Allen-Bradley 140MT-C-AFA11 — Auxiliary Contact Specs & Buyer Guide

By Abdullah Zahid
15 min read
Allen-Bradley 140MT-C-AFA11 front mount auxiliary contact block 1 NO 1 NC for 140MT motor protection circuit breaker

Allen-Bradley 140MT-C-AFA11 Front Mount Auxiliary Contact, 1 NO 1 NC, for 140MT Motor Protection Circuit Breaker and 140UT Circuit Breaker — Specs, Pricing and Alternatives

When a controls engineer or panel builder is sourcing a signaling accessory for an Allen-Bradley 140MT or 140UT breaker installation, the Allen-Bradley 140MT-C-AFA11 is typically the first catalog number that comes up — and for good reason. This front-mount auxiliary contact block adds exactly 1 normally open (NO) and 1 normally closed (NC) contact to either a 140MT motor protection circuit breaker or a 140UT circuit breaker, providing the discrete status and interlock signals that PLC inputs, control relays, and indicator circuits depend on. Getting the right variant confirmed before ordering is what separates a smooth panel build from an avoidable delay.

If you have already confirmed this is the correct part for your application, check current pricing and availability at LeadTime.ca — ships worldwide.

Who Should Buy the Allen-Bradley 140MT-C-AFA11 — and Who Shouldn't

This accessory is right for engineers, electricians, OEM panel builders, and MRO buyers who already have 140MT or 140UT breakers installed and need a front-mount auxiliary contact block that provides one NO and one NC output for status or interlock wiring. Confirm each of the following before ordering:

  • Your breaker is a 140MT motor protection circuit breaker or a 140UT circuit breaker — not an older 140M or any other Allen-Bradley family.
  • Your panel layout allows a front-mount accessory; if a side-mount block is required, a different catalog number applies.
  • Your control logic is satisfied by 1 NO and 1 NC — if you need 2 NO or 2 NC independently, a different variant is the correct choice.
  • Your control circuit voltage and current load (PLC input card, control relay coil, indicator lamp) fall within the auxiliary contact's rated limits as listed in the Rockwell datasheet.
  • You have confirmed the specific 140MT or 140UT frame size and series is listed as compatible in the Rockwell accessory cross-reference.

If your site is standardized on a non-Rockwell breaker ecosystem, or if your application demands specialized contacts such as early-make or late-break signaling, this accessory is not the correct fit — see the variant and alternatives section below for the right direction.

On this page:

What the Allen-Bradley 140MT-C-AFA11 Actually Does in a Control System

The Allen-Bradley 140MT-C-AFA11 is a front-mount auxiliary contact block — not a protective device and not a load-switching component. Its sole function is to mirror the mechanical state of the 140MT or 140UT breaker it is attached to, providing 1 NO and 1 NC dry contact outputs to the control circuit. When the breaker is in the ON position, the NO contact closes and the NC contact opens; when the breaker trips or is manually switched OFF, the states reverse. This gives downstream devices — PLC digital input cards, control relays, indicator lamps, SCADA I/O — a clean, real-time status signal without any load current passing through the auxiliary block itself.

The practical value is significant. Without an auxiliary contact on a 140MT breaker, a PLC has no direct way to know whether the breaker has tripped, been manually turned off for maintenance, or is still in normal operation. Adding the 140MT-C-AFA11 closes that loop instantly. Panel builders routinely include it as a standard accessory on every motor starter assembly that feeds a supervised drive or conveyor, and maintenance teams use it to enable trip alarms that flag problems before a process shutdown causes production losses.

The front-mount design is deliberate: it attaches directly to the face of the 140MT or 140UT breaker unit, keeping the auxiliary block within the breaker's footprint rather than requiring additional DIN rail space to the side. This is particularly relevant in compact motor control center (MCC) buckets and OEM panel builds where horizontal space on the rail is already allocated.

Typical System Architecture: Where This Contact Block Sits

The 140MT-C-AFA11 sits between the 140MT or 140UT circuit breaker and the control-level wiring that reports breaker state to supervisory logic. It does not handle motor load current at any point in the signal chain.

