{"product_id":"1756-oa16i-allen-bradley-1756-controllogix-isolated-ac-digital-output-module","title":"1756-OA16I Allen-Bradley 1756 ControlLogix Isolated AC Digital Output Module","description":"\u003ch3\u003e\u003cstrong\u003e1756-OA16I Allen-Bradley ControlLogix Isolated AC Output Module\u003c\/strong\u003e\u003c\/h3\u003e\n\n\u003cp\u003eThe Allen-Bradley 1756-OA16I is a 16-point discrete AC output module in the ControlLogix 1756 family. It switches external AC loads through individually isolated output points and supports nominal 120 VAC and 240 VAC applications. The specified operating input-to-load voltage range is 74–265 VAC at 47–63 Hz.\u003c\/p\u003e\n\n\u003cp\u003eFor control engineers, the important selection criteria are not limited to channel count. The 1756-OA16I has both per-point and aggregate current limits, temperature-dependent derating, off-state leakage current, and configurable output behavior during program mode and fault conditions. These factors determine whether the module is suitable for contactors, solenoid valves, pilot devices and other AC loads in an existing ControlLogix installation.\u003c\/p\u003e\n\n\u003ch3\u003e\u003cstrong\u003e01 | Product at a Glance\u003c\/strong\u003e\u003c\/h3\u003e\n\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eManufacturer:\u003c\/strong\u003e Rockwell Automation\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eBrand:\u003c\/strong\u003e Allen-Bradley\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eProduct family:\u003c\/strong\u003e ControlLogix 1756\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCatalog number:\u003c\/strong\u003e 1756-OA16I\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eModule type:\u003c\/strong\u003e Isolated AC digital output module\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eNumber of outputs:\u003c\/strong\u003e 16 individually isolated points\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eNominal output voltage:\u003c\/strong\u003e 120\/240 VAC\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOperating voltage range:\u003c\/strong\u003e 74–265 VAC\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOperating frequency:\u003c\/strong\u003e 47–63 Hz\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eChassis occupancy:\u003c\/strong\u003e Single slot\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eConnection method:\u003c\/strong\u003e Removable terminal block (RTB)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCompatible RTBs listed in the supplied data:\u003c\/strong\u003e 1756-TBCH and 1756-TBS6H\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003e\u003cstrong\u003eProcurement note:\u003c\/strong\u003e The RTB is a separate compatibility consideration. Confirm whether the required terminal block is included with the offered module and whether the installed wiring assembly is suitable for the replacement.\u003c\/p\u003e\n\n\u003ch3\u003e\u003cstrong\u003e02 | Output Loading: The Limits Engineers Must Check\u003c\/strong\u003e\u003c\/h3\u003e\n\n\u003cp\u003eThe module has separate limits for individual output points and total module current. Meeting the limit on each point does not automatically mean that all 16 outputs can operate at their individual maximum currents simultaneously.\u003c\/p\u003e\n\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eContinuous current per point at 30 °C:\u003c\/strong\u003e 2 A, with linear derating specified.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eContinuous current per point at 60 °C:\u003c\/strong\u003e 1 A, with linear derating specified.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMaximum aggregate module current at 30 °C:\u003c\/strong\u003e 5 A, with linear derating specified.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMaximum aggregate module current at 60 °C:\u003c\/strong\u003e 4 A, with linear derating specified.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMaximum power dissipation:\u003c\/strong\u003e 5.5 W at 60 °C.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eThermal dissipation:\u003c\/strong\u003e 18.76 BTU\/hr, as listed in the supplied specifications.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003e\u003cstrong\u003ePractical example:\u003c\/strong\u003e If several contactors are energized at the same time, calculate their steady-state current and consider the simultaneous operating pattern. Also account for coil inrush, cabinet temperature and the module's aggregate current limit. A design that satisfies the 2 A per-point rating can still exceed the total module rating.\u003c\/p\u003e\n\n\u003cp\u003eFor inductive loads, check the load manufacturer's switching requirements and the applicable Rockwell Automation installation guidance. Do not select a module solely from a contactor's nominal coil voltage.\u003c\/p\u003e\n\n\u003ch3\u003e\u003cstrong\u003e03 | Switching Characteristics and Electrical Behavior\u003c\/strong\u003e\u003c\/h3\u003e\n\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eOFF-to-ON delay:\u003c\/strong\u003e 9.3 ms at 60 Hz; 11 ms at 50 Hz.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eON-to-OFF delay:\u003c\/strong\u003e 9.3 ms at 60 Hz; 11 ms at 50 Hz.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOFF-state leakage current:\u003c\/strong\u003e 3 mA per point.