Description
Product Introduction
The Allen-Bradley 1746-IM16 is a high-density, 16-point 200/240V AC digital input module designed for the SLC 500 programmable logic controller system. Installed into any standard slot of a 1746 chassis (such as a 1746-A7, 1746-A10, or 1746-A13 rack), the module provides interface connections between high-voltage 230V AC field control loops and the low-voltage logic backplane of the SLC processor.
eaturing optical isolation between field wiring and internal backplane circuitry, the 1746-IM16 protects the CPU from severe electrical noise, voltage spikes, and ground loops common in European and heavy 230V industrial power grids. Its 16-point high-density layout with a front-facing LED status indicator array allows maximum I/O capacity within a single chassis slot.
Key Technical Specifications
| Parameter | Specification |
|---|---|
| Manufacturer Part Number | 1746-IM16 |
| Number of Inputs | 16 Digital AC Inputs |
| Voltage Category | 200/240V AC |
| Operating Voltage Range | 170 to 265V AC at 47–63 Hz |
| Off-State Voltage (Max) | 50V AC |
| On-State Current (Min) | 5.0 mA at 170V AC |
| Nominal Input Current | 12 mA at 240V AC |
| Backplane Current Draw | 85 mA at 5V DC / 0 mA at 24V DC |
| Signal Delay (Max) | Turn-On = 35 ms, Turn-Off = 45 ms |
| Points per Common | 16 Points on 1 Common |
| Operating Temperature | 0°C to 60°C (32°F to 140°F) |
Application Scenarios & The “Trench” Experience
It is 10:00 PM in a European chemical processing plant operating on 230V control logic. A batch reactor stirrer panel loses run feedback on Input Bit 11, causing a safety interlocking trip. The maintenance electrician suspects an internal optocoupler failure on a channel of an aging 1746-IM16 card. Utilizing the 1746 removable terminal block (RTB), the electrician isolates panel power, unclips the fully wired terminal arm without loosening any field screws, replaces the card with a bench-tested 1746-IM16 from local spares, reattaches the RTB, and powers up—returning the reactor process to service in under 10 minutes.
- Heavy Machinery & 230V Control Systems – Motor Contactor Aux Contacts – Monitors 230V AC auxiliary feedback signals on large industrial motor starters.
- Overseas & International Equipment Retrofits – 220–240V Machine Skids – Reads high-voltage selector switches, limit switches, and safety relays in plants utilizing 220V/240V control transformer secondary circuits.
- High-Density Rack Upgrades – SLC 5/03, 5/04, 5/05 Systems – Replaces lower-density 8-point modules (like 1746-IM8) to double I/O capacity without expanding physical rack size.
- 1746-IM16
- 1746-
Transparency SOP: Quality Assurance & Testing
We don’t just ship boxes; every 1746- module undergoes thorough diagnostic bench testing prior to dispatch.
- Inbound Physical & Terminal Audit: Checked housing plastics, backplane edge connector pins, and terminal block screw threads for signs of physical stress, arcing, or corrosion.
- Backplane Logic Verification: Installed into an active 1746-A10 rack; verified 85 mA backplane power consumption and proper CPU card detection without backplane faults.
- 16-Channel Voltage Threshold Testing: Applied 230V AC input signals across each of the 16 channels individually; confirmed LED status illumination and RSLogix 500 input data table updating (
I:e.0throughI:e.15). - Off-State Threshold & Leakage Test: Verified that voltages below 50V AC properly register as OFF to ensure immunity against stray line noise or cable capacitance.
- ESD Protection & Packaging: Cleaned, wrapped in antistatic shielding wrap, and packaged inside shock-absorbing foam containers.
The Veteran’s Tech Trap Guide (Crucial Value-Add)
- ⚠️ Do NOT Mix Up 120V (IA16) and 240V () Cards! The 1746- is strictly designed for 200/240V AC nominal voltage. Connecting 120V AC to this card will not damage it, but the input circuits will NOT turn ON (minimum ON voltage is 170V AC). If your panel uses 120V AC control power, you must use a 1746-IA8 or 1746-IA16 card instead.
- ❗ Never Hot-Swap Modules in a 1746 Chassis! Like all SLC 500 components, inserting or removing the 1746- while rack power is applied will cause electrical arcing across high-voltage backplane pins, potential CPU memory corruption, or permanent board damage. Always isolate main rack power prior to swapping modules.
- ⚠️ Mind the 35ms Input Filter Delay! The 1746- has a hardware input filtering delay of 35 ms (turn-on) and 45 ms (turn-off) to ignore AC sine wave zero-crossing noise. Do not use this module for high-speed pulse counting or rapid part sensing; use DC input modules or a counter card like the 1746-HSCE.
- ❗ Single Common Return Line All 16 input channels share a single common line (Terminal 17). Ensure the neutral/return leg of your 230V AC control transformer is securely landed on the common terminal to complete the input loop.
Frequently Asked Questions (FAQ for Conversion)
Q: What is the difference between 1746-IA16 and 1746-? A: The 1746-IA16 is designed for 100/120V AC systems (85–132V AC operating range), whereas the is designed for high-voltage 200/240V AC systems (170–265V AC operating range).
Q: What is the difference between 1746-IM8 and 1746-? A: The 1746-IM8 provides 8 digital 230V AC inputs, while the provides 16 digital 230V AC inputs within the same single-slot card footprint.
Q: Does the 1746- module come with the removable terminal block (RTB)? A: Yes, all our New Surplus and Refurbished 1746- modules include the front removable terminal block assembly.
Q: Are 1746- modules still manufactured by Allen-Bradley? A: The SLC 500 platform has matured into legacy/discontinued status by Rockwell Automation. We maintain extensive stock of certified New Surplus and fully bench-tested, refurbished original 1746- modules.
Q: What warranty is provided with this module? A: Every Allen-Bradley 1746- input module includes a full 12-month replacement warranty. If any input channel or backplane interface fails under standard operating conditions within one year, we send an immediate replacement from stock.
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