  • Upstream: Three-phase line supply fed through the 140MT motor protection circuit breaker or 140UT circuit breaker.
  • The 140MT-C-AFA11 mounts to the front of the breaker and mechanically links to its switching mechanism.
  • NO terminal wired to a PLC digital input (or control relay coil) to confirm breaker-closed / motor-running status.
  • NC terminal wired to a PLC digital input or alarm relay to signal breaker-open or trip condition.
  • Downstream of the auxiliary: control logic in the PLC or relay ladder acts on the status signal for permissive interlocks, HMI indicators, or alarm annunciators.

Industries and Applications Where the 140MT-C-AFA11 Is Used

In general manufacturing and OEM machinery, the 140MT-C-AFA11 appears on virtually every 140MT breaker that feeds a monitored motor — conveyor drives, pump motors, fan starters, and compressor circuits where the PLC needs to distinguish between a running motor and a tripped or manually isolated one. Panel builders for packaging lines, assembly equipment, and food and beverage machinery routinely specify it as a default accessory on all 140MT-based motor starter assemblies.

Material handling applications, including warehousing conveyors, sortation systems, and overhead cranes, use the auxiliary contact to build interlock chains between adjacent drive sections. If one conveyor's 140MT breaker trips, the NC contact opens and the preceding conveyor's PLC permissive is removed, preventing product pile-up upstream.

In HVAC and building systems, the 140MT-C-AFA11 provides the trip indication signal that drives BMS (Building Management System) alarm points without adding relay hardware between the breaker and the control panel. Water and wastewater facilities use similar wiring on pump motor circuits to enable remote monitoring of breaker states via SCADA I/O cards.

Retrofit and MRO applications are also common: when an existing 140MT or 140UT installation did not originally include an auxiliary contact but a controls upgrade requires status signaling, the front-mount design of the 140MT-C-AFA11 allows it to be added without replacing or rewiring the base breaker.

Application Typical Deployment
Conveyor and material handling NO contact to PLC input for running status; NC contact for trip alarm interlock to upstream section
Pump motor starters (water/wastewater) NC contact drives SCADA alarm point; NO contact confirms pump available
OEM packaging machinery Front-mount auxiliary added to every 140MT on the panel; status fed to machine HMI via PLC I/O
HVAC fan and air handling units NO contact confirms breaker ON to BMS; NC contact triggers maintenance alarm on trip
MRO retrofit on existing 140MT/140UT installations Front-mount accessory snapped onto existing breaker; no rewiring of load side required

Key Specifications and Compatibility

Parameter Value / Description
Brand Allen-Bradley (Rockwell Automation)
Catalog Number 140MT-C-AFA11
Product Type Front mount auxiliary contact block
Contact Configuration 1 NO + 1 NC
Compatible Devices 140MT motor protection circuit breaker; 140UT circuit breaker
Mounting Position Front mount on breaker
Control Circuit Duty Signaling and interlock only — not for motor load switching
Terminal Type Screw clamp terminals for control wiring
Standards and Approvals Refer to current Rockwell Automation datasheet for IEC, UL, and CSA listings
Electrical Ratings Refer to current Rockwell Automation datasheet for AC/DC voltage, current, and utilization category ratings

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

140MT-C-AFA11 vs Other 140MT Auxiliary Contact Variants

The 140MT accessory family includes multiple auxiliary contact configurations beyond the 1 NO + 1 NC block. The choice between them is driven entirely by how many independent signals your control logic requires and whether your panel layout accommodates a front-mount or side-mount block.

Catalog Feature 140MT-C-AFA11 2 NO Variant 2 NC Variant Side-Mount Variant
Contact Configuration 1 NO + 1 NC 2 NO 2 NC Varies by catalog
Mounting Style Front mount Front mount Front mount Side mount
Compatible Devices 140MT, 140UT 140MT, 140UT 140MT, 140UT 140MT, 140UT
Best For Mixed status + interlock with single block Two independent normally-open signals Two independent normally-closed signals Panels with no front-mount clearance
When to Choose Most standard applications Dual permissive logic or redundant run confirmation Dual trip alarm or safety interlock chains Space constraint on door or breaker face

Note: Exact catalog numbers for 2 NO, 2 NC, and side-mount variants should be confirmed against the current Rockwell Automation 140MT accessory selection guide before ordering. If your application requires more than two contacts from a single breaker, consult the full 140MT accessory catalog — check current availability at LeadTime.ca and our team can help confirm the right variant.

