Schneider Electric LADN11 — Auxiliary Contact Block Buying Guide

By Abdullah Zahid
13 min read
Schneider Electric LADN11 TeSys Deca auxiliary contact block 1NO 1NC screw clamp terminals for LC1D motor starter

Schneider Electric LADN11 TeSys Deca Auxiliary Contact Block (1 NO and 1 NC, Top-Mount, Screw Clamp Terminals) — Specifications, Compatibility, and Selection Guide

Controls engineers specifying accessory contacts for TeSys D motor starters typically arrive at this page with one question already half-answered: they know they need an auxiliary contact block for an LC1D contactor, and they need to confirm that the Schneider Electric LADN11 is the exact right part before the purchase order goes through. The LADN11 adds one normally open and one normally closed contact via a front clip-on snap mount — no drilling, no bracket fabrication — and is rated at 10A up to 690V AC, covering the full voltage class of standard industrial control circuits. If your base contactor falls in the LC1D09 through LC1D150 range, the LC1DT20 through LC1DT40 four-pole reversing series, or the CAD32 through CAD50 control relay family, this is almost certainly the right part.

If you have already confirmed compatibility and just need to check current pricing and stock, view the Schneider Electric LADN11 on LeadTime.ca — available and ships worldwide.

Who Should Buy the LADN11 — and Who Shouldn't

The Schneider Electric LADN11 is the right auxiliary contact block if all of the following apply to your application:

  • Your base contactor is an LC1D09 through LC1D150, LC1DT20 through LC1DT40, or CAD32 through CAD50 — not LC1E or LC1M series
  • You need exactly one normally open and one normally closed contact — not two pairs, not NO-only or NC-only
  • Your control circuit operates at or below 690V AC with a per-contact load at or under 10A
  • The front face of the contactor is unobstructed and the clip-on mounting tabs are accessible
  • You are mounting only one auxiliary block to this contactor unit — the TeSys D design supports a maximum of one
  • Screw clamp terminals accepting 0.5 to 4.0 mm² wire are compatible with your panel wiring standard

If you need four contacts instead of two, the LADN22 (2NO+2NC) is the correct model. If you need normally closed contacts only, look at the LADN32. If front clip-on mounting is obstructed, the LADN40 top-mount variant is the correct alternative.

On this page:

What the LADN11 Actually Does in a Control Circuit

The Schneider Electric LADN11 is not a standalone switching device — it is an expansion accessory that clips onto an existing TeSys D contactor or control relay and mirrors the state of the main contacts in the auxiliary contact domain. When the contactor coil energizes and the main power poles close, the LADN11's normally open contact closes and its normally closed contact opens simultaneously. This instantaneous, no-time-delay operation makes the LADN11 appropriate for interlock logic, permissive circuits, PLC input feedback, and status indication — all control-level functions that do not involve the motor power circuit directly.

The screw clamp terminal design accepts 0.5 to 4.0 mm² wire, which covers the full practical range of control signal wiring used in industrial panels. The IP2x protection rating means the contact faces are finger-safe against accidental contact, an important compliance point in open-panel installations. With a mechanical life rating of 30 million operating cycles, the LADN11 is designed to outlast the contactor it mounts to in most industrial duty applications — the block is effectively a fit-and-forget component once correctly installed.

The 18-month contractual warranty from Schneider Electric and IEC 60947-5-1 and UL certification give procurement teams the compliance documentation typically required for project submittals without additional testing or qualification work.

Where the LADN11 Sits in a Typical Motor Starter System

The LADN11 occupies the auxiliary signaling layer of a motor starter assembly, sitting between the main contactor and the control or monitoring system. Its role is to translate main contact state into control-level switching signals without touching the power circuit.

  • PLC or control system output → Contactor coil (LC1D09–LC1D150 or CAD32–CAD50)
  • LADN11 clips to the front face of that contactor — one unit maximum per contactor
  • LADN11 NO contact (terminals 13-14) → PLC digital input for run-status feedback or permissive signal
  • LADN11 NC contact (terminals 21-22) → Interlock circuit to second contactor (forward/reverse prevention) or pilot light indication
  • Downstream devices: indicator lamps, safety relay inputs, solenoid pilot valves, or additional control logic branches

Typical Applications and Deployment Scenarios

Motor starter interlock circuits are the most common deployment for the LADN11. In forward/reverse starters, one LADN11's NC contact feeds into the coil circuit of the opposing contactor, preventing both from energizing simultaneously. This is a foundational safety function in conveyor drive panels, pump reversing systems, and overhead crane control assemblies.

