Omron CJ1W-PA202 Power Supply — CJ1 Rack Selection Guide

By Abdullah Zahid
14 min read
Omron CJ1W-PA202 AC input power supply unit mounted on CJ1 PLC rack for factory automation control panel

Omron CJ1W-PA202 Power Supply Unit – AC Input for CJ1 PLC Racks: Specs, Selection Guide & Expert Review

If you are a controls engineer sourcing a replacement power supply for an Omron SYSMAC CJ1 PLC rack, or a panel designer specifying a new CJ1-based build, the CJ1W-PA202 is the standard AC-input module to evaluate first. This unit accepts a wide AC input range of approximately 85 to 264 VAC at 50/60 Hz and delivers regulated 5 VDC and 24 VDC outputs — the two rails your CJ1 CPU and I/O modules depend on. Getting the current budget right before you order is the single most important decision point, and this guide walks you through exactly that.

If you have already confirmed the CJ1W-PA202 is the correct part, check current pricing and availability at LeadTime.ca — we ship worldwide.

Who Should Buy the CJ1W-PA202 — and Who Shouldn't

The Omron CJ1W-PA202 is the right choice when all of the following apply to your situation:

  • Your PLC platform is confirmed CJ1 — not CJ2, CS1, or a newer Omron NX/NJ platform.
  • Your panel supply is 100–240 VAC (operating range approximately 85–264 VAC) — you are not running a 24 VDC-input control architecture.
  • Your calculated 5 VDC rack current demand is within the CJ1W-PA202's rated 2.8 A output, with adequate margin for expansion.
  • Your 24 VDC auxiliary load on the rack is within the rated 0.4 A output — external sensors or heavy 24 V loads should be fed from a separate supply.
  • You are replacing an existing CJ1W-PA202 in kind, or specifying a compact CJ1 system with moderate I/O density.
  • You can install the required external branch circuit protective device (cartridge-type fuse, 30 A max, 250 VAC) upstream of this unit as Omron specifies.

If your rack's 5 V or 24 V demand exceeds these ratings, or your system runs on 24 VDC supply power, the CJ1W-PA202 is not the correct choice. The CJ1W-PA205R and CJ1W-PA205C deliver higher current on the AC-input side, and the CJ1W-PD0xx series handles DC-input architectures — both are covered in the variant comparison below.

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What the CJ1W-PA202 Actually Does in a CJ1 System

The Omron CJ1W-PA202 is the CJ1 Power Supply Unit, AC Input — a dedicated rack power module that belongs to Omron's SYSMAC CJ series. It is not a standalone DIN-rail power supply and cannot be used outside of a CJ1 rack assembly. Its role is to convert industrial mains AC power into the two regulated DC rails the CJ1 system requires: 5 VDC for the logic bus shared by the CPU and all mounted I/O and special function modules, and 24 VDC for limited auxiliary loads directly on the rack.

The module mounts at the leftmost position on the CJ1 rack, immediately to the left of the CPU unit. From there, it feeds the CJ1 backplane, which distributes 5 V to every module in that rack. The 24 V auxiliary output is available at the terminal block for powering sensors or control inputs directly off the rack — but at only 0.4 A rated output, it is suited to light loads. Anything heavier should draw from a dedicated external 24 VDC supply.

A power-OK output contact is also provided, allowing the CJ1W-PA202 to signal its operational status to a monitoring circuit or safety relay — useful for systems where power supply health needs to be tracked by an upstream supervisory layer.

Typical CJ1 System Architecture with the CJ1W-PA202

The CJ1W-PA202 sits at the power input point of the CJ1 rack, translating panel AC supply into the logic and auxiliary DC rails that every downstream component depends on.