Expert Verdict: Is the 140MT-C-AFA11 the Right Call for Your Project?

The Allen-Bradley 140MT-C-AFA11 is the default, correct choice for any controls engineer or panel builder who needs basic status and interlock signaling on a 140MT motor protection circuit breaker or 140UT circuit breaker. The 1 NO + 1 NC configuration covers the vast majority of standard PLC input wiring, indicator lamp circuits, and interlock chain logic in a single block, and the front-mount installation keeps the panel footprint clean without consuming additional DIN rail width. Rockwell Automation specifies it explicitly for these two breaker families, and it installs in a consistent, repeatable way that experienced Allen-Bradley panel builders will recognize immediately. For OEMs standardizing their motor starter designs across a full product line, this level of predictability matters.

Where the 140MT-C-AFA11 is not the right answer is equally important to understand. If your control logic requires two independent NO signals — for example, separate run confirmation to two different PLC input cards — a 2 NO variant from the 140MT accessory family is the correct part, not this one. If your panel layout has no clearance at the breaker face and only allows a side-mount block, a different catalog number applies. And if the project involves a non-Rockwell breaker ecosystem — a Siemens 3RV2 motor protector or a Schneider Electric GV2 series, for example — those families use their own accessory blocks (such as the Siemens 3RV29xx range or the Schneider GVAE11 type) which are functional equivalents in purpose but are not physically interchangeable with the 140MT-C-AFA11. Mixing accessories across breaker families is a wiring and mechanical incompatibility, not just a preferences issue.

From a procurement standpoint, the 140MT-C-AFA11 is a standard stocked item at major authorized Rockwell distributors, meaning it is not a long-lead or special-order accessory under normal supply conditions. For facilities managing spare parts inventories on critical production motors, keeping one or two units on the shelf alongside the 140MT breakers themselves is straightforward practice. Ordering through a specialist automation distributor rather than a general supply channel gives you the added assurance of compatibility confirmation before the part ships — particularly valuable when retrofitting onto older 140MT installations where frame series details may not be immediately obvious. View current pricing and stock status for the 140MT-C-AFA11 at LeadTime.ca — we ship worldwide.

For volume pricing, project-quantity quotes, or to confirm lead time against your build schedule, contact the LeadTime.ca team directly — we ship worldwide.

Pricing, Availability, and Lead Time for the 140MT-C-AFA11

The Allen-Bradley 140MT-C-AFA11 is a standard accessory catalog number within the 140MT family and is commonly stocked by major authorized Rockwell Automation distributors across North America, including Canada. As a frequently specified accessory on motor starter panels, it does not typically require special ordering under normal supply conditions. Pricing is available on the product page, and current stock levels are confirmed in real time when you access the listing.

When stock is not immediately available from a regional warehouse, typical lead time patterns for Allen-Bradley accessories of this class range from weeks to several weeks depending on current supply conditions and distributor inventory positions. Canadian buyers sourcing through authorized Rockwell distributors will find similar availability patterns to US-based warehouses, though it is practical to confirm specific lead times with your distributor before committing to a build schedule, particularly when ordering for new installations rather than MRO replacement.

For facilities with critical motors or high-volume OEM production, carrying a small on-hand spare quantity of the 140MT-C-AFA11 alongside spare 140MT breakers eliminates any lead-time risk on unplanned replacements. Pricing is never a reason to substitute a different variant — at this accessory's typical price point, the cost of a mis-order, return, and re-order cycle is substantially higher than stocking the correct part from the outset.

What Engineers Need to Know Before Ordering the 140MT-C-AFA11

Community and forum discussions of the Allen-Bradley 140MT-C-AFA11 by catalog number are sparse — which is actually a reliable signal. Accessories that perform exactly as expected rarely generate online complaint threads. At the 140MT family level, the consistent message from engineers and electricians on platforms including PLCTalk, PLCS.net, and the Reddit automation communities is that Allen-Bradley motor protection accessories install predictably and behave as the datasheet describes. The issues that do get discussed are almost universally about selection and wiring rather than product failure.