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eON-state voltage drop:\u003c\/strong\u003e Up to 1.5 V at 2 A; the supplied data lists 6 V at a load current below 50 mA.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMinimum load current:\u003c\/strong\u003e 10 mA per point, as listed in the supplied specifications.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eInrush current:\u003c\/strong\u003e 20 A for 43 ms per point, repeatable every 2 seconds at 60 °C, according to the supplied data.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eOff-state leakage deserves particular attention when driving low-current loads. A device that receives a small current while the output is logically OFF may glow faintly, remain partially energized or fail to release as expected. Check the load's minimum operating current and leakage tolerance before connecting sensitive electronic loads.\u003c\/p\u003e\n\n\u003cp\u003eFor relay coils, solenoids and contactors, evaluate switching frequency, inrush current and the required suppression method. Confirm that any external suppression component is suitable for the AC load and does not compromise the output's switching behavior.\u003c\/p\u003e\n\n\u003ch3\u003e\u003cstrong\u003e04 | Output Isolation and Fault-State Configuration\u003c\/strong\u003e\u003c\/h3\u003e\n\n\u003cp\u003eThe 1756-OA16I provides individually isolated output points. This arrangement can help separate output circuits, but isolation does not eliminate the need for correct field wiring, branch protection and electrical safety procedures.\u003c\/p\u003e\n\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eOutput behavior during a controller fault:\u003c\/strong\u003e The supplied information lists configurable per-point states of Hold Last State, ON or OFF, with OFF as the default.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOutput behavior during program mode:\u003c\/strong\u003e Hold Last State, ON or OFF are listed as configurable choices, with OFF as the default.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eInternal fusing:\u003c\/strong\u003e The supplied description states that the module has no internal fusing.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eIsolation rating:\u003c\/strong\u003e The supplied material includes conflicting descriptions of the isolation voltage. Confirm the applicable manufacturer's specification for output-to-output and output-to-backplane isolation before using the module in a safety or insulation design.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eChoose output fault states according to the machine's risk assessment and process requirements. An OFF command is not a substitute for an independent safety function where hazardous motion, stored energy or process hazards must be controlled.\u003c\/p\u003e\n\n\u003ch3\u003e\u003cstrong\u003e05 | Backplane, Chassis and Connection Requirements\u003c\/strong\u003e\u003c\/h3\u003e\n\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eProduct family:\u003c\/strong\u003e ControlLogix 1756 chassis-based I\/O.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMounting:\u003c\/strong\u003e One chassis slot.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eChassis models listed in the supplied material:\u003c\/strong\u003e 1756-A4, 1756-A7, 1756-A10, 1756-A13 and 1756-A17.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eInstallation locations:\u003c\/strong\u003e A local rack or a compatible remote I\/O rack connected through a suitable 1756 communication adapter.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eRTB options listed:\u003c\/strong\u003e 1756-TBCH and 1756-TBS6H.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eEnclosure style:\u003c\/strong\u003e Open-style module; the installation must provide the required enclosure and environmental protection.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOperating temperature:\u003c\/strong\u003e 0 to 60 °C, as supplied.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eHumidity:\u003c\/strong\u003e 5–95% non-condensing.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMaximum operational shock:\u003c\/strong\u003e 30 G, as listed in the supplied data.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003e\u003cstrong\u003eBackplane-current discrepancy:\u003c\/strong\u003e The supplied specifications list 225 mA and 300 mA at approximately 5 V, and 2.5 mA and 3 mA at 24 V. These values conflict and should not be combined or treated as verified. Check the official module manual and the chassis power budget before finalizing a replacement or rack design.\u003c\/p\u003e\n\n\u003cp\u003eThe supplied material also lists an output signal schedule time of “16.7s.” Because the unit and meaning are unclear, this value is intentionally excluded from the verified operating characteristics. Confirm it from the applicable technical documentation before using it in a timing calculation.\u003c\/p\u003e\n\n\u003ch3\u003e\u003cstrong\u003e06 | Suitable Equipment and Industrial Applications\u003c\/strong\u003e\u003c\/h3\u003e\n\n\u003cp\u003eThe 1756-OA16I is intended for compatible ControlLogix systems that need to switch AC-powered field devices. Typical applications include:\u003c\/p\u003e\n\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eMotor control panels:\u003c\/strong\u003e Switching AC control circuits for contactors and motor starter interfaces, subject to load and protection requirements.