SMC INR-244-755 Power Supply Unit

SMC INR-244-755 — Your Valve Island Is Down. We Ship Today.

A failed INR-244-755 doesn’t just kill one valve — it takes the entire EX-series manifold island offline. No outputs. No fieldbus communication. Production stopped. If you’re reading this during a breakdown, here’s what matters: we have this unit in stock at our Xiamen warehouse, we’ve shipped it to over 40 countries, and we can have it moving toward your site within hours of order confirmation. Not a promise — a process we run every working day.

This is a 100% original SMC INR-244-755, sourced through verified supply channels, inspected before packaging, and shipped with full commercial documentation. No refurbished units. No remarked parts. No surprises at customs.

⚡ URGENT REQUIREMENT? Contact: [email protected] | WhatsApp: +86 18359268345

Quick Technical Datasheet

Troubleshooting & Replacement Tips

The INR-244-755 is the sole power source for the logic and communication circuits inside SMC EX-series manifold islands. When it degrades or fails hard, the entire island drops — every solenoid output goes dead simultaneously, and the fieldbus coupler loses power before it can even report a fault code to the PLC. This is the failure mode that catches engineers off guard: the PLC sees a communication loss, not a power fault, and the diagnostic trail goes cold fast.

Failure Signatures to Confirm Before Ordering:

• All solenoid outputs on the manifold island drop at once — not a single-valve fault pattern. If only some valves are dead, the INR-244-755 is not your problem; investigate the solenoid driver board or wiring harness instead.
• PLC reports fieldbus communication timeout or node loss for the EX coupler. The coupler hardware is intact — it’s simply unpowered.
• PWR LED on the EX coupler is off, amber, or flashing red. A solid green PWR LED with other faults present means the supply is working; look elsewhere.
• Intermittent resets under peak load — multiple solenoids energizing simultaneously causes inrush that a marginal supply cannot sustain. The island resets, recovers, then fails again under the next load spike.
• Thermal shutdown pattern: island runs fine for 30–60 minutes then drops. Cabinet ambient above 45 °C combined with a degraded supply is a classic combination.

Step-by-Step Replacement Procedure:

• Step 1 — Isolate: Remove 24 VDC supply input to the INR-244-755 at the terminal block. Do not rely on PLC output disable or E-stop alone. Physical disconnection only.
• Step 2 — Verify replacement unit: Before mounting, measure output voltage under no-load. Acceptable range: 23.8–24.4 VDC. A unit outside this range should not be installed regardless of its origin.
• Step 3 — Inspect DIN rail clip: A worn or cracked DIN clip on a vibrating machine creates intermittent contact faults that perfectly mimic power supply failure. Replace the clip if there is any play in the mount.
• Step 4 — No configuration required: The INR-244-755 has no DIP switches, no address settings, no firmware. It is a passive regulated supply. Slot in, connect terminals, power up.
• Step 5 — Allow fieldbus re-establishment: After power-up, wait 10–15 seconds for the EX coupler to re-initialize and re-establish fieldbus communication. Some PROFIBUS DP masters require a manual bus reset or a GSD re-scan before the node reappears.
• Step 6 — Load test: Energize all solenoids simultaneously and monitor supply output voltage under full load. If voltage sags below 23.5 VDC or the island resets, suspect a downstream short on the solenoid rail — measure current draw before condemning the new supply.

EX Series Fault Code Reference:

• Error 70 / PWR Fault — Output voltage out of acceptable range. Confirm INR-244-755 output is within 23.8–24.4 VDC under load.
• Fieldbus communication timeout (PLC master) — Power loss to coupler is the primary cause. Replace INR-244-755 before investigating fieldbus cable or termination resistors.
• Partial output loss (subset of valves inactive) — This fault pattern does not originate from the INR-244-755. Investigate individual solenoid driver circuits or the manifold wiring harness.

Reliability in Harsh Conditions

The INR-244-755 is not a general-purpose DIN rail supply repurposed for automation. It is engineered specifically for the electrical environment inside SMC EX manifold islands — a load profile characterized by high-frequency switching transients from solenoid coils, inrush spikes on simultaneous energization, and the thermal cycling that comes with production schedules that run 24 hours and then go cold overnight.

The PCB assembly uses conformal coating as standard, not as an option. This matters in food processing facilities, coastal plants, and chemical environments where humidity levels inside cabinets regularly exceed what uncoated boards can tolerate. The coating also protects against the conductive dust contamination that is endemic in metalworking and woodworking applications.

Vibration resistance is built into the mechanical design. Terminal blocks are screw-clamped with thread-locking compound applied at the factory. The DIN rail clip uses a positive-locking mechanism with a defined extraction force — it does not rattle loose on press lines or mobile equipment. Internal components are selected for vibration tolerance, not just thermal rating.

The wide-input switching topology (100–240 VAC) means the supply handles the voltage sags and brownouts common in heavy industrial environments without dropout. In facilities where the local grid is unstable during peak production hours, this input tolerance is the difference between a stable manifold island and one that resets every time a large motor starts nearby.

Every unit we dispatch is physically inspected: terminal block condition, DIN clip spring tension, output voltage measurement, and visual inspection for any evidence of prior installation or repair. We do not ship units that have been opened, repinned, or show field wear. If a unit does not pass our bench check, it does not leave the warehouse.

Global Express Logistics

Our warehouse is in Xiamen, Fujian — a primary export hub with direct daily flights to major international cargo hubs and established accounts with DHL Express, FedEx International Priority, and UPS Worldwide Express. Stock is physically on our shelves. This is not a marketplace listing that routes through a third-party fulfillment center.

Estimated Transit Times from Xiamen (business days):

• Southeast Asia (Singapore, Thailand, Malaysia, Vietnam, Indonesia): 2–3 days via DHL Express
• East Asia (Japan, South Korea, Taiwan): 2–3 days via FedEx International Priority
• Europe (Germany, Netherlands, UK, France, Italy, Spain): 3–5 days via FedEx or DHL
• North America (USA, Canada): 3–5 days via DHL Express or FedEx
• Middle East (UAE, Saudi Arabia, Qatar, Kuwait): 3–4 days via DHL
• Australia / New Zealand: 3–4 days via FedEx
• South America (Brazil, Chile, Colombia, Argentina): 5–7 days; local customs clearance times vary by country

Every shipment includes a commercial invoice, packing list, and certificate of origin as standard. For customers requiring HS code documentation, formal customs declarations for industrial components, or specific country-of-origin certification formats, we prepare these before dispatch — not as an aftercharge. We have cleared industrial automation parts through customs in over 40 countries and understand what documentation each region’s authorities require to avoid holds.

For plant-down situations where every hour has a cost attached to it — contact us directly on WhatsApp. We will confirm stock, process the order, coordinate same-day dispatch, and send you the airway bill number within hours so your team can track the shipment in real time and prepare for receipt.

Contact Information

📧 Email: [email protected]
💬 WhatsApp: +86 18359268345
🌐 Web: siemensplc.com
© 2026 siemensplc.com. All rights reserved.