The ordering mistake that appears most often across these communities — and the one that causes the most avoidable delays — is confusing accessories between Allen-Bradley breaker families. The 140MT and the older 140M family are not the same, and their accessories are not interchangeable. A buyer who orders a 140M-series auxiliary contact against a 140MT breaker will discover a physical mismatch at installation, not at the ordering stage. The same confusion applies to contact configuration: ordering a 2 NO block when the design calls for 1 NO and 1 NC (or the reverse) results in rework that a simple pre-order check of the control schematics would prevent. When community data for a specific model is limited, that is precisely the moment where consulting a specialist distributor who can cross-check the catalog number against your breaker nameplate before the order ships adds real value.

A third pattern noted across general motor breaker accessory discussions is the wiring of NO and NC terminals in reverse — connecting the control circuit to what is assumed to be the normally open terminal when it is actually the normally closed, or vice versa. The result is inverted PLC logic: a trip condition reads as a run confirmation, and the motor appears healthy when the breaker has opened. A continuity test before connecting to PLC inputs costs two minutes and eliminates that risk entirely. These are not exotic failure modes — they are the predictable consequences of skipping catalog verification and pre-commissioning checks, and they appear in maintenance logs far more often than they should.

Wiring and Installation Overview for the Allen-Bradley 140MT-C-AFA11

  • De-energize and lock out both the motor circuit and the control circuit before mounting or wiring the auxiliary contact block — the 140MT-C-AFA11 mounts to the front face of the 140MT or 140UT breaker while both are in a dead state.
  • Align the auxiliary block with the designated front-mount engagement point on the breaker and secure it according to the Rockwell installation manual; confirm firm mechanical attachment with no play before proceeding to wiring.
  • Identify NO and NC terminals using the terminal markings on the device face and the official Rockwell datasheet — do not rely on position alone, and perform a continuity test across each terminal pair before connecting to the control circuit.
  • Route control wiring to the screw clamp terminals using the wire size, stripping length, and tightening torque values specified in the Rockwell datasheet; keep control wiring physically separated from load (power) wiring to avoid noise coupling on PLC inputs.
  • After wiring, restore control power and functionally test by manually toggling the breaker from OFF to ON and confirming that the PLC digital input states or continuity readings match the expected NO/NC behavior before returning the circuit to service.

Wrong-Part Prevention Checklist Before Ordering the 140MT-C-AFA11

Review every item below against your application before placing the order. Each check reflects a real source of mis-order delays identified in this product family.

  1. Confirm the breaker family: this accessory is for 140MT motor protection circuit breakers and 140UT circuit breakers, not older 140M or other families.
  2. Confirm mounting style: 140MT-C-AFA11 is a front-mount device; do not order it if a side-mount auxiliary block is needed.
  3. Check contact configuration: verify that 1 NO + 1 NC meets your PLC input/interlock requirements; if you need two NO or two NC, choose another variant.
  4. Check control voltage/current: ensure the auxiliary contact ratings match your control circuit supply (e.g., 24 VDC, 120 VAC) and load (relays, PLC inputs).
  5. Verify breaker frame size and type: confirm compatibility with the specific 140MT/140UT frame in the panel.
  6. Confirm quantity per starter: many applications need one auxiliary per breaker; some interlock schemes may need more.
  7. Check environmental conditions (temperature, pollution degree, IP rating of the assembly) against the datasheet.
  8. Verify local codes/standards: if used in safety-related circuits, confirm suitability against applicable standards and Rockwell guidance.

If any item on this checklist raises a question before you order, contact the LeadTime.ca team — we can verify compatibility against your breaker nameplate and control circuit requirements before the order ships.

Frequently Asked Questions

Does the 140MT-C-AFA11 work with all catalog numbers in the 140MT motor protection circuit breaker range, or only specific frame sizes?

The Allen-Bradley 140MT-C-AFA11 is listed by Rockwell Automation as compatible with 140MT motor protection circuit breakers and 140UT circuit breakers as a product family. However, Rockwell's accessory cross-reference documentation should always be checked against the specific 140MT or 140UT catalog number on your breaker nameplate to confirm that no frame-size or series restriction applies. When in doubt, confirm with an authorized distributor before ordering.

How do I identify which terminals on the 140MT-C-AFA11 are NO and which are NC?

Terminal designations for NO and NC contacts are marked directly on the device face and are detailed in the Rockwell Automation installation datasheet for the 140MT-C-AFA11. Always verify terminal identity with a continuity test — with the breaker in the OFF position, the NC contact should show continuity and the NO contact should show open circuit. Do not rely on physical position alone, as terminal labeling conventions can differ from assumptions based on other brands' accessories.

Can the auxiliary contacts on the 140MT-C-AFA11 be wired directly to 24 VDC PLC digital inputs without an interposing relay?

This depends on whether the 140MT-C-AFA11's auxiliary contact ratings cover the specific 24 VDC input circuit's voltage and current requirements of your PLC input card. The auxiliary is a control-circuit device, not a load-switching device, and is generally suitable for low-current PLC input wiring. Confirm the exact voltage and current ratings from the current Rockwell datasheet against your PLC input card specifications before wiring directly, and add an interposing relay if the load exceeds rated limits.

Can the 140MT-C-AFA11 be added to an existing 140MT or 140UT installation that was originally built without an auxiliary contact?

Yes — the front-mount design of the 140MT-C-AFA11 is specifically suited to retrofits on existing 140MT and 140UT installations. It attaches to the front face of the breaker without requiring removal of the breaker from the panel or rewiring of the load side. Confirm that the existing breaker catalog number is on the Rockwell-approved compatibility list and that the front-mount position is unobstructed in the existing enclosure before ordering.

What happens if the wrong auxiliary contact variant is installed — for example, a 140M-family block on a 140MT breaker?

Accessories from other Allen-Bradley breaker families such as the 140M are not physically interchangeable with 140MT accessories. A mismatched accessory will not engage the breaker mechanism correctly and may not mount securely, leading to no contact switching, intermittent signals, or a block that appears installed but is not mechanically engaged. The correct resolution is to remove the incompatible accessory and install the 140MT-C-AFA11 or the correct 140MT-family variant as specified.

Why Order the Allen-Bradley 140MT-C-AFA11 From LeadTime.ca

  • LeadTime.ca ships worldwide — not limited to any single region or country, with global sourcing capability for Allen-Bradley automation components.
  • Specialist distributor with the product knowledge to confirm 140MT/140UT compatibility against your breaker nameplate before the order ships, reducing mis-order risk.
  • Real-time stock and pricing visibility on the product page, with the ability to contact the team directly for volume pricing or project-quantity quotes.
  • Hard-to-find or low-stock accessories sourced through authorized channels — no grey-market substitutes, no warranty risk.
  • Fast response for MRO and OEM buyers who need realistic lead-time commitments before committing to a production or commissioning schedule.

At-a-Glance Summary: Allen-Bradley 140MT-C-AFA11

  • Catalog number: 140MT-C-AFA11 — front mount auxiliary contact block from Allen-Bradley (Rockwell Automation).
  • Contact configuration: 1 normally open (NO) + 1 normally closed (NC) — the standard mixed configuration for status and interlock wiring.
  • Compatible with: 140MT motor protection circuit breakers and 140UT circuit breakers — not for 140M or other Allen-Bradley families.
  • Mounting: front mount only — a different catalog number is required for side-mount applications.
  • Control circuit duty only: not rated for motor load switching; verify AC/DC voltage and current ratings from the Rockwell datasheet against your control circuit before wiring.
  • Retrofit-friendly: can be added to existing 140MT/140UT installations without removing the base breaker from the panel.
  • Commonly stocked at major authorized distributors; not typically a long-lead item under normal supply conditions.
  • Wrong-part risk: confirm breaker family, mounting style, and contact configuration against the 8-point checklist before ordering.
  • LeadTime.ca ships worldwide — check current pricing and availability.

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