AB 1769-PA2​ 1769 Power Supply – AC Input Alternative to 1769-PB3/PB4 DC Supplies for 1769 Rack Builds

Technical Specifications

Main Features and Advantages

Universal AC input for global and retrofit flexibility: The 1769-PA2​ accepts 100–240VAC across the full 47–63 Hz range, meaning a single SKU works in North American 120V panels, European/Asian 230V panels, and even sites with slightly unstable mains down to 100VAC. For OEMs, this cuts spare-part SKU count in half versus stocking separate 120V and 230V supplies; for retrofits migrating older SLC 500 1746-P1/P2 AC-powered racks to CompactLogix 5370 with 1769 I/O, the 1769-PA2​ drops into the same panel space, lands on the same AC feeder, and requires minimal rewiring — a major time-saver when the rest of the panel modernization is already consuming budget.Generous backplane budget with 24V aux offset: The 5VDC @5A output easily covers a fully loaded 8-slot 1769 rack: even a dense build with a 1769-L33ER processor (~0.8A 5V), three 1769-IQ16 digital input modules (~0.1A 5V each), two 1769-OW16 relay output modules (~0.2A 5V + 0.1A 24V each), and a 1769-IF4XOF2 analog combo (~0.12A 5V + 0.16A 24V) totals under 2A on the 5V rail, leaving >60% headroom for reliability. The 1A 24VDC backplane output is a quiet hero: it can feed small panel loads like 1769 digital input sensor excitation or small analog transmitter loops, taking that load off the panel’s primary 24VDC supply — critical in panels where the main 24VDC is already strained by VFD controls, HMIs, and safety devices.Platform-specific design (avoid the 1768-PA2 mixup): Rockwell’s 1768 and 1769 platforms share the “PA2” model suffix, but the 1769-PA2​ is exclusively for 1769 Compact I/O backplanes — it cannot power 1768 L4x modules, and 1768-PA2 cannot power 1769 modules, with mechanical keying preventing accidental insertion but lazy procurement sometimes overrides that. For sustainment teams managing mixed L3x/L4x fleets, we always cross-confirm “1769-” prefix before shipping 1769-PA2​ orders to avoid line-down surprises. The 1769-PA2​ also carries forward compatibility to legacy MicroLogix 1500 expansion racks, making it a shared spare across two controller families in plants that haven’t fully retired their MicroLogix 1500 assets.Protection and sustainment fit: The 1769-PA2​ includes auto-recovering overload and short protection on both backplane outputs — if a 1769 module develops a backplane short, the PA2 trips, protects the rest of the rack, and resets once the fault is cleared, avoiding a full panel power cycle in most cases. As a Rockwell-designated FRU, failed units are swapped rather than repaired, so our testing prior to shipment focuses on load-hold (5A@5V, 1A@24V) and fault-recovery validation to ensure the 1769-PA2​ hits the rack ready to run. Even as Rockwell steers new designs toward 5069 Compact I/O on 5380/5480 controllers (with 5069-PA4 AC supply), the 1769-PA2​ remains the active AC-power SKU for the massive installed base of CompactLogix 5370 and MicroLogix 1500 racks, with Rockwell sustaining both the supply and the 1769 module ecosystem for the foreseeable future.

Application Field

The 1769-PA2​ is the default AC-power choice for any 1769 Compact I/O rack where tapping 120/240VAC mains is simpler than allocating additional 24VDC panel capacity. In CompactLogix 5370 L3x-based OEM machinery — entry-level packaging labelers, conveyor sortation cells, small batch mixer skids, water/wastewater satellite lift stations — the 1769-PA2​ typically occupies slot 0 of the local 1769 rack, with the 1769-L33ER or 1769-L36ERM processor in slot 1, followed by 6 slots of mixed digital/analog I/O (e.g., 1769-IQ16, 1769-OW16, 1769-IF4XOF2) all drawing from the PA2’s 5V/24V backplane. For these machines, the PA2’s global 100-240VAC input means the OEM ships one panel configuration to both NA and EU customers, cutting BOM complexity and spare holding costs.In legacy plant sustainment, the 1769-PA2​ is equally common in MicroLogix 1500 expansion racks: the MicroLogix 1500’s base unit has limited built-in I/O and 24VDC aux capacity, so adding a 1769 expansion rack powered by a 1769-PA2​ lets plants scale I/O for older OEM machines (e.g., legacy rotary indexers, small injection molders) without migrating the entire controller to CompactLogix — a lower-cost sustainment path that preserves validated MicroLogix 1500 ladder code. Retrofit projects replacing SLC 500 1746-P1/P2 AC-powered racks with CompactLogix 5370 + 1769 I/O almost always land on the 1769-PA2​ because the existing AC feeder is already sized, the panel cutout matches 1769 rack dimensions, and the RSLogix 500 → Studio 5000 analog/digital scaling migration is trivial for 1769 modules.The 1769-PA2​ also finds a niche in panel load-balancing scenarios: panels with a maxed primary 24VDC supply (e.g., a panel running 10 VFDs with 24V control loops, plus HMI, plus safety light curtain) can offload the 1769 rack’s 5V (~2A average) and 24V (~0.5A average) draw to the 1769-PA2​ AC input, bringing the primary 24VDC supply back into its 80% rated window and avoiding a costly 24VDC supply upgrade. It is not suited for remote I/O applications (1769 is local-only; remote uses 1734 Point I/O with 1734-EP24DC) or for 1768 L4x racks (use 1768-PA2 instead) — staying in its 1769 lane keeps the 1769-PA2​ reliable and cost-effective.

Related Products

• 1769-PB3​ – 24VDC-input lower-capacity sibling of the 1769-PA2, 5V@3A / 24V@0.5A, for panels with stable 24VDC supply and lighter 1769 rack loads (e.g., 4-slot racks)
• 1769-PB4​ – 24VDC-input same-capacity sibling of 1769-PA2, 5V@5A / 24V@1A, for panels with robust 24VDC availability where AC input is not preferred
• 1768-PA2​ – Incompatible AC power supply for discontinued CompactLogix L4x 1768 racks; do not substitute for 1769-PA2​ even though model names are similar
• 1769-L33ER​ – CompactLogix 5370 L3x processor, most common host for a 1769-PA2-powered 8-slot local 1769 rack, EtherNet/IP onboard, up to 8 local 1769 modules
• 1769-L36ERM​ – CompactLogix 5370 L3x with integrated motion, pairs with 1769-PA2​ in local rack for motion + digital/analog I/O loops
• 1769-IF4XOF2​ – 4AI+2AO 8-bit analog combo module, typical load on 1769-PA2​ racks, draws 120mA@5V + 160mA@24V backplane
• MicroLogix 1500​ – Legacy Rockwell controller that uses 1769 racks as expansion I/O; 1769-PA2​ powers the expansion rack when the MicroLogix 1500 base 24V supply is insufficient for added I/O
• 5069-PA4​ – Forward-path replacement AC power supply for 5069 Compact I/O on 5380/5480 CompactLogix/ControlLogix; migration path from 1769-PA2​ when upgrading to newer 5069 I/O