  • Panel AC supply (100–240 VAC) → External branch circuit fuse (30 A max, 250 VAC cartridge type) → CJ1W-PA202 AC input terminals
  • CJ1W-PA202 5 VDC output → CJ1 backplane bus → CJ1 CPU unit (CJ1M, CJ1G, etc.) and all mounted I/O, communications, and special function modules
  • CJ1W-PA202 24 VDC auxiliary terminal → Limited on-rack sensor or control input loads (within 0.4 A rated output)
  • CJ1W-PA202 power-OK contact → Monitoring relay, safety circuit, or supervisory PLC input for supply status indication
  • Heavy or distributed 24 VDC field loads → Separate dedicated 24 VDC DIN-rail power supply, not sourced from the CJ1W-PA202 auxiliary output

Where the CJ1W-PA202 Is Typically Deployed

The CJ1W-PA202 is most commonly encountered in compact and mid-size CJ1 PLC installations where the total 5 V rack current demand falls within its 2.8 A rating. Packaging machinery and filling lines are a frequent home for this unit — machine builders have shipped large volumes of CJ1-based panels where the CJ1W-PA202 was the standard power supply selection. These machines often run for a decade or more, making the CJ1W-PA202 one of the most in-demand spare parts for packaging OEM service teams.

Assembly line control panels in automotive components and light manufacturing are another consistent application. Here the CJ1 rack typically handles discrete I/O and a communications module, keeping the 5 V bus current well within this unit's capacity. Food and beverage production lines share similar characteristics — moderate I/O, standard AC supply, and a strong preference for like-for-like replacement when a power supply fails.

MRO and reliability engineers managing aging CJ1 installations across water treatment facilities, printing lines, and building automation panels also specify this unit for critical spares stock — the logic being that a single spare CJ1W-PA202 per installed CJ1 system eliminates the most common single point of failure for a fraction of the cost of an unplanned shutdown.

Application Typical Deployment
Packaging machinery Direct like-for-like replacement in OEM CJ1 panels; critical spare stocked on-site
Automotive assembly lines New or replacement power supply in CJ1M/CJ1G racks controlling discrete I/O stations
Food and beverage production Maintenance replacement in long-running CJ1 installations with moderate module counts
Water and wastewater treatment Spare parts stocking for critical CJ1-based control panels to reduce unplanned downtime
Building automation and HVAC Power supply in compact CJ1 panels managing HVAC and building control sequences
OEM service and repair In-kind replacement to maintain original certifications and avoid redesign

Key Electrical Specifications and Variant Comparison

Parameter CJ1W-PA202 Notes
Brand / Series Omron SYSMAC CJ1 CJ1W-PA/PD series
Input Voltage Range 100–240 VAC nominal; approx. 85–264 VAC operating Wide-range AC input; not suitable for 24 VDC input
Input Frequency 50/60 Hz Compatible with standard industrial mains frequencies
5 VDC Output Current Approx. 2.8 A rated Main logic rail for CJ1 CPU and all rack modules
24 VDC Auxiliary Output Current Approx. 0.4 A rated Limited auxiliary rail; heavy loads require a separate supply
Operating Temperature 0 to 55 °C High ambient temperature reduces usable output headroom
Status / Monitoring Power status LED and power-OK output contact Contact available for supervisory monitoring
External Protection Required Branch circuit fuse: 30 A max, 250 VAC cartridge type Omron instruction sheet requirement; not integrated
Rack Position Leftmost unit on CJ1 rack, adjacent to CPU Standard CJ1 mechanical architecture
Mounting On CJ1 PLC rack (via rack DIN-rail or panel mounting) No separate enclosure required

Full technical specifications are available on the product page at LeadTime.ca.

Model Input Type 5 VDC Output 24 VDC Output When to Choose
CJ1W-PA202 AC (85–264 VAC) Approx. 2.8 A Approx. 0.4 A Compact to mid-size CJ1 racks; most common replacement
CJ1W-PA205R AC Higher than PA202 Higher than PA202 Larger CJ1 racks with greater 5 V or 24 V demand
CJ1W-PA205C AC Higher than PA202 Higher than PA202 High-density CJ1 configurations; plant standards requiring headroom
CJ1W-PD0xx series 24 VDC input Varies by model Varies by model Systems with 24 VDC control power architecture; not AC mains

If your calculated rack current demand approaches or exceeds the CJ1W-PA202's 2.8 A on the 5 V rail, the CJ1W-PA205R or CJ1W-PA205C is the correct step up — check current availability and consult with the LeadTime.ca team before finalizing your BOM.

