The SEL-2488 includes an internal “holdover” oscillator. If the GNSS signal is lost, the clock maintains timing accuracy using its high-stability internal crystal (or optional Rubidium oscillator) until the signal is recovered.
Q: How do I decode the part number 24880RAA2281AX2X1?
A: This string defines the specific hardware options, such as the number of Ethernet ports, physical output types (copper vs. fiber), and power supply input range. You should refer to the SEL-2488 ordering guide to match these codes to your specific rack requirements.
