PLCs, Power Supplies & Others

This module provides regulated DC power for PLC racks and field devices. It delivers three isolated output voltages from a single AC or DC input source. Engineers use this unit to power processors, I/O modules, and communication adapters simultaneously. The design emphasizes high efficiency and reliable start-up under full load conditions. Its compact dimensions suit standard 19-inch rack installations in industrial cabinets.

Input Specifications and Power Factor

The NP1S-91/81 accepts a universal AC input from 85 VAC to 264 VAC at 47-63 Hz. It also operates from a DC input range of 110 VDC to 370 VDC for flexible installation. The module incorporates active power factor correction for improved efficiency. Power factor exceeds 0.95 under typical load conditions. This feature reduces harmonic distortion and improves overall system power quality.

Output Channels and Rating

This unit provides three independent DC output channels with different voltage levels. The first channel delivers 5 VDC at 20 A for logic and processor modules. The second channel supplies 24 VDC at 3 A for I/O and relay loads. The third channel offers 12 VDC at 2 A for communication and auxiliary devices. Total output power reaches 200 W across all channels combined.

Physical Dimensions and Rack Mounting

The NP1S-91/81 measures 12.7 cm in width, 25.4 cm in height, and 20.3 cm in depth. It weighs approximately 2.5 kg, which reflects the substantial transformer and heatsink assembly. A steel housing with ventilated panels facilitates airflow for thermal management. The unit slides directly into standard 19-inch racks using conventional guide rails. Its front panel features output status LEDs and a power ON/OFF switch.

Connector Interfaces and Field Wiring

A 10-position terminal block handles all input and output connections on the front face. This block accepts wire gauges from 0.5 mm² to 4.0 mm² for secure terminations. Separate terminals provide earth ground, AC input, and each DC output connection. The module includes strain relief clamps to protect wiring from vibration. Additionally, color-coded labels simplify installation and prevent wiring errors.

Internal Components and Energy Storage

The printed circuit board contains one main transformer, six rectifier diodes, and eight filter capacitors. A 2200 µF capacitor bank provides energy storage for the 5 VDC output channel. The 24 VDC output uses a 1000 µF capacitor for transient load handling. A separate 470 µF capacitor filters the 12 VDC auxiliary output. These capacitor banks ensure stable voltage during momentary load changes and power dips.

Protection and Safety Features

The NP1S-91/81 includes overvoltage protection on all output channels. It also provides short-circuit protection with automatic recovery upon fault clearance. Thermal shutdown activates when the internal temperature exceeds 85°C. An input fuse protects against overcurrent events and catastrophic failures. These protective features safeguard both the power supply and connected loads from damage.

Status Indication and Alarm Outputs

Three front-panel LEDs indicate the operational status of each output channel individually. Green LEDs confirm normal output while red LEDs signal overvoltage or short-circuit faults. The module provides a relay contact for remote power-fail alarming. This relay opens when any output voltage falls below 90% of its nominal value. Maintenance teams receive immediate notification for preventive action.

Environmental Specifications and Compliance

The NP1S-91/81 operates effectively in temperatures from 0°C to 55°C. It withstands humidity levels up to 95% non-condensing without performance degradation. The module complies with UL 508 and IEC 60950 safety standards. Efficiency reaches 85% at full load, minimizing heat dissipation in enclosures. These specifications suit applications in automation panels, control rooms, and industrial machinery.

Technical Data Sheet – Fuji NP1S-91/81

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