Expert Verdict: Is the CJ1W-PA202 Still a Smart Buy?

The Omron CJ1W-PA202 earns its place in the spares cabinet and on new CJ1 panel BOMs for one straightforward reason: it is the correct, verified power supply for a CJ1 rack running modest to moderate I/O loads on an AC supply. Its wide operating input range of approximately 85 to 264 VAC handles the voltage variation found in most industrial plants without issue. The separate 5 VDC and 24 VDC outputs are well-matched to small and mid-size CJ1 systems, and its behavior in the field — particularly the reliability over years of continuous operation when panels are properly cooled within the 0 to 55 °C operating range — is well understood by the automation community. For maintenance teams replacing a failed unit in an existing CJ1 rack, or OEM builders who have standardized on the CJ1 platform and need a known, compatible power supply, this is the straightforward choice.

Where the CJ1W-PA202 does not belong is on large, expansion-heavy CJ1 racks where 5 V bus current is pushing close to the 2.8 A rated limit, or in any application using a 24 VDC control power architecture — the CJ1W-PD0xx series handles that use case. Equally, if your organization is planning a PLC platform migration or a greenfield project, re-investing in CJ1 hardware may not be the right strategic direction; the CJ2, NX, and NJ platforms from the same manufacturer offer a more modern architecture with a longer forward support horizon. In those scenarios, the conversation shifts from which CJ1 power supply to whether CJ1 is the right system at all. For a growing CJ1 rack that is simply outgrowing the PA202's current capacity, the CJ1W-PA205R or CJ1W-PA205C are direct, same-platform steps up.

From a procurement standpoint, sourcing the CJ1W-PA202 through a specialist automation distributor matters more than it might appear. Genuine, traceable stock is what separates a reliable spare from a unit that has unknown service history or uncertain provenance — especially as CJ1 hardware ages and some grey-market supply enters circulation. Specialist distributors also provide realistic lead time guidance for North American delivery, which is critical when you are planning a maintenance window rather than scrambling after an unplanned failure. View current stock status and pricing for the CJ1W-PA202 at LeadTime.ca — we ship worldwide and can confirm availability before you commit to a timeline.

For volume pricing, project quantities, or to confirm lead time before scheduling a shutdown, contact the LeadTime.ca team directly — we ship worldwide.

What Engineers Need to Know Before Ordering the CJ1W-PA202

Community feedback across automation forums including PLCTalk, PLCS.net, MrPLC, and the r/PLC and r/automation communities consistently points to the same themes when the CJ1W-PA202 comes up. The unit itself draws very little direct criticism — the most commonly reported praise is that CJ1 power supplies, including this model, deliver long, reliable service lives in properly cooled panels. Engineers who have managed CJ1 installations over many years describe the power supply as a set-and-forget component until ambient conditions deteriorate or rack loads grow beyond the original design. Installers note that physical replacement is uncomplicated, with the plug-in rack mounting and front-facing terminal layout making a swap straightforward even under time pressure.

The recurring problems the community reports are almost entirely self-inflicted at the specification or ordering stage rather than failures of the unit itself. The most common scenario is a rack that started life within the CJ1W-PA202's 5 V current budget but grew over time as additional I/O or special function modules were added — without anyone recalculating the current budget. The symptom is intermittent CPU resets or communication faults that are difficult to diagnose until someone measures the 5 V rail under full load. The fix is a swap to a CJ1W-PA205R or CJ1W-PA205C, not a replacement CJ1W-PA202. A second recurring issue is confusion between the AC-input PA-series and DC-input PD-series models — the part codes are similar enough that orders are placed for the wrong input type, most often when a procurement agent rather than a controls engineer is placing the order without a confirmed part number from the engineering team.

