Phoenix Contact QUINT-PS/1AC/24DC/5 2866750 QUINT-PS Spare

Phoenix Contact QUINT-PS/1AC/24DC/5 2866750 QUINT-PS Spare: Spare Parts Replacement and Industrial Downtime Risk Control

The Phoenix Contact QUINT-PS/1AC/24DC/5 (Part No. 2866750) is a single-phase 24 VDC / 5 A DIN-rail-mounted power supply unit from the QUINT-PS series — one of the most widely deployed primary-switched PSU families in industrial control cabinets worldwide. When this unit reaches end-of-life, develops output ripple beyond tolerance, or triggers nuisance tripping on its integrated SFB (Selective Fuse Breaking) circuit, unplanned downtime follows quickly. Stocking a verified replacement spare is the single most effective measure a maintenance team can take to protect continuous operation in PLC-driven and DCS-integrated automation systems.

This listing provides an original-specification QUINT-PS/1AC/24DC/5 2866750 unit, tested prior to dispatch, supplied with a 12-month warranty, and ready for same-day or next-day shipment. Each unit is verified against Phoenix Contact’s published electrical parameters before leaving our facility, ensuring drop-in compatibility with existing QUINT-PS wiring, DIN-rail mounting, and downstream 24 VDC load circuits.

Spare Maintenance Table

Maintenance Planning for Continuous Operation

A QUINT-PS/1AC/24DC/5 2866750 replacement should never be treated as an isolated swap. Experienced maintenance engineers know that a failed or degraded power supply often masks — or is caused by — stress in adjacent components sharing the same 24 VDC bus or the same control cabinet. When scheduling a planned replacement or responding to an emergency shutdown, the following components should be inspected or staged as concurrent spares.

Begin at the input side: verify the upstream AC input fuse or circuit breaker feeding the QUINT-PS unit. A blown or weakened fuse is frequently the root cause of apparent PSU failure. Next, check the QUINT-DIODE/2X10 or equivalent redundancy module if the installation uses a parallel redundant PSU configuration — a failed diode module can cause one supply to carry the full load, accelerating wear. On the DC output side, inspect the QUINT-BUFFER/24DC/40 or similar UPS buffer module if installed; buffer capacitors degrade over time and may no longer provide the hold-up time required during brief AC interruptions.

Within the same cabinet, examine the Phoenix Contact QUINT-PS/1AC/24DC/10 or QUINT-PS/3AC/24DC/20 units if the installation uses multiple PSU rails — a common failure pattern is cascading load imbalance when one rail drops. Terminal blocks, particularly the PT 2.5 and PT 4 series from the same Phoenix Contact ecosystem, should be checked for loose connections and discoloration indicating thermal stress. Surge protection devices such as the TRABTECH PT-IQ-2X2-24DC-ST should be inspected for status indicator changes, as a sacrificed SPD can allow transient energy to reach the PSU input.

On the PLC or DCS side powered by this supply, verify that the CPU module — whether a Siemens S7-300 PS 307, an Allen-Bradley 1756-PA75, or a comparable rack power supply — is receiving stable 24 VDC within tolerance. I/O modules, particularly analog input cards sensitive to supply ripple, should be checked for erratic readings that may have preceded the PSU fault. Communication modules such as PROFIBUS DP or PROFINET interface cards can exhibit intermittent disconnects when supply voltage dips below 22 VDC, so reviewing event logs before and after replacement is recommended. Signal isolators and loop-powered transmitters on the 24 VDC bus should also be verified for correct output after the new PSU is energized.

Finally, if the control cabinet includes a Phoenix Contact QUINT-PS/1AC/24DC/5 as the sole supply for a safety relay circuit — such as a PNOZ or PSR series safety relay — confirm that the safety relay’s self-monitoring function passes its diagnostic cycle after the PSU swap before returning the machine to production.

Site Replacement Workflow

Replacing the QUINT-PS/1AC/24DC/5 2866750 on-site is a straightforward procedure when the correct spare is pre-staged and the replacement workflow is followed systematically to minimize downtime.

Step 1 — Pre-replacement verification: Confirm the replacement unit’s part number (2866750) and output voltage setting match the installed unit. Check the output voltage trim potentiometer position on the failed unit before removal and replicate it on the new unit.

Step 2 — Safe isolation: De-energize the AC input using the upstream circuit breaker or disconnect. Verify absence of voltage on both AC input terminals and DC output terminals using a calibrated multimeter before touching any wiring.

Step 3 — Wiring documentation: Photograph or sketch the terminal connections — L, N, PE on the AC side; +24V and 0V on the DC output; and the DC OK relay terminals if wired. The QUINT-PS/1AC/24DC/5 uses Phoenix Contact’s push-in or screw terminal technology; note the wire cross-sections to ensure correct re-termination.

Step 4 — Mechanical removal and installation: Release the DIN-rail locking tab, slide the unit off the rail, and install the replacement. Reconnect all terminals in reverse order, torquing screw terminals to the specified 0.5–0.6 Nm to prevent loose connections under vibration.

Step 5 — Energization and verification: Apply AC power and confirm the green DC OK LED illuminates. Measure output voltage at the load terminals. Verify the DC OK relay contact closes and any remote monitoring system acknowledges the healthy status signal. Check downstream PLC or DCS modules for normal operation before releasing the system to production.

This workflow is compatible with replacing older QUINT-PS/1AC/24DC/5 units manufactured under earlier Phoenix Contact catalog revisions, as the 2866750 part number covers the current production standard with backward-compatible terminal layout and DIN-rail footprint.

Spare Parts Support FAQ

Q1: Is this unit a genuine original Phoenix Contact QUINT-PS/1AC/24DC/5 2866750, or a compatible substitute?
This listing supplies original-specification units sourced to match Phoenix Contact’s published electrical and mechanical parameters for the 2866750 part number. Each unit is tested for output voltage accuracy, ripple, and DC OK relay function before dispatch. If you require OEM factory-sealed packaging, please contact us to confirm current stock availability.

Q2: What is the recommended spare parts inventory strategy for QUINT-PS/1AC/24DC/5 units in a multi-cabinet installation?
Industry best practice for critical 24 VDC supply rails is to maintain a minimum of one spare unit per five installed units, or one spare per cabinet if the installation is safety-critical. For facilities with extended lead times from local distributors, holding two units on-site eliminates the risk of a second failure during the procurement cycle following the first replacement.

Q3: How is the unit tested before shipment, and what does the 12-month warranty cover?
Each QUINT-PS/1AC/24DC/5 2866750 unit undergoes pre-shipment functional testing: AC input energization, output voltage measurement at no-load and full-load (5 A), DC OK relay continuity check, and visual inspection of terminals and housing. The 12-month warranty covers manufacturing defects and electrical performance failures under normal operating conditions. It does not cover damage from incorrect installation, overvoltage events, or operation outside the specified input voltage range.

Q4: Can this unit replace an older QUINT-PS/1AC/24DC/5 with a different catalog suffix or earlier production date?
Yes. The QUINT-PS/1AC/24DC/5 2866750 is the current production part number for this model and is backward compatible with earlier production variants sharing the same DIN-rail footprint, terminal layout, and 24 VDC / 5 A output specification. If your installed unit carries a different suffix or an older catalog number, please share the nameplate data with us before ordering so we can confirm compatibility.

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