What it is and why it matters on the BOM
The Mitsubishi FX2N-48ER-ES/UL is a compact PLC base unit in the FX2N family, carrying 24 DC inputs and 24 relay outputs on a single 100-240 VAC supply — the unit that the cabinet gets built around when this FX-series footprint is on the BOM. I/O terminate on removable M3-screw terminal blocks at both the input and output ends, so a swap with a known-good spare (or a seasonal-output-stage rebuild) is a screwdriver operation rather than a wire-cut job. It drops into mixed FX-family installations: the unit is qualified as an application sequencer against the FX1N, FX3G, FX2N, and FX3U families, so a panel that has migrated generations can keep its I/O mapping intact.
Inputs — what the field-side card actually sees
Inputs accept DC 24 V ±10% in either sink or source wiring, drawing 5 mA at 24 VDC through a 4.3 kΩ input impedance — so a standard sensor barrel (PNP or NPN open-collector, or volt-free contact) lands on the same block without a rewire. The minimum-load reference is DC 5 V at 2 mA, which is the floor for a clean OFF-to-ON transition; mechanical reed switches and low-leakage sensors sit comfortably above this. Input response is about 10 ms in either direction, with photocoupler isolation between the field-side terminal and the internal logic. An on-panel LED per input confirms power-on state for the commissioning engineer walking the FAT — no meter required.
Outputs and 24 VDC service supply
All 24 outputs are volt-free relay contacts rated for inductive loads up to 80 VA, with an external switching envelope of 30 VDC or 240 VAC (250 VAC where CE / UL / cUL compliance is not at issue). The unit supplies its own 24 VDC service rail at up to 460 mA for sensor excitation and annunciator loops, but the rail is consumed by any input/output extension block that gets added — budget accordingly when adding an FX2N-16EX-ES/UL-class expander.
Power budget, environment, and protection
Mains side runs on AC 100 V to 240 V (tolerance 85-264 V) at 50/60 Hz, drawing 35 W with a 5 A / 250 V fuse on the supply — inrush on cold start is capped at 40 A (100 V) or 60 A (200 V) for ≤5 ms, so a standard C-curve breaker upstream is sufficient. Dielectric withstand is 1500 VAC for one minute between the AC power terminal and ground, and 500 VAC between the 24 VDC rail and ground, with 500 MΩ insulation resistance per terminal to earth — the numbers a safety auditor will read first. Operating envelope is 0–55 °C at 5–95% RH non-condensing, with storage to -25–75 °C, and impact tested at 147 m/s² for 11 ms to IEC 61131-2 sine half-wave per X/Y/Z — adequate for panel-mount, light-vibration industrial floors; pressurised-altitude use (≤2000 m absolute) is the documented hard boundary.
Second-source question — does this drop in for FX2N-16EX-ES/UL
No: the FX2N-16EX-ES/UL is an input expansion block, not a CPU/base unit. It cannot be substituted for a 48ER base — a panel that has the 48ER on its BOM line needs the 48ER, full stop. They sit on the same FX2N backplane family and can co-exist (the 16EX as an expander), but they are not cross-shop candidates.
Compliance documentation
The order code suffix /ES/UL denotes CE, UL, and cUL compliance on the underlying spec, with the note that AC 250 V external switching only applies where CE/UL/cUL is not in scope — a buyer should be ready to show the nameplate to a CE/UL inspector rather than rely on spec-sheet language alone. Dielectric test voltages (1500 VAC / 500 VAC) and IEC 61131-2 impact criteria are the documented compliance envelope; explicit RoHS / REACH statements are not on the spec sheet and would need to be sourced from the factory documentation pack on the unit's nameplate.