Because CJ1W-PA202-specific forum threads are less frequent than broader CJ1 family discussions, the most reliable pre-order guidance comes from engineers and specialist distributors who work with this hardware regularly rather than from aggregated community sentiment. The practical questions that matter at the purchase decision stage are: Have you calculated the 5 V and 24 V current budget for every module in the rack? Have you confirmed the panel has 100–240 VAC available rather than 24 VDC? Have you verified that the part number is exactly CJ1W-PA202 and not a different CJ series or a PD-series DC-input variant? If any of those questions give you pause, the wrong-part checklist below and a direct conversation with the LeadTime.ca team are the fastest paths to a confident order.

Wiring and Installation Overview

  • The CJ1W-PA202 must be installed at the leftmost position on the CJ1 rack, directly adjacent to the CPU unit — it is not field-relocatable within the rack.
  • AC input lines, neutral, and protective earth must be terminated at the designated input terminals; use appropriately sized copper conductors and torque terminals to Omron's specified values from the instruction sheet.
  • An external branch circuit protective device — a cartridge-type fuse rated at a maximum of 30 A and 250 VAC — must be installed upstream of the CJ1W-PA202; this protection is not integrated into the module.
  • Route AC input wiring physically separated from low-voltage signal cables within the enclosure to minimize electrical noise on the 5 V and 24 V logic rails.
  • After installation, verify the power status LED is active and measure both the 5 V and 24 V output rails under actual rack load before considering commissioning complete; use the power-OK output contact to confirm supervisory monitoring is functional if required by your design.

For full wiring diagrams, terminal designations, conductor sizing tables, and torque specifications, always refer to Omron's official CJ1W-PA/PD series instruction sheet and the CJ1 system setup manual.

Wrong-Part Prevention Checklist

Before placing an order for the CJ1W-PA202, work through each of the following checks. This list is drawn directly from the most common ordering errors and compatibility issues reported for this product:

  1. Confirm the PLC platform is CJ1, not CJ2, CS1, or newer Omron platforms.
  2. Confirm the panel has 100–240 VAC available and you are not expecting a 24 VDC-input power supply.
  3. Calculate total 5 V and 24 V current for CPU and all I/O modules; verify it is within CJ1W-PA202 limits.
  4. Check whether your design or standard requires a higher-capacity PA205 or a redundant/backup PSU strategy.
  5. Verify physical rack layout: CJ1W-PA202 is intended as the leftmost power unit on a CJ1 rack.
  6. Ensure external branch circuit protection (fuse or breaker) meets Omron's requirements for this model.

If any of these checks surfaces a question you cannot immediately answer, contact the LeadTime.ca team before ordering — confirming compatibility now is significantly faster than managing a wrong-part return under production pressure.

Frequently Asked Questions

How much current can the CJ1W-PA202 deliver on the 5 VDC and 24 VDC outputs?

Distributor data lists the CJ1W-PA202's rated output at approximately 2.8 A on the 5 VDC logic rail and approximately 0.4 A on the 24 VDC auxiliary rail. These are the values to use when calculating your rack current budget. Always verify against the latest Omron datasheet for your specific revision, and include a design margin — do not operate at or near the rated limits as a steady-state condition, particularly at elevated ambient temperatures approaching the 55 °C operating limit.

Can I run external sensors from the CJ1W-PA202's 24 VDC auxiliary output, or do I need a separate supply?

The 24 VDC auxiliary output is rated at approximately 0.4 A — suitable only for very light loads directly on the rack. For field sensors, transmitters, or any load beyond that rating, a dedicated external 24 VDC DIN-rail power supply is the correct approach. Drawing more than the rated auxiliary current risks destabilizing both the 24 V and 5 V rails, which can cause intermittent CPU or communication faults that are difficult to trace.

How do I know if my CJ1 rack is overloading the CJ1W-PA202?

