Description
Component Snapshot At-a-Glance
- Model: WH1-2FF
- Alt. P/N: 1X00024H01
- Product Series: Ovation (Westinghouse/Emerson) DCS System Power
- Hardware Type: 500W AC/DC Power Supply Module (Redundant)
- Key Feature: Wide-range 100–240VAC input; 24VDC main + auxiliary outputs
- Primary Field Use: Powers Ovation controllers, I/O racks, and field instruments in power, refining, and heavy process plants; redundant pair deployment for no-break uptime
Emerson WH1-2FF
Hard-Numbers: Technical Specifications
- Input Voltage: 100–240VAC, 50/60Hz (full-range, no tap changes)
- Output Voltage: 24VDC main; 24VDC auxiliary (isolated)
- Max Output Power: 500W continuous (24VDC @ ~20.8A)
- Efficiency: >85% @ full load
- Operating Temperature: -20°C to +55°C ambient
- Isolation Rating: 1500VAC input-to-output
- Alarm Contacts: Form C (NO/NC) for overvoltage/overtemperature faults
- Mounting: DIN-rail or panel mount
- Dimensions (W×H×D): 107×180×402mm
- Weight: 3.1kg
- Certifications: Class I Div 2, ATEX II 3G; discontinued by OEM
The Real-World Problem It Solves
Ovation DCS racks used to rely on low-wattage, narrow-input PSUs that died during brownouts or voltage swells. Early 24V supplies lacked auxiliary outputs and alarm contacts, leaving racks dark with no advance warning.
Where you’ll typically find it:
- Fossil power plant Ovation control rooms (boiler, turbine, balance-of-plant racks)
- Refinery process units (distillation, cracking, sulfur recovery DCS cabinets)
- Pulp & paper mill machine control racks (high-vibration, high-humidity areas)
It delivers 500W of regulated 24V power with redundant aux output and fault alarming, eliminating unplanned rack shutdowns.
Hardware Architecture & Under-the-Hood Logic
This is a switch-mode PSU with active PFC, isolated flyback topology, and redundant OR-ing diodes for parallel operation. No onboard CPU; uses analog regulation + fault logic.
- EMI filter + rectifier stage converts 100–240VAC to DC bus voltage.
- Active power factor correction (PFC) boosts bus to ~380VDC for efficient switching.
- Isolated flyback converter steps down to 24VDC main output; current-limited to 22A.
- Secondary winding generates isolated 24VDC auxiliary output (5A max).
- Fault monitor tracks OVP, UVP, OTP, and overcurrent; triggers alarm contact and shuts down outputs on fault.
- Redundant diode OR-ing allows two units to share load; faulty unit drops off without affecting the other.
Emerson WH1-2FF
Field Service Pitfalls: What Rookies Get Wrong
Forcing Into DeltaV (Not Ovation) Racks
New techs mix with DeltaV KJ-series PSUs and try to plug it into DeltaV M-Series backplanes. Different pinout, voltage sense, and alarm logic—it won’t work and can damage both PSU and backplane.
- Field Rule: is Ovation-only. Match to Ovation 1X00024H01 part number; never intermate with DeltaV KJ1501X1-BC2.
Ignoring Auxiliary Output Loading
Installers daisy-chain too many field transmitters on the 24V aux output, pulling >5A and triggering overcurrent shutdown. Main output stays up, but field instruments go dark.
- Quick Fix: Limit aux output to 4A max; use separate PSUs for large transmitter banks.
Poor DIN-Rail Grounding
Techs mount the PSU on non-grounded DIN rail or skip chassis ground wire. This creates common-mode noise, analog signal drift, and occasional ESD trips in high-static areas.
- Field Rule: Bond DIN rail to cabinet earth ground; run 14AWG ground wire from PSU chassis to cabinet ground bus.
Commercial Availability & Pricing Note
Please note: The listed price is for reference only and is not binding. Final pricing and terms are subject to negotiation based on current market conditions and availability.
