Key Technical Specifications
| Parameter | Value |
|---|---|
| Part Number | 8444-1082 |
| Product Designation | MFR300-71M |
| Manufacturer | WOODWARD |
| Product Type | Protection Relay / Monitoring Module |
| Application Domain | Generator protection, turbine control systems |
| Integration | Designed for Woodward generator control panels |
| Mounting | Panel / control cabinet mounting |
| Condition | Obsolete / Surplus Stock |
Product Introduction
When a generator loses excitation or a bearing temperature spikes past the trip setpoint, the relay that catches it has about 20 milliseconds to decide whether the unit lives or dies. The WOODWARD 8444-1082 (designated MFR300-71M) is one of those relays. It sits inside Woodward generator protection panels, watching for abnormal conditions and pulling the trip circuit when something goes sideways.I’ve worked with MFR300-series modules on diesel gensets and small steam turbine packages. They’re not glamorous. No one writes white papers about protection relays. But when the plant is dark and the operator is sweating, this is the component that either saves your equipment or doesn’t. The MFR300-71M is a known quantity in older Woodward control panels — it does one job, it does it predictably, and it doesn’t need a firmware update to stay awake.One thing worth flagging: public documentation on this specific suffix (-1082) is thin. The MFR300 family covers a range of relay configurations, and the suffix determines the exact contact arrangement, pickup settings, and application. Don’t assume it’s interchangeable with other MFR300 variants without checking the nameplate and your panel drawings.
Quality SOP & Tech Pitfalls
The Lab Report (SOP)
Before this relay ships, a competent supplier should run through:
- Visual Inspection: Check for cracked housings, corroded terminals, or signs of thermal damage on the PCB.
- Coil Resistance Check: Measure coil resistance with a multimeter (Fluke 115 or equivalent) and compare against the OEM spec sheet. An open coil means a dead relay.
- Contact Continuity Test: Verify normally-open and normally-closed contact states with the coil de-energized and energized.
- Pickup/Dropout Verification: If test equipment is available, apply increasing voltage to confirm the relay picks up at the rated threshold and drops out cleanly below it.
- Insulation Resistance: Megger test between coil and contacts to confirm no breakdown path.
- Anti-Static Packaging: Ship in ESD-safe packaging with terminal covers installed.
The Engineer’s Warning (Pitfalls)
- Mixing up MFR300 suffixes. The MFR300 family has dozens of part number variants. They look identical from three feet away. I once watched a tech install an MFR300-71M in a slot that called for a different suffix — the contact arrangement was wrong, the trip circuit never closed, and the generator ran unprotected for two weeks before someone noticed. Always match the full part number, including the suffix, against the panel schematic.
- Ignoring coil voltage ratings. Some MFR300 variants are 24V DC, others are 110V or 220V. Wire the wrong voltage to the coil and you’ll either get a relay that won’t pull in, or one that burns out in seconds. Check the nameplate. Check it twice.
Installation & Configuration Guide
- Pre-Installation (⚠️ Safety First)
- Lock out all generator control power and trip circuit power. Verify zero energy with a calibrated multimeter.
- Photograph the existing relay’s position, terminal wiring, and any jumper or DIP switch settings. This is non-negotiable.
- Pull the panel drawing for the exact relay slot and confirm the required part number matches 8444-1082.
- Removal
- Label every wire connected to the old relay terminals.
- Remove mounting screws or DIN rail clips.
- Pull the relay straight out. Do not pry or lever it against adjacent modules.
- Installation
- Verify the replacement 8444-1082 matches the original in every way — full part number, coil voltage, contact configuration.
- Inspect terminal blocks for corrosion or loose screws.
- Seat the relay firmly and secure mounting hardware.
- Reconnect all wires to their original terminals per your photo documentation.
- Power-On & Testing
- Restore control power only. Verify the relay coil energizes (you should hear a distinct click).
- Check contact continuity in both states (energized and de-energized).
- If the panel has a built-in relay test function, run it.
- Perform a manual trip test under controlled conditions before returning the generator to service.
Compatible Replacement Models
| Model | Compatibility Tier | Notes |
|---|---|---|
| WOODWARD 8444-1082 (same part number) | ✅ Drop-in Replacement | Direct swap — verify coil voltage and contact arrangement match |
| WOODWARD MFR300 series (other suffixes) | ⚠️ Verify with OEM | Same product family but different suffixes may have different contact configurations or coil ratings — not guaranteed interchangeable |
| Third-party protection relays | ❌ System redesign required | Different mounting, wiring, and logic integration — not a drop-in swap unless the panel was designed for it |
Frequently Asked Questions (FAQ)
Q: Is this relay still manufactured by Woodward?
No. The 8444-1082 is a legacy product. What’s available on the market is surplus stock — either new-old-stock from warehouse clearance or tested used units pulled from decommissioned panels. Ask the supplier for test reports and condition documentation before buying.Q: Can I substitute a different MFR300 suffix if I can’t find the -1082?
Not without verifying the contact arrangement and coil voltage. The MFR300 family uses the same physical form factor across variants, but the internal contact configuration and electrical ratings differ by suffix. A wrong suffix can leave your trip circuit open when you need it closed. Check the panel schematic and the OEM datasheet before swapping.Q: How do I know if this relay has failed?
Common signs: the relay doesn’t click when the coil is energized, the trip circuit doesn’t close when it should, or you measure an open coil on a resistance check. If the generator has been tripping unexpectedly, check the relay contacts for pitting or welding — high-current switching over years can degrade contact surfaces.Q: What’s the coil voltage on this relay?
The public data doesn’t specify it for the -1082 suffix. Check the nameplate on the relay itself — the coil voltage is printed there. Common MFR300 variants run on 24V DC, 48V DC, 110V DC, or 220V DC. Do not guess.Q: What’s the typical lead time for a surplus unit?
It depends on what’s sitting in someone’s warehouse. These relays don’t have a production line anymore. If a supplier has it in stock, it ships same-day. If they need to source it, expect a few days to a week. For a critical generator protection relay, I’d recommend contacting multiple surplus suppliers simultaneously and asking for tested units with documentation.Q: Can I test this relay in-circuit without pulling it?
You can check coil voltage and contact states with a multimeter while the panel is energized — but be careful. You’re working near live trip circuits. If you need to do a full pickup/dropout test, pull the relay and bench-test it. It takes five minutes and saves you from accidentally tripping the generator during testing.