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eProcess skids:\u003c\/strong\u003e Controlling AC solenoid valves, actuators and auxiliary devices.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePackaging and assembly equipment:\u003c\/strong\u003e Operating AC pilot devices and machine-control loads.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWater and wastewater plants:\u003c\/strong\u003e Switching compatible AC control loads in pumping and treatment systems.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eHVAC and utility systems:\u003c\/strong\u003e Operating selected AC relays, contactors and auxiliary equipment.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eIndustrial furnaces and thermal equipment:\u003c\/strong\u003e Switching suitable AC control loads, provided the load current and control design meet the module's limits.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eControlLogix maintenance and retrofit projects:\u003c\/strong\u003e Replacing a failed output module while retaining a compatible chassis and field-wiring arrangement.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eThese are examples of potential applications, not a blanket approval for every device. Verify load voltage, steady-state current, inrush current, switching frequency, leakage tolerance and any required external protection before connecting a field load.\u003c\/p\u003e\n\n\u003ch3\u003e\u003cstrong\u003e07 | Field Diagnostics: Symptom-Based Checks\u003c\/strong\u003e\u003c\/h3\u003e\n\n\u003cp\u003e\u003cstrong\u003eSymptom: A field device does not energize\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cul\u003e\n\u003cli\u003eConfirm the controller is in the intended operating mode and the output command is being issued.\u003c\/li\u003e\n\u003cli\u003eCheck the AC supply voltage and frequency at the field circuit.\u003c\/li\u003e\n\u003cli\u003eInspect the terminal-block seating, field wiring, protective devices and load continuity.\u003c\/li\u003e\n\u003cli\u003eCompare the commanded output state with the module's indicated state and available controller diagnostics.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003e\u003cstrong\u003eSymptom: The load remains energized when the output is OFF\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cul\u003e\n\u003cli\u003eMeasure the voltage across the load and account for the specified off-state leakage current.\u003c\/li\u003e\n\u003cli\u003eCheck whether the load has a low input-current requirement or high sensitivity to leakage.\u003c\/li\u003e\n\u003cli\u003eInspect for wiring cross-connections or an unintended alternate supply path.\u003c\/li\u003e\n\u003cli\u003eDo not assume a logically OFF output provides galvanic disconnection from the AC supply.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003e\u003cstrong\u003eSymptom: The module or field circuit trips under simultaneous operation\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cul\u003e\n\u003cli\u003eMeasure the current of individual loads and calculate the aggregate current.\u003c\/li\u003e\n\u003cli\u003eCheck both the per-point limit and the total module limit at the actual cabinet temperature.\u003c\/li\u003e\n\u003cli\u003eReview coil inrush, load switching frequency, branch protection and external suppression.\u003c\/li\u003e\n\u003cli\u003eDetermine whether the problem follows a particular load or occurs only when multiple outputs are active.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003e\u003cstrong\u003eSymptom: Output behavior changes after a controller fault or mode change\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cul\u003e\n\u003cli\u003eReview the configured fault state and program-mode state for the affected output points.\u003c\/li\u003e\n\u003cli\u003eConfirm whether Hold Last State, ON or OFF is configured.\u003c\/li\u003e\n\u003cli\u003eCheck controller status and event history before replacing the module.\u003c\/li\u003e\n\u003cli\u003eValidate the expected restart sequence and ensure that field devices return to a safe operating condition.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003e\u003cstrong\u003eSymptom: A replacement module does not operate as expected\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cul\u003e\n\u003cli\u003eVerify the exact catalog number and the module's physical condition.\u003c\/li\u003e\n\u003cli\u003eConfirm the chassis, terminal block and wiring arrangement are compatible.\u003c\/li\u003e\n\u003cli\u003eCheck the project configuration and output addressing against the installed hardware.\u003c\/li\u003e\n\u003cli\u003eReview the fault-state settings and confirm that the field supply is within the specified AC range.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eAlways isolate and verify the absence of hazardous voltage before touching field wiring. AC output circuits can remain energized independently of the controller's logic state.