NI SCXI-1326

Electrical Parameters

• Total Independent Screw Terminals: 48 screw terminals, divided evenly into 8 isolated wiring banks (6 terminals per bank)
• Per-Bank Terminal Layout: Each bank includes 1 VCC power terminal, 1 GND ground terminal, 4 channel signal load terminals
• Maximum Rated Working Voltage: 250 V RMS (Installation Category II per IEC 664 standard)
• Inter-Bank Isolation Rating: 250 V RMS isolation voltage between separate wiring banks and between each bank and chassis earth ground
• Supported Wiring Wire Gauge: 14–26 AWG insulated copper signal/load wire, wire insulation minimum rating 300 V, operating temperature 60°C
• Screw Terminal Tightening Torque Standard: 5–7 inch-pounds

Environmental & Physical

• Operating Temperature: 0°C ~ 50°C
• Storage Temperature: -20°C ~ 70°C
• Relative Humidity: 10% ~ 90% non-condensing
• Installation Standard: Supports DIN EN 50022 / DIN EN 50035 DIN rail auxiliary mounting and direct front-panel mating with SCXI relay modules

Functional Features

1. Eight Electrically Isolated Wiring Banks: The 48 terminals are split into eight fully separated banks with high-voltage isolation barriers between each bank; users can connect mixed AC and DC load circuits to different banks without cross-bank short-circuit or voltage crosstalk risks.
2. Dedicated Power & Ground Terminals Per Bank: Every wiring bank is equipped with independent VCC power supply terminal and GND ground terminal, eliminating shared power/ground wiring interference between different load circuits connected to separate banks.
3. High-Voltage Safety Design (Cat II 250 V RMS Rated): All terminal hardware, plastic base and internal isolation barriers are rated for 250 V RMS industrial high-voltage load wiring, fully matching the maximum 240 V AC/DC switching capacity of the SCXI-1163R solid-state relay module.
4. Integrated Full Electromagnetic Shielding Enclosure: The terminal block outer housing includes a built-in metal shielding layer to suppress external cabinet EMI interference that may induce false relay trigger signals in digital load wiring.
5. Hinged Safety Protective Cover: Transparent flame-retardant plastic hinged cover fully encloses all live high-voltage screw terminals after wiring completion, preventing accidental human contact with live high-voltage terminals and conductive foreign matter short-circuit hazards.
6. Direct Plug-And-Mate SCXI Relay Module Interface: Rear molded mating connector precisely aligns with the front I/O connector of SCXI digital relay modules (SCXI-1163R); two locking thumbscrews secure the terminal block firmly to the module front panel without specialized assembly tools.

Working Principle

Material & Structural Characteristics

1. Terminal Block Base Housing: UL94-V0 flame-retardant reinforced polycarbonate plastic base with integrated internal high-voltage isolation partitions between each wiring bank; built-in thin metal EMI shielding sheet fully lining the inner housing cavity.
2. Screw Terminal Hardware: Thick tin-plated brass terminal clamping bodies and wire jaws, rated for continuous high-voltage AC/DC load current transmission, anti-oxidation and corrosion-resistant for industrial cabinet environments; steel flat-head tightening screws with standardized torque limits.
3. Safety Protective Cover: Transparent flame-retardant polycarbonate hinged cover with integrated locking tabs to prevent accidental opening after installation.
4. Rear Mating Connector Assembly: Molded high-temperature plastic connector housing with gold-plated copper contact pins for stable low-resistance electrical connection with SCXI relay module front I/O connectors; two metal thumbscrews for front-panel locking.
5. Auxiliary DIN Rail Mounting Bracket: Removable metal DIN rail adapter bracket for independent DIN rail cabinet mounting when not directly mated to an SCXI relay module.

Installation Requirements

1. Module Compatibility Limitation: Exclusively designed for NI SCXI isolated digital relay modules (SCXI-1162, SCXI-1162HV, SCXI-1163, SCXI-1163R); incompatible with analog input or RF multiplexer SCXI modules.
2. High-Voltage Wire Specification Mandate: All load signal wires connected to the terminal block must have insulation rated minimum 300 V Cat II, wire operating temperature rating ≥60°C; wire gauge limited to 14–26 AWG solid/stranded copper wire.
3. Per-Bank Independent Power Wiring Rule: Do not share VCC or GND wiring between separate wiring banks; each bank’s load power supply and ground return must connect exclusively to that bank’s dedicated VCC and GND terminals to eliminate cross-bank electrical interference.
4. Mating Locking Procedure: Align the rear connector of SCXI-1326 with the front I/O connector of SCXI-1163R, fully insert the mating connector, then manually tighten the top and bottom thumbscrews to lock the terminal block securely to the module front panel.
5. Grounding Safety Specification: Connect the terminal block chassis ground lug to the control cabinet protective earth ground bar using a minimum 1.5 mm² copper ground wire to provide a low-impedance fault current discharge path for high-voltage load circuit short-circuit events.
6. Post-Wiring Safety Inspection: After completing all load wiring and tightening terminal screws to specified torque, close the transparent protective cover and fasten the cover locking tabs to isolate all live high-voltage screw terminals.

Application Scenarios

1. Industrial automation solenoid valve, indicator light, small motor high-voltage load wiring terminal, paired with SCXI-1163R relay switch modules.
2. Power system test bench high-voltage relay switching load wiring interface.
3. Building automation HVAC actuator, lighting zone control high-voltage wiring terminal accessory.
4. Laboratory automated test equipment AC/DC load bank multi-channel switching wiring terminal block.
5. Energy equipment auxiliary safety relay control circuit high-voltage isolated wiring terminal.

Operation & Usage Precautions

1. High-Voltage Electric Shock Hazard Warning: All load wiring installation, modification or disconnection must be performed after fully cutting off both the SCXI chassis control power supply and all field load power supply; live high-voltage terminal contact creates severe electric shock hazards to operators.
2. Screw Terminal Torque Control: Tighten terminal screws strictly within the 5–7 in-lb torque range; over-tightening cracks the plastic isolation partitions between wiring banks and deforms brass terminal jaws; under-tightening causes loose load wiring, leading to intermittent circuit open faults and terminal overheating under continuous load current.
3. Cross-Bank Voltage Mixing Restriction: Avoid connecting load circuits with drastically different voltage levels (e.g., 24 V DC low-voltage control circuits and 220 V AC high-voltage actuator circuits) to adjacent wiring banks without adequate insulation separation; voltage leakage across isolation barriers may induce stray voltage faults in low-voltage circuits.
4. No Unauthorized Modification Prohibition: Do not drill, cut or modify the terminal block plastic base, internal isolation partitions or built-in metal shielding layer; structural modification destroys high-voltage isolation and EMI shielding performance, creating permanent safety hazards.
5. Cleaning Maintenance Restrictions: Only clean dust and debris from the terminal block using dry non-metallic anti-static brushes; never use water, liquid solvents or conductive cleaning sprays to wipe high-voltage screw terminals, which will cause terminal oxidation and electrical short-circuit failure under high-voltage load conditions.
6. Overvoltage Protection Limit: Do not connect load circuits with working voltage exceeding 250 V RMS to any terminal bank; overvoltage will break down the internal isolation barriers between wiring banks, causing permanent terminal block damage and catastrophic cross-circuit short-circuit faults.