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Power Supply

The SEL-9331 Power Supply is a high-output +12 Vdc, 200-watt fanless power supply designed for SEL’s line of computing platforms and is powerful enough to meet the needs of many other applications. Capable of producing 11 A of continuous current from –40° to +85°C, and 17 A of maximum current, the SEL-9331 can provide ample power in environments where many supplies cannot. High Voltage (120/240 Vac or 125/250 Vdc) and Low Voltage (48 Vdc) models enable use with a wide range of power sources.

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SEL Computing Platform Power Supply—The SEL-9331 is a switched-mode +12 Vdc power supply designed to supply power to SEL’s line of industrial computing platforms. Multiple form factors are available, including internal modules for the SEL-3355 computing platform and SEL-3555 Real-Time Automation Controller (RTAC) and external modules for the SEL-3360S computing platform. The SEL-9331 also serves as the internal power supply in the SEL-3360E computing platform.

Redundant Power Source—The SEL-9331 is flexible enough to provide power for any equipment that require a reliable 12 Vdc power source in harsh environments. Multiple SEL-9331 Power Supplies can be connected in parallel, without any external supporting circuitry, for simple integration of multiple power sources.

Industrial Equipment Power Supply—Power industrial equipment in harsh environments. With no vent holes or fans, the SEL-9331 is resistant to contamination from dust and debris. The wide operating temperature range of –40° to +85°C (–40° to +185°F) is well-suited for non-climate-controlled conditions, such as outdoor enclosures and plant floors. Optional conformally coated circuit boards provide an extra level of protection in damp, corrosive, or otherwise polluted environments.


Backed by SEL’s ten-year warranty, the SEL-9331 is designed and tested to operate in environments with extreme temperatures, shock, and vibration. With no vent holes, fans, or moving parts, the SEL-9331 provides reliable zero-maintenance operation.

Multiple Mounting Options
The SEL-9331 can be easily mounted to a panel or DIN rail.

Two SEL-9331 outputs can be connected in parallel to provide a backup power supply in case one source fails.

Power Factor Correction
Minimizes reactive power and induced harmonics for improved efficiency of ac power systems.

Reverse-Polarity Protection
Protects against damage in the event that input wiring is accidentally reversed.

Autorecovery From Undervoltage
Undervoltage lockout prevents misoperation during brownout conditions.

Short-Circuit Protection
Prevents damage caused by excessive load.

Reverse-Current Protection
Prevents reverse-current flow caused by an overvoltage condition on the output.

Power Good Indicator
The standalone power supply features a “power good” LED to indicate when the SEL-9331 is operating normally. When installed in an SEL-3355, the power supply can be monitored by the SEL System Monitor and Microsoft Windows performance counters.

Conformal Coating (optional)
Conformal coating of the circuit board provides an extra level of protection in corrosive environments. Learn more about conformal coating.

The Firmware IDs for older versions of the firmware can typically be found in Appendix A of the instruction manual.

Instruction Manuals