Yokogawa PW481-50

DC Input Electrical Parameters

Multi-Channel DC Output Parameters

Physical & Mechanical Parameters

Environmental Operating Parameters

Safety & EMC & Functional Safety Certification Standards

Function & Feature Highlights

1. Dual-module parallel hot redundant operation support, two PW481-50 modules installed in the same DCS rack operate in load-sharing mode under normal working state, each module bears 50% of total rack power supply load; when one module suffers any fault shutdown, the other standby module automatically bears 100% full load within 2ms without any power supply interruption to DCS rack modules, meeting zero power interruption requirement of high-reliability continuous production process equipment.
2. 48 VDC DC input design matching industrial emergency backup power system, industrial 48 VDC backup battery power supply can be connected directly to the module input terminal, when factory AC main power grid suffers power failure, the 48 VDC backup battery group can continue to supply power to DCS rack through PW481-50 module to maintain continuous operation of process control system without equipment emergency shutdown and production loss.
3. Ultra-high power conversion efficiency up to 91% under rated full load state, low internal power loss and heat generation, reducing heat dissipation load of control room air-conditioning equipment and lowering long-term factory operation energy consumption cost.
4. Built-in independent multi-stage hardware protection circuit for input side and each output channel, integrating input reverse polarity protection, input undervoltage/overvoltage protection, output overvoltage/undervoltage protection, output overcurrent protection and output short-circuit protection six types of fault protection logic. When single output channel short-circuit fault occurs, only the faulty channel cuts off power output, other DC voltage channels maintain stable power supply to ensure normal operation of core redundant CPU and communication modules.
5. Front panel multi-group independent LED status indicator and digital fault code display window, including green power normal LED, red input fault LED, yellow output overload alarm LED, blue redundant synchronous state LED; 3-digit digital display window can display real-time input voltage value, each channel real-time output current value and fault code information, maintenance personnel can read detailed module operating data and fault cause information directly from front panel without disassembling the module or using external measuring instruments.
6. Built-in internal module temperature real-time monitoring and automatic power derating logic, when the internal temperature rises above 62 ℃, the module automatically reduces maximum total output power by 20% to reduce internal power loss and heat generation; when the temperature exceeds 68 ℃, the module automatically triggers over-temperature protection to cut off all DC output power to prevent internal high-power power components thermal breakdown damage.
7. Hot-swappable modular design, PW481-50 module can be pulled out and replaced when the DCS rack is in continuous normal operation without cutting off the entire cabinet power supply, during redundant module replacement process, the other standby module continuously undertakes all rack power supply load without power supply interruption, greatly shortening maintenance downtime of high-reliability continuous production process equipment.

Material & Structural Composition

1. Outer Shell Material: High-strength flame-retardant ABS+PC alloy plastic with reinforced glass fiber filler, UL94 V-0 fire resistance rating, excellent anti-aging, anti-corrosion and impact resistance performance to adapt to large petrochemical plant control room harsh environment.
2. Main Power Circuit Substrate: Six-layer high Tg FR4 copper-clad circuit board, extra thick copper foil layer for high-current power transmission loop to minimize conduction heat generation and voltage drop under full load high-current operation state.
3. Isolation Energy Conversion Components: Large-capacity high withstand voltage high-frequency isolation switching transformer, primary and secondary winding separated by multi-layer thick mica insulation paper to meet 2500 VAC high voltage isolation safety requirements; high-power fast recovery rectifier bridge stacks and low ESR high-capacity filter electrolytic capacitors imported from Japanese top-tier electronic component manufacturers.
4. Heat Dissipation Structure Components: Ultra-large area extruded aluminum alloy heat sink installed on the back of the module, connected to high-power switching power tubes and rectifier bridge stacks through high thermal conductivity silicone pads; dense strip heat dissipation ribs distributed on the left and right side panels of the module to maximize natural convection heat dissipation efficiency without auxiliary cooling fan, zero mechanical wearing parts.
5. Backplane Connection Components: Large-capacity spring-type gold-plated backplane connector with 0.35μm thick gold plating on contact surface, effectively prevent long-term plug-in contact oxidation and reduce contact resistance under high-current transmission state.
6. Internal Auxiliary Insulation Materials: Thick mica insulation sheets between 48 VDC high-voltage input circuit and low-voltage DC output circuit; flame-retardant plastic isolation partitions between each output channel circuit to completely avoid cross-channel short-circuit risk caused by internal component breakdown failure.

Working Principle

1. 48 VDC Input Filter & Reverse Polarity Protection Stage: External industrial 48 VDC main power or backup battery power enters the PW481-50 module’s input filter circuit first to filter DC power high-frequency ripple noise. The filtered 48 VDC voltage passes through built-in hardware anti-reverse connection circuit, which automatically isolates circuit loop when input positive and negative polarity wiring is reversed to protect internal power components from breakdown damage. The processed 48 VDC voltage is transmitted to primary side filter capacitor group for voltage smoothing treatment.
2. High-Frequency Switching Energy Conversion Stage: The smoothed 48 VDC power supply drives high-power high-frequency switching power tubes to perform PWM pulse width modulation switching action controlled by multi-channel dedicated power management chip. The high-frequency pulse energy generated by high-current switching action is transmitted to each secondary winding coil of the large-capacity isolation transformer through electromagnetic induction coupling.
3. Multi-Channel DC Voltage Stabilization Output Stage: Each secondary winding coil corresponds to an independent high-current rectifier filtering and precision voltage stabilization circuit. The alternating pulse voltage induced by secondary winding is converted into smooth stable DC voltage through high-power fast recovery rectifier bridge stack and low ESR large-capacity filter electrolytic capacitor group. The built-in high-precision voltage sampling feedback circuit collects real-time output voltage value of each channel and feeds it back to the primary side PWM control chip to adjust switching pulse duty cycle in real time, realizing constant stable DC voltage output under wide range variable load conditions of large DCS rack high-density I/O modules.
4. Redundant Module Synchronous Load-Sharing Control Stage: When two PW481-50 modules are installed in parallel redundant mode in the same DCS rack, the redundant synchronous communication circuit on the backplane connector transmits real-time load current data between two modules, the built-in load-sharing control chip automatically distributes rack total power supply load evenly to two modules to realize 50% load sharing operation state; when one module suffers fault shutdown, the synchronous communication circuit transmits fault signal to the other standby module instantly, the standby module automatically adjusts internal PWM control logic to increase total output power to bear 100% full rack load within 2ms without power supply interruption.
5. Real-Time Multi-Dimensional Fault Monitoring & Protection Execution Stage: Dedicated multi-channel sampling circuits continuously monitor 48 VDC input voltage, each channel DC output voltage, each channel real-time output load current and module internal operating temperature. When any abnormal threshold is triggered, the corresponding hardware protection circuit instantly locks the PWM driving signal of all high-frequency switching power tubes to cut off energy transmission of the isolation transformer, and the module front panel corresponding fault LED indicator lights up synchronously, 3-digit digital display window shows specific fault code information; meanwhile, fault state signal and fault code data are transmitted to DCS rack backplane bus, uploaded to upper-level CENTUM VP operation monitoring screen to display detailed fault information and trigger system multi-level sound and light alarm reminder for maintenance personnel rapid fault location and troubleshooting.