Description
Product Introduction
The Allen-Bradley 1746-A10 is a 10-slot modular chassis designed for the SLC 500 programmable logic controller family. Serving as the primary physical frame and backplane communication bus, it holds the main SLC 500 CPU (such as a 1747-L542 or 1747-L551) in Slot 0 alongside up to 9 digital, analog, or specialty I/O cards in remaining slots.
Featuring an integrated left-hand power supply mounting bay, the 1746-A10 receives clean DC power from a 1746 power supply (e.g., 1746-P1, P2, or P4) and distributes +5V DC and +24V DC across the backplane to all connected modules. For larger control systems, multiple 1746 chassis can be daisy-chained using 1746-C9 or 1746-C13 interconnect cables to expand a single system up to 30 slots.
Key Technical Specifications
| Parameter | Specification |
| Manufacturer Part Number | 1746-A10 |
| Number of Slots | 10 Module Slots |
| Power Supply Compatibility | 1746-P1, 1746-P2, 1746-P3, 1746-P4, 1746-P7 |
| Backplane Current Capacity | 10 A at 5V DC / 2.88 A at 24V DC (Supply Limited) |
| Expansion Port | Right-hand side interconnect bus port for C-Series cables |
| Mounting Options | Backpanel Screw Mount (EN 50022 compliant) |
| Dimensions (W x H x D) | 438.4 mm x 171.5 mm x 146.0 mm (17.26 in x 6.75 in x 5.75 in) |
| Operating Temperature | 0°C to 60°C (32°F to 140°F) |
| Vibration & Shock Rating | 2.5 g at 57-200 Hz / 30 g operational shock |
Application Scenarios & The “Trench” Experience
It is 3:00 AM on an industrial water filtration facility shift. A sudden high-voltage transient on an ungrounded 24V field supply causes an arc flash across a relay module, scorching the backplane connector in Slot 4 of a critical 1746-A10 rack. The CPU loses communication with all downstream I/O modules. The shift technician isolates power, unplugs the 1746-P2 power supply and 9 I/O cards, swaps in a pre-tested 1746-A10 chassis from plant spares, restores the cards and DIP switches, and returns the entire plant’s backwash sequence to auto in under 20 minutes.
- Legacy Plant Upgrades & Drop-In Replacement – SLC 5/03, 5/04, 5/05 Racks – Main rack housing for medium-to-large legacy PLC panels.
- Multi-Chassis Expansion Systems – Distributed Machine I/O – Serves as Local Rack 1 or Expansion Rack 2 via 1746-C13 interconnect cables.
- High-Density Discrete & Analog Panels – Stamping & Processing Lines – Holds high-density 16 and 32-point 1746 I/O modules in a consolidated cabinet footprint.
Transparency SOP: Quality Assurance & Testing
We don’t just ship boxes; every chassis is rigorously inspected and backplane-tested on active SLC 500 test racks.
- Inbound Mechanical & Socket Audit: Checked all 10 card slot backplane edge-connectors for bent, corroded, or spread terminal contacts.
- Backplane Continuity & Trace Testing: Point-to-point resistance verified on all parallel address, data, and power distribution rails.
- Live Power & CPU Scan Test: Installed a 1746-P2 power supply and 1747-L552 processor; verified full I/O card address mapping and fault-free backplane scanning across all 10 slots.
- Interconnect Bus Port Check: Connected a 1746-C9 expansion cable to verify signal integrity through the right-side expansion header.
- ESD Protection & Packaging: Cleaned, wrapped in heavy static-shielding material, and packaged inside shock-absorbing foam crates.
- 1746-A10
- 1746-A10
The Veteran’s Tech Trap Guide (Crucial Value-Add)
- ⚠️ Calculate Your Backplane Power Budget (5V vs. 24V)!
A common mistake when populating all 10 slots of a 1746-A10 is exceeding the 5V DC backplane current rating of the power supply (e.g., 1746-P1 provides 2.0A at 5V, while 1746-P2 provides 5.0A). Overloading the 5V bus causes intermittent
Major CPU Faults (Code 0020 - Rack Communication Loss). Always tally the 5V and 24V consumption of all 10 cards using the SLC 500 power selection table. - ❗ Never Hot-Swap Modules in a 1746 Chassis!
The SLC 500 platform (1746 series) does NOT support Insertion and Removal Under Power (RIUP). Removing or inserting an I/O card while 120/230V main power is applied to the 1746 power supply can ruin the processor backplane driver ICs or corrupt the CPU memory.
- ⚠️ Handle Expansion Cable DIP Switches Carefully
If using the 1746-A10 as an expansion chassis connected via a 1746-C9 or 1746-C13 cable, ensure the maximum total cable length across the entire SLC system does not exceed 30 feet (9.1 meters) to prevent high-frequency timing delays on the backplane data bus.
- ❗ Firmly Lock Top & Bottom Module Retaining Clips
Verify that the spring-loaded plastic locking tabs at the top and bottom of each 1746 module snap securely into the chassis frame. Loose module seating leads to intermittent backplane pin disconnects caused by machine vibration.
Frequently Asked Questions (FAQ for Conversion)
Q: What is the difference between 1746-A10, 1746-A7, and 1746-A13?
A: The difference is the total number of module slots available in the rack: 1746-A4 (4 slots), 1746-A7 (7 slots), 1746-A10 (10 slots), and 1746-A13 (13 slots).
Q: Does the 1746-A10 come with a power supply included?
A: No. The 1746-A10 is the bare chassis/backplane assembly. The power supply (such as 1746-P1, P2, P3, or P4) must be purchased separately and mounted into the dedicated left-hand bay.
Q: Can I mount an SLC 5/05 Ethernet processor in any slot of the 1746-A10?
A: No. In all 1746 modular chassis, the main processor (SLC 5/01, 5/02, 5/03, 5/04, or 5/05) must always be installed in Slot 0 (the slot immediately to the right of the power supply).
Q: Are 1746-A10 racks still manufactured by Allen-Bradley?
A: The SLC 500 system has matured into legacy/discontinued status by Rockwell Automation. We maintain extensive inventory of high-grade New Surplus and fully bench-tested, certified refurbished original 1746-A10 chassis.
Q: What warranty is provided with this 10-slot rack?
A: Every Allen-Bradley 1746-A10 chassis includes a full 12-month replacement warranty. If any slot or backplane trace experiences failure under standard operating conditions within one year, we ship an immediate replacement directly from stock.
Start Chat