The clearest indicators are intermittent CPU resets, unexplained communication module faults, or the 5 V rail measuring below specification under full rack load. The diagnostic approach is to sum the 5 V current consumption figures for every module in the rack from the Omron module manuals and compare that total to the CJ1W-PA202's 2.8 A rated output. If the calculated demand is close to or above that figure — especially after modules have been added since original commissioning — step up to a CJ1W-PA205R or CJ1W-PA205C rather than replacing the PA202 like-for-like.

What is the main practical difference between the CJ1W-PA202 and the CJ1W-PA205R or CJ1W-PA205C?

All three are AC-input power supplies for CJ1 racks with the same wide input range and the same mechanical interface. The PA205 variants deliver higher rated current on both the 5 VDC and 24 VDC outputs than the CJ1W-PA202, making them the correct choice for larger racks with more modules, communication cards, or heavier 24 V auxiliary loads. If your current budget calculation shows the CJ1W-PA202 has adequate headroom with margin, there is no functional advantage to specifying a PA205 — but if the calculation is marginal, the step up is the right call.

Do I actually need the external branch circuit fuse that Omron specifies for the CJ1W-PA202?

Yes. Omron's instruction sheet explicitly requires an external branch circuit protective device — a cartridge-type fuse rated at a maximum of 30 A and 250 VAC — upstream of the CJ1W-PA202. The module does not have an integrated breaker. Relying solely on upstream panel protection without meeting this specific requirement may not satisfy Omron's installation guidelines, could affect warranty or support claims, and may not comply with your plant's electrical safety standards. Document this protection requirement in your panel design file.

Is the CJ1W-PA202 compatible with CJ1M and CJ1G CPUs, and is it still supported by Omron?

The CJ1W-PA202 is designed for the CJ1 rack platform and is compatible with CJ1 CPUs including CJ1M and CJ1G variants. The CJ1 series is a mature platform — widely installed and still supported, with parts including the CJ1W-PA202 available through specialist distributors. However, Omron has introduced newer platforms, and for new greenfield designs it is worth evaluating whether a CJ2 or NX/NJ-based system better aligns with your long-term support strategy.

Why Order the CJ1W-PA202 from LeadTime.ca

  • Global shipping — LeadTime.ca sources and ships industrial automation parts worldwide, not limited to any single region.
  • Real stock visibility — specialist automation distributors maintain traceable, genuine inventory of CJ1 parts including the CJ1W-PA202, reducing the risk of grey-market or out-of-spec units.
  • Realistic lead time guidance — if the CJ1W-PA202 is not in immediate stock, LeadTime.ca provides accurate lead time estimates before you commit to a maintenance schedule or project BOM.
  • Volume and project pricing — contact the team directly for multi-unit or project-level pricing on CJ1 spares programs.
  • Wrong-part prevention support — the LeadTime.ca team can help verify compatibility before the order is placed, particularly for replacement scenarios where the installed part number needs confirmation.

CJ1W-PA202 At-a-Glance Summary

  • Official product designation: CJ1 Power Supply Unit, AC Input — model CJ1W-PA202, Omron SYSMAC CJ1 series.
  • AC input operating range: approximately 85 to 264 VAC, 50/60 Hz — suitable for most industrial mains supplies worldwide.
  • 5 VDC output: approximately 2.8 A rated — primary logic rail for CJ1 CPU and all rack-mounted I/O and function modules.
  • 24 VDC auxiliary output: approximately 0.4 A rated — limited to light on-rack loads; heavy 24 V loads require a separate supply.
  • Operating temperature range: 0 to 55 °C — panel cooling directly impacts available output headroom.
  • External protection required: cartridge-type fuse, 30 A max, 250 VAC — upstream of the unit; not integrated into the module.
  • Rack position: leftmost unit on a CJ1 rack, immediately adjacent to the CPU unit.
  • Power-OK output contact provided for supervisory monitoring of supply status.
  • Step up to CJ1W-PA205R or CJ1W-PA205C when 5 V or 24 V demand exceeds CJ1W-PA202's ratings.
  • Use CJ1W-PD0xx series when the control panel runs on 24 VDC input rather than AC mains.

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