Phoenix STEP3-PS/1AC/24DC/3.75/PT/CO Power Supply
The Phoenix STEP3-PS/1AC/24DC/3.75/PT/CO Power Supply (Item No: 1321105 ) offers a 110 V DC ... 250 V DC -20 % ... +10 % input voltage range, > 92.5 % (120 V AC) efficiency, 24 V DC nominal output voltage, 3.75 A nominal output current. Manufactured by Phoenix under the Phoenix Power Supply category, this model belongs to the Phoenix STEP Series.
| Brand | Phoenix Contact |
| Product Type | Power Supply |
| Model Number | STEP3-PS/1AC/24DC/3.75/PT/CO |
Phoenix STEP3-PS/1AC/24DC/3.75/PT/CO Power Supply – Technical Specifications
| Specification | Value |
|---|---|
| Input voltage range | 110 V DC ... 250 V DC -20 % ... +10 % |
| Inrush current | typ. 30 A (25 °C) |
| Efficiency | > 92.5 % (120 V AC) |
| Nominal output voltage | 24 V DC |
| Nominal output current (IN) | 3.75 A |
| Residual ripple | typ. 100 mVPP |
| Short-circuit-proof | yes |
| Power loss nominal load max. | < 5.7 W (230 V AC) |
| Insulation voltage input/output | 4 kV AC (type test) |
| Mounting type | DIN rail or direct mounting |
| Degree of protection | IP20 |
| Ambient temperature (operation) | -10 °C ... 70 °C (Derating > 50°C: 2 %/K) |
| Frequency range (fN) | 50 Hz ... 60 Hz ±10 % |
The Phoenix STEP3-PS/1AC/24DC/3.75/PT/CO (Item No: 1321105) delivers consistent 24 V DC output at 3.75 A with typical ripple levels of just 100 mVPP, making it ideal for precision electronics and sensitive automation systems. This short-circuit-proof unit operates across a broad input range of 110 V DC to 250 V DC with a tolerance of -20% to +10%, accommodating fluctuating supply conditions commonly found in industrial plants. With an industry-leading efficiency of over 92.5% at 120 V AC, it minimizes power loss and heat, keeping power dissipation under 5.7 W even at full load.
The device supports both DIN rail and direct mounting and operates reliably from -10 °C to +70 °C, with a linear derating above 50 °C. Electrical safety is ensured by a 4 kV AC insulation voltage between input and output, and it meets EN 61000-6-1 and EN 61000-6-3 EMC requirements for industrial immunity and low emissions. The IP20 protection class suits most control cabinet installations, while the typical inrush current of 30 A at 25 °C ensures stable startup without stressing upstream components.
The STEP3-PS/1AC/24DC/3.75/PT/CO is widely chosen for powering distributed control systems, PLCs, and relay modules in manufacturing plants, packaging lines, and building automation systems. It serves maintenance engineers seeking compact, efficient, and maintenance-free DC supplies in harsh environments where uptime is critical. This unit simplifies the design of modern control cabinets, delivering stable voltage under varying load conditions. Whether you're working on a new build or retrofit, this Phoenix Contact power supply ensures reliable performance with minimal thermal impact. Phoenix Contact Official Product Page.