\u003c\/p\u003e\n\n\u003ch3\u003e\u003cstrong\u003e08 | Global PLC Spare HUB's Insight\u003c\/strong\u003e\u003c\/h3\u003e\n\n\u003cp\u003eFor the 1756-OA16I, output-current calculations and field-load behavior are often more useful than the channel count alone when planning a replacement. The 16 isolated points provide flexibility for multiple AC circuits, but the aggregate current limit means that the total load must be assessed alongside the current on each individual point.\u003c\/p\u003e\n\n\u003cp\u003eIn troubleshooting, separate a control-logic problem from a field-power problem. If the output command changes correctly but the load does not respond, inspect the AC supply, RTB connections, load continuity and protection devices before concluding that the output electronics have failed. If the load remains partially energized with the output OFF, investigate leakage current and the load's minimum operating current.\u003c\/p\u003e\n\n\u003cp\u003eBefore ordering a spare, provide the full catalog number, a label photo, the existing terminal-block model and the type of AC loads being controlled. For critical equipment, also record the controller fault-state requirements and the cabinet operating temperature. This information helps establish whether the replacement is appropriate for the installed application.\u003c\/p\u003e\n\n\u003ch3\u003e\u003cstrong\u003e09 | Warranty and Shipping\u003c\/strong\u003e\u003c\/h3\u003e\n\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eWarranty:\u003c\/strong\u003e 12 months, subject to the agreed sales terms.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePre-shipment checks:\u003c\/strong\u003e Model identification and condition checks, as applicable to the supplied unit.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCourier options:\u003c\/strong\u003e FedEx, UPS and DHL, subject to destination and service availability.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eQuotation:\u003c\/strong\u003e Contact Global PLC Spare HUB with the quantity, delivery destination and compatibility details to request pricing and lead-time information.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003e\u003cstrong\u003e10 | Frequently Asked Questions\u003c\/strong\u003e\u003c\/h3\u003e\n\n\u003cp\u003e\u003cstrong\u003eQ1: Can the 1756-OA16I switch a 240 VAC load if the nominal voltage is listed as 120\/240 VAC?\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eThe supplied operating range is 74–265 VAC at 47–63 Hz, which includes nominal 240 VAC. Confirm the actual load current, inrush characteristics, circuit protection and the manufacturer's installation requirements before connecting the device. The voltage range alone does not establish that every 240 VAC load is suitable.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eQ2: How do I determine whether the module's total current rating is sufficient for my machine?\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eList the steady-state current of each connected load, identify which loads can operate simultaneously and calculate the aggregate demand. Check the current limit for every point as well as the module-wide limit. Repeat the assessment at the expected cabinet temperature because the supplied current ratings are lower at 60 °C than at 30 °C.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eQ3: Is the 1756-OA16I suitable for directly driving a small electronic input that draws very little current?\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eDo not decide from the voltage rating alone. The supplied data lists 3 mA of off-state leakage per point and a minimum sustained load current of 10 mA. Compare these values with the connected device's input specifications. For a sensitive or low-current load, verify compatibility with the manufacturer's documentation and consider an appropriate interface device if required.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eQ4: What should I check before transferring the existing terminal block to a replacement module?\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eConfirm the terminal block model, wiring condition, terminal integrity and compatibility with the replacement. Record wire labels and verify each circuit against the electrical drawings before disconnecting anything. Follow site lockout procedures and verify that hazardous AC voltage is absent before handling the RTB or field conductors.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eQ5: What information helps avoid ordering the wrong ControlLogix output module?\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eProvide the complete catalog number, a photo of the installed label, the chassis and RTB details, the field voltage, the connected load types and the required fault-state behavior. If the module is part of a legacy installation, include the controller and project configuration details where available. Similar-looking output modules may differ in isolation, load type, current limits and wiring requirements, so verify the exact model rather than selecting by appearance alone.\u003c\/p\u003e","brand":"Allen-Bradley","offers":[{"title":"Default Title","offer_id":45013809627318,"sku":"1756-OA16I","price":149.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0722\/7863\/8774\/files\/1756-OA16I.jpg?v=1792475771","url":"https:\/\/www.plcsparehub.com\/products\/1756-oa16i-allen-bradley-1756-controllogix-isolated-ac-digital-output-module","provider":"Global PLC Spare Hub","version":"1.0","type":"link"}