HONEYWELL SPS5710 | TDC 3000 Power Supply – 5 V / 24 V

Description

Product Introduction

The processor rack goes dark. No LEDs. No communication. The operator says the whole unit just died. You walk to the back of the cabinet and see the SPS5710’s fan is silent.

The HONEYWELL SPS5710 is the big power supply—the one that runs the processor, the I/O, and the comm cards in a TDC 3000 rack. +5 V at 25 A for the logic, ±15 V for the analog circuits, +24 V for the field loops. It’s a 250 W beast with a fan that keeps it cool. When it dies, everything dies with it.

I’ve pulled these out of refineries where they’d been running for 20 years. The fan seizes. The caps bulge. The output starts to sag. One plant had an SPS5710 that was putting out 4.7 V on the 5 V rail—the processor was still running but the I/O was glitching. They spent three days chasing “random” faults before someone checked the power supply with a scope.

Key Technical Specifications

Quality Inspection Process (SOP Transparency)

This supply gets the full treatment. Too much rides on it.

1. Incoming Verification
   This batch came from a Honeywell service center surplus. Original boxes. Serial numbers traceable to 2005–2008 production.
2. Visual Inspection
   First: the fan. Spin it with a pencil—should turn freely. Any resistance is a fail. Next: the electrolytic caps. Look for bulging, venting, or leaking. Also check the input terminal block for burn marks.
3. Live Functional Test
   We test the SPS5710 on a bench with a resistive load bank. Procedure:
   • Power‑up: verify fan runs, all output LEDs light
   • +5 V: apply 25 A load for 30 minutes, measure voltage (must stay >4.85 V)
   • +5 V ripple: <50 mV p-p at full load
   • +15 V: apply 2.5 A load, measure voltage (14.7–15.3 V)
   • –15 V: same test
   • +24 V: apply 2.5 A load, measure voltage (23.5–24.5 V)
   • Overcurrent test: increase +5 V load to 30 A, verify supply shuts down or current limits
   • Thermal soak: run all outputs at 80% load for 2 hours, monitor temperatures
4. Fan Test
   Run the unit at full load for 1 hour. Verify fan runs continuously. Any fan noise (grinding, clicking) is a fail.
5. Final QC & Packaging
   Passed units go back in anti‑static bags, then bubble wrap, then a carton with QC sticker showing test date, load test results, and fan verification.

Field Replacement Pitfalls

The big supply powers everything. Mistakes here take down the whole rack.

1. Fan failure.
   The fan is the first thing to go. The unit will still run—for a while. The caps overheat, the outputs get noisy, and the processor starts glitching. I’ve seen a plant with random processor resets that traced back to an SPS5710 with a dead fan. The supply passed a voltage check. It failed the thermal test. Listen for the fan. If it’s silent, swap the unit.
2. ❌ Load distribution.
   The +5 V rail is rated for 25 A. If you’re pulling 28 A, the supply will run hot. It might not trip. It’ll just die slowly. I’ve seen a plant with a TDC 3000 rack packed with cards—they added one more and the supply lasted six months. The fix was moving some cards to a second rack. Calculate the total load before you add cards.
3. Ripple kills the processor.
   A failing supply can still put out 5 V but have 200 mV of ripple. The processor will run—until the ripple spikes and it resets. I’ve seen a plant with intermittent processor faults that traced back to an SPS5710 with bad output caps. The voltage was fine. The scope told the story.
4. Grounding.
   The outputs share a common ground with the rack. If you have a ground loop in the field wiring, you’ll see noise on the 5 V rail. The processor will be fine. The analog inputs will bounce. I’ve seen a plant with jumpy analog readings that traced back to a ground loop, not the power supply.
5. Input voltage.
   The SPS5710 auto‑ranges. It’ll take 120 or 240 VAC. But if the input voltage drops below 100 VAC, the supply will still run—the outputs will sag. I’ve seen a plant with low line voltage that caused the processor to reset every afternoon when the plant load peaked. The supply was fine. The grid was the problem.

Get these five right and you’ll cut rework time by 90%.

New Original vs. Refurbished: Why It Matters

“New Original (New Surplus)” means this HONEYWELL SPS5710 was built by Honeywell, never installed, and never repaired. The caps are from the original production run. The fan has zero hours. The output has never been shorted.

Refurbished TDC 3000 power supplies are risky. The electrolytic caps are the weak point. A refurb unit may have had the caps replaced—or it may not. I’ve seen refurb units that passed a voltage check but failed the load test after 20 minutes. The caps were original from 1998. They were done. The supply was sold as “tested working.”

What we provide:

• Traceable serial number (matches Honeywell production records)
• 30‑minute load test at full rated current on all outputs
• Ripple measurement per output
• 2‑hour thermal soak at 80% load
• Fan operation verification
• Original anti‑static bag (if available) or fresh bag with QC seal
• 12‑month warranty

Pricing context:
Our price sits above the cheapest used listings. It’s also below what a new supply would cost if Honeywell still made them. You’re paying for the test, the warranty, and the certainty that the caps aren’t going to fail next month.

Performance Benchmarks & Test Results

All tests performed at 25 °C ambient, 120 VAC input, full rated load.

Thermal performance note:
At 50 °C ambient, the internal temperature hits 75–80 °C. The fan runs continuously. If the fan fails, the unit will overheat and trip in about 15 minutes. We’ve seen that in the field. Replace the fan if it’s noisy or slow.

One more thing from the field:
The SPS5710 has a small test point on the front—TP1. It’s the 5 V reference for the regulators. If the outputs are off but within spec, probe TP1. Should be 5.0 ±0.05 V. If it’s drifting, the whole supply is aging. I’ve seen a plant with an SPS5710 that passed all load tests but had a TP1 reading of 4.85 V. Six months later, the 5 V rail started sagging. They caught it early. You can too.

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