Schneider Electric LADS2 — Time Delay Contact Block Selection Guide

By Abdullah Zahid
12 min read
Schneider Electric LADS2 time delay auxiliary contact block front-mounted on TeSys Deca LC1D contactor in industrial control panel

Schneider Electric LADS2 Time Delay Auxiliary Contact Block: Specifications, Compatibility, and Selection Guide

If you are specifying a time-delay module for a TeSys Deca contactor installation and need on-delay switching in the 1-30 second range, the Schneider Electric LADS2 is the part to evaluate. This compact, front-mounted auxiliary contact block bolts directly onto TeSys Deca LC1D and LC1F contactors and CAD control relays, delivering a 1NO+1NC contact output rated at 10A at 690V AC — all without requiring an external timer relay or additional panel space. The key qualification question before ordering is simple: confirm your contactor model and your required delay window.

If you have already confirmed compatibility and are ready to proceed, check current pricing and availability for the LADS2 at LeadTime.ca — ships worldwide.

Who Should Buy the LADS2 — and Who Should Not

The Schneider Electric LADS2 is the right choice for engineers and panel builders already working within the TeSys Deca contactor ecosystem who need a compact, pre-certified on-delay module. This product fits your application if all of the following are true:

  • Your contactor is a TeSys Deca LC1D or LC1F, or your relay is a CAD control relay — LADS2 is not compatible with LC1E, LC1K, or other families
  • Your required on-delay falls within the 1-30 second adjustable range
  • Your control circuit voltage does not exceed 690V AC (IEC) or 600V (UL/CSA)
  • Your load does not exceed 10A continuous at rated voltage
  • Your installation requires a front-mounted contact block — rear-mount applications require a different part number
  • Your terminal practice uses screw