PLC status feedback is the second most frequent use case. The NO contact wired to a digital input module tells the controller that the contactor has actually closed — not just that the output command was issued. This distinction matters in fault detection logic and in systems where contactor weld detection is a safety or process requirement.

In HVAC and building automation, the LADN11 provides the run-status signal for BMS integration on fan and pump starters, where the main contactor is a TeSys D unit and the building controller needs a dry contact input rather than monitoring the coil circuit directly.

Wastewater treatment and pump control stations use the LADN11 for remote start confirmation in distributed control panels where visual verification of contactor state is not possible from the operator station.

Application Typical Deployment
Forward/reverse motor starter NC contact interlocks opposing contactor coil circuit on LC1D contactor pair
PLC-controlled conveyor drive NO contact wired to PLC digital input for run-confirmation feedback
HVAC fan or pump starter NO contact provides BMS dry-contact run-status signal
Wastewater pump station NO contact confirms remote start at distributed panel; NC used for fault annunciation
Safety relay permissive circuit NC contact feeds safety relay enable input to prevent unsafe re-start
Packaging machine control panel Both contacts used for dual-path interlocking in multi-axis drive coordination

Electrical and Environmental Specifications

Parameter Value
Contact configuration 1 NO + 1 NC (instantaneous)
Voltage rating 690V AC (600V AC compatible)
Current rating per contact 10A
Rated making capacity 140A Irms at 690V AC (per IEC 60947-5-1)
Minimum switching voltage / current 17V / 5mA
Mechanical life 30,000,000 operating cycles
Operating temperature -5°C to +60°C
Storage temperature -60°C to +80°C
Operating altitude Up to 3,000 m
Terminal type / wire range Screw clamp / 0.5 to 4.0 mm²

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

LADN11 vs. LADN22 vs. LADN31 vs. LADN32 — Which Contact Configuration Do You Need?

Model Contact Configuration Best For When NOT to Choose
LADN11 1 NO + 1 NC Single interlock plus one feedback signal; cost-minimized standard installations When four contacts are needed or when only NO or only NC contacts are required
LADN22 2 NO + 2 NC Applications needing four auxiliary contacts; future-proofed panels; forward/reverse with dual feedback When only two contacts are needed — LADN11 is lower cost
LADN31 2 NO only Applications using only normally open contacts; no reverse interlock required When any NC contact is needed for safety interlock or fault signaling
LADN32 2 NC only Safety-only circuits requiring only closed contacts; permissive-only logic When run-status feedback via NO contact is also required

If your control logic requires four switching contacts and you are currently specifying two LADN11 blocks, note that the TeSys D design accepts only one auxiliary block per contactor — the LADN22 is the correct single-block solution in that scenario. Check current availability of the LADN11 at LeadTime.ca or contact the team to confirm which variant suits your configuration.

Expert Verdict: Is the LADN11 the Right Part for Your Project?

The Schneider Electric LADN11 earns its place as a default specification item for TeSys D-based motor starter panels precisely because it solves a common problem — needing both a feedback signal and an interlock contact from a single contactor — without adding cost, enclosure space, or wiring complexity. The snap-on clip mount and screw clamp terminals mean an experienced technician can install and wire this block in under ten minutes. The 30 million cycle rating and IEC 60947-5-1 plus UL certification mean procurement and compliance teams have nothing to justify — this is a catalogue-standard, fully documented component from a Tier 1 automation supplier. For controls engineers working on conveyor drives, pump panels, HVAC starters, or forward/reverse motor circuits built around the LC1D09 through LC1D150 range, the LADN11 is simply the correct part.

Where the LADN11 has real limits: it is an AC-only device, which eliminates it from DC control architectures without a suitable replacement in this exact form factor. The 1NO+1NC configuration is fixed — if your logic evolves to require four auxiliary contacts, you cannot add a second LADN11; you will need to swap the block for an LADN22, which means a panel revisit and rewiring. Engineers planning panels with high probability of future expansion should consider specifying the LADN22 from the outset, accepting marginally higher upfront cost to avoid a retrofit. Additionally, LC1E and LC1M series contactors use different clip interfaces — the LADN11 will physically not seat on those units. If your base contactor is not in the LC1D, LC1DT, or CAD series, do not order this part.

