Schneider Electric 140XBP00400 – Modicon Quantum 4‑Slot Backplane for Compact PLC Racks

The 140XBP00400 is the 4‑slot backplane for Schneider Electric’s Modicon Quantum platform, ideal when you need a reliable, space‑saving rack for a CPU, power supply, and a small set of I/O or network modules. It’s typically used in smaller machine cells, pilot systems, or as a local expansion rack where cabinet space is at a premium.

From my experience, it’s a clean way to keep a Quantum node lean without sacrificing serviceability or module compatibility. You keep the proven Quantum stability while avoiding an oversized chassis for just a handful of modules.

• 4-slot Quantum form factor – Fits a 140CPS power supply, 140CPU, and up to two I/O/communication modules in a compact footprint.

• Native Modicon Quantum backplane bus – Works with standard 140‑series modules (CPU, power, I/O, and comms) for straightforward integration.

• Panel-mount ready – Designed for control cabinet mounting; no special frames required, typically lighter than large racks.

• Stable 5 V bus distribution – Bus power provided by the installed 140CPS power supply; capacity depends on the PSU selected (no separate backplane supply needed).

• Service-friendly layout – Clear slot arrangement (power supply at the left, CPU adjacent) helps with wiring discipline and quick maintenance.

• Backwards compatibility – Suits installed-base upgrades and spare-part strategies where Quantum remains the site standard.

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This backplane is a good fit for compact automation nodes that still need Quantum-grade reliability. You might notice it used frequently where a small but robust controller footprint is preferred.

• OEM machine skids with limited cabinet space

• Water & wastewater lift stations and small process cells

• Power generation auxiliaries and sub‑systems

• Oil & gas well pads, metering skids, and compact RTU‑style cabinets

• Brownfield sites maintaining an installed Quantum standard

• Right‑sized footprint – Avoids paying for and populating unused rack slots; helpful when enclosure depth is tight.

• Compatibility and longevity – Supports a wide range of 140‑series modules, aiding spares strategy and minimizing re‑engineering work.

• Lower lifecycle cost – Fewer modules to power and cool; easier to maintain. In many cases, it reduces downtime during servicing.

• Clear migration path – Many sites keep the 4‑slot as a local node while planning phased modernization, which seems to be the least disruptive approach.

“We swapped a bulky 8‑slot rack for the 140XBP00400 in a dosing skid—same CPU and comms, half the space, and wiring was far cleaner.” — Maintenance Supervisor, food & beverage plant

• Cabinet & mounting – Mount on a rigid backplate with proper earthing. Provide clearance for wiring and module removal. Not intended for DIN rail.

• Ventilation – Maintain airflow around the rack; keep ambient within the typical 0–60 °C range and below 95% RH non‑condensing.

• Power sizing – Choose a 140CPS power supply with adequate 5 V current headroom for all installed modules; verify load with Schneider’s sizing guidelines.

• Wiring discipline – Separate power and signal wiring; use shielded cables where required by I/O modules; tighten all grounding points.

• Safety & ESD – De‑energize before adding/removing modules; use ESD protection when handling boards and connectors.

• Routine checks – Inspect backplane connectors for dust; clean with dry air. Firmware updates apply to CPU/comms modules, not the backplane itself.

• CE and UL/CSA certifications (typical for Modicon Quantum hardware)

• RoHS compliance for environmental requirements

• Manufacturer warranty: typically 18 months from shipment (standard Schneider Electric policy)

Note: If you anticipate growth beyond two I/O/communication modules, consider moving to 8, 10, 12, or 16‑slot Quantum backplanes (e.g., 140XBP00800, 140XBP01000, 140XBP01200, 140XBP01600) to avoid rework later.