Product Core Brief
- Model: PW484-50 S1
- Brand: Yokogawa
- Series: ProSafe-PLC / ProSafe-RS Power Supply Module
- Core Function: 24V DC input power supply for Yokogawa safety controller racks.
- Product Type: DC Power Supply Module
- Key Specs: 24V DC input | Dual-redundant capable | -20°C to 70°C operating range
- Condition: New Original / New Surplus
Key Technical Specifications
- Manufacturer: Yokogawa
- Part Number: S1
- Module Type: DC Power Supply Module
- System Family: ProSafe-PLC / ProSafe-RS safety system
- Input Voltage: 24V DC
- Suffix Code -5: Standard type with no explosion protection
- Suffix S1: Revision / manufacturing variant; must match system acceptance requirements
- Redundancy: Dual-redundant configuration supported (two identical modules with same suffix code)
- Temperature Range: -20°C to 70°C
- Output: Internal +5V / +24V DC bus for rack and I/O modules
- Status Indicators: PWR, +5V, +24V, CHECK, GND (module-dependent)
- Mounting: DIN-rail / backplane-mounted in Yokogawa safety rack
- Typical Applications: ESD racks, burner management systems, compressor protection, 24V DC safety controller power feeds, remote skids with DC distribution
Product Introduction
The PW484-50 S1 is a Yokogawa 24V DC power supply module used in ProSafe-PLC and ProSafe-RS safety systems. It converts an external 24V DC supply into regulated internal bus power for the controller rack and associated I/O modules, making it a common fit for cabinets that already use DC distribution or require redundant DC feeds.
Its main advantage is direct compatibility with 24V DC safety racks and support for dual-redundant operation. For maintenance and procurement teams, this is a direct-fit OEM replacement part that supports existing cause-and-effect documentation, loop checks, and plant acceptance testing without reworking power distribution.
QA & Testing SOP
DC power supplies require the same discipline as AC units, but the failure modes are different. A bad 24V DC feed can look like a field wiring fault if the supply is not tested under load.
- Label and authenticity check: Verify part number, suffix code (-50), S1 revision, serial number, and manufacturing markings against OEM references.
- Visual inspection: Check DC terminal block, backplane connector, housing, fuses, capacitors, and PCB for heat damage, corrosion, or rework.
- DC input test: Apply 24V DC on a bench test rack and verify normal power-up sequence with no abnormal noise or heating.
- Output verification: Measure internal +5V and +24V DC bus rails with a Fluke-class multimeter and confirm they remain within specification under load.
- Redundancy check (if applicable): If two units are available, verify dual-redundant operation and failover behavior on a ProSafe test rack.
- ESD-safe packing: Ship in anti-static packaging with terminal and backplane protection, plus label photos for receiving QA.
Installation Pitfalls & Guide
❗ Confirm input voltage before installation. The PW484-50 is a 24V DC module. Connecting it to an AC supply or the wrong DC voltage will damage the unit. For 100-120V AC systems, the PW481 series is used; for 200-240V AC, the PW482 series is used.
❗ Do not hot-swap without procedure. Removing or inserting a power supply can disturb the safety rack bus and cause an unintended trip. Follow plant MOC and safety system procedures.
❗ Match suffix codes for redundancy. Dual-redundant configuration requires two identical modules with the same suffix code and revision. Mixing different suffixes or revisions can cause uneven loading, diagnostic faults, or failed failover.
❗ Verify the S1 revision. The S1 suffix may indicate a manufacturing revision or variant. Confirm with your system documentation or Yokogawa references before substituting it for a non-S1 unit.
Replacement steps:
- Pre-install: Confirm input voltage, suffix code, S1 revision, rack position, redundancy configuration, and ESD precautions.
- Removal: Follow safety system procedures, isolate DC power if required, label wiring, and remove the module.
- Install: Seat the module firmly, reconnect DC wiring, and verify terminal torque and grounding.
- Power-on test: Restore DC power, check status LEDs, measure DC bus outputs, and confirm rack diagnostics are normal. If redundant, verify failover behavior.
Technical FAQ
Is pricing flexible? Yes. Price depends on condition, stock availability, label completeness, S1 revision, test records, and whether the unit is new original or new surplus. Urgent shutdown replacements can be prioritized.
What warranty is included? Surplus power supply modules usually carry a limited functional warranty, often 30–90 days, unless otherwise agreed. Final terms depend on stock source and customer QA requirements.
Can this replace a PW481-50 or PW482-10? No. The PW484-50 is a 24V DC input module, while the PW481 series is for 100-120V AC and the PW482 series is for 200-240V AC. Substituting the wrong voltage type will cause operational failure or damage.
Does it support dual-redundant configuration? Yes. The PW484-50 supports dual-redundant operation when two identical modules with the same suffix code and revision are installed. This is a common configuration in high-availability safety racks.
What does the S1 suffix mean? The S1 suffix typically indicates a manufacturing revision or variant. It should be confirmed against your system documentation before substitution. In many cases, S1 units are backward compatible, but this must be verified per plant acceptance rules.