From a procurement standpoint, the LADN11 is a well-stocked catalogue item at major industrial distributors globally, with typical lead times in the one-to-five business day range from stock. Backorder situations are uncommon given active inventory management for this product family. Bulk pricing is available for quantities of ten and above, which matters for panel builders ordering across multiple motor starter assemblies in a single project. For current pricing and to confirm stock before committing to a project schedule, check the LADN11 product page at LeadTime.ca — we ship worldwide.

For volume pricing or to confirm lead time before committing to a build, contact the LeadTime.ca team directly — we ship worldwide.

Price, Lead Time, and How to Order From Anywhere in the World

The Schneider Electric LADN11 is a standard catalogue item with consistent global availability. Typical lead times from distributor stock run one to five business days for standard orders. Bulk pricing is available for orders of ten units or more, and regional pricing variation exists between markets due to duties and currency differences — confirmed pricing is available on the product page or by contacting LeadTime.ca directly. LeadTime.ca ships worldwide, making it a practical single-source option for international projects, cross-border procurement, and emergency restocking regardless of location.

What Engineers Need to Know Before Ordering the LADN11

Community-level discussion on the Schneider Electric LADN11 is sparse — which is not a surprise for a mature, stable accessory component with a well-defined application scope and predictable installation procedure. The absence of forum controversy is itself a signal: engineers who have used this part report it as a non-issue. But the ordering mistakes that do occur with this product are consistent enough that specialist distributor guidance genuinely reduces the risk of receiving the wrong part on a project timeline.

The most common ordering error is selecting the LADN11 based on the TeSys D platform alone without confirming the specific base contactor series. LC1E and LC1M contactors carry a Schneider nameplate but use entirely different clip interfaces — the LADN11 will not seat on those units, and the mismatch is not immediately obvious from a model number alone if the buyer is unfamiliar with the physical differences between TeSys generations. A second recurring mistake is ordering two LADN11 units for a single contactor when four contacts are needed, without recognizing that the TeSys D design physically accommodates only one auxiliary block. The LADN22 is the correct solution in that scenario, but the mistake typically surfaces at installation rather than at order placement.

When community data is thin and the stakes of a wrong-part order are real — particularly on a retrofit where the panel is already assembled and the contactor face may not be physically inspectable until the technician is on-site — talking to a specialist distributor before ordering is genuinely useful. The LeadTime.ca team regularly helps engineers verify compatibility between auxiliary block catalog numbers and specific base contactor models before a purchase order is placed, which is faster and lower-risk than relying on forum searches for a component this specialized.

Wiring and Installation Overview

The LADN11 is designed for clip-on front-face mounting with screw clamp termination. Engineers handling installation should be aware of the following before beginning:

  • Confirm the base contactor is fully de-energized and isolated before mounting or wiring the LADN11 — the clip-on mount engages mechanically and the block seats against live terminal areas on an energized unit
  • The clip-on snap mount aligns with tabs on the upper portion of the contactor front face — verify these tabs are unobstructed and undamaged before attempting to seat the block; misaligned mounting produces visible gaps and unreliable contact operation
  • Terminal identification: the NC contact uses terminals 21-22 and the NO contact uses terminals 13-14 — confirm your wiring matches the correct terminal pair for each function in your control schematic
  • Screw terminals accept 0.5 to 4.0 mm² wire; strip 6-8mm of insulation per conductor and apply firm, consistent screw torque — under-torqued terminals are a leading cause of intermittent auxiliary contact faults in high-vibration installations
  • After installation, manually operate the contactor and verify that the NO contact closes and the NC contact opens as expected — use a continuity tester or multimeter to confirm state change before closing the panel

Full wiring diagrams and step-by-step installation procedures are available in the Schneider Electric TeSys D installation manual. Engineers should reference manufacturer documentation for torque specifications and terminal detail drawings.

Wrong-Part Prevention Checklist

Before placing a purchase order for the Schneider Electric LADN11, confirm each of the following — this checklist reflects the most common ordering errors reported with this product family:

  1. Verify base contactor model number matches supported range (LC1D09 through LC1D150 for standard three-pole, LC1DT20-LC1DT40 for four-pole reversing, CAD32-CAD50 for control relays)
  2. Physically inspect front face of contactor for clip-on mounting tab accessibility (small plastic or metal protrusions on upper portion)
  3. Confirm contact configuration requirement is exactly 1NO+1NC (not 2NO+2NC, 1NO alone, 1NC alone, or 2NO options)
  4. Check voltage class of application (690V AC is rated; 600V AC compatible; lower voltages may use cheaper alternatives)
  5. Confirm only ONE auxiliary block will be mounted per contactor (maximum limit in TeSys D design)
  6. Validate wire gauge compatibility for screw clamp terminals (typical range 0.5-4mm² per specification)

If any item on this checklist cannot be confirmed, contact the LeadTime.ca team before ordering — we can help verify compatibility against your specific base contactor model and application requirements.

Frequently Asked Questions

Can the LADN11 be used on an LC1E or LC1M contactor?

No. The LC1E and LC1M series use different clip interfaces from the TeSys D family. The LADN11 is designed for LC1D09 through LC1D150, LC1DT20 through LC1DT40, and CAD32 through CAD50 only. Attempting to mount it on an LC1E or LC1M contactor will result in misalignment, improper seating, and potential electrical hazard. Consult Schneider Electric documentation to identify the correct auxiliary block for those contactor series.

What happens if I need four auxiliary contacts on a single TeSys D contactor — can I install two LADN11 blocks?

No. The TeSys D design supports a maximum of one auxiliary block per contactor unit. Installing two LADN11 blocks will cause physical interference and improper seating. If four contacts are required, the correct solution is the LADN22 (2NO+2NC), which provides all four contacts in a single block that occupies the same mounting position.

Is the LADN11 rated for DC control circuits?

No. The LADN11 is rated for AC applications only. DC control architectures require DC-rated auxiliary contact blocks with appropriate arc suppression characteristics. Do not apply this block in DC control circuits even at voltages well below the 690V AC rating.

What is the minimum switching capability of the LADN11, and is it suitable for PLC input signals?

The LADN11 has a minimum switching voltage of 17V and a minimum switching current of 5mA, making it compatible with most PLC digital input modules operating at 24V DC input levels through a dry contact interface. Confirm your specific PLC input module's wet/dry contact requirements and minimum switching parameters before wiring.

How do I confirm the LADN11 is still serviceable after extended use, and when should I replace it?

The LADN11 is rated for 30 million mechanical operating cycles. In practice, replacement is triggered by erratic contact resistance readings during maintenance testing or by visible damage to the mounting clip tabs or terminal area — not by a fixed calendar interval. The block is a sealed assembly and internal contacts cannot be cleaned or adjusted; if testing indicates deterioration, replace the complete unit. Resistance testing with a digital multimeter across the NO and NC terminal pairs while manually operating the contactor is the standard field diagnostic method.

What wire gauge should I use with the LADN11 screw terminals?

The screw clamp terminals accept 0.5 to 4.0 mm² wire. For 10A control signal wiring, 1.0 to 2.5 mm² is the practical range in most panel designs. Wire smaller than 0.5 mm² is outside the rated range and will not be reliably retained by the terminal; wire larger than 4.0 mm² cannot be properly inserted and will over-stress the terminal body.

Why Order From LeadTime.ca

  • Global shipping — LeadTime.ca fulfills orders worldwide, including to regions where local distributor stock of TeSys D accessories is inconsistent or slow
  • Specialist sourcing support — the team verifies compatibility between auxiliary block catalog numbers and specific base contactor models before orders are placed, reducing wrong-part risk on tight project timelines
  • Volume pricing available for quantities of ten and above — contact for current pricing on project-quantity orders
  • Fast response on lead time confirmation — critical when the LADN11 is the last part needed to complete a panel build on a scheduled commissioning date

At-a-Glance Summary

  • Official product: Schneider Electric LADN11 TeSys Deca Auxiliary Contact Block — 1 NO and 1 NC, screw clamp terminals, front clip-on mount
  • Contact rating: 10A per contact, 690V AC rated, 600V AC compatible, instantaneous operation
  • Minimum switching: 17V / 5mA — compatible with standard PLC digital input modules via dry contact
  • Mechanical life: 30,000,000 operating cycles
  • Wire range: 0.5 to 4.0 mm² screw clamp terminals
  • Compatible base contactors: LC1D09–LC1D150, LC1DT20–LC1DT40, CAD32–CAD50 only
  • Maximum one LADN11 per contactor unit — use LADN22 when four contacts are required
  • Operating temperature: -5°C to +60°C; storage: -60°C to +80°C; altitude: up to 3,000 m
  • Protection rating: IP2x; standards: IEC 60947-5-1 and UL certified
  • Country of origin: France; 18-month contractual warranty from Schneider Electric
  • Not compatible with LC1E series, LC1M series, non-Schneider contactors, or DC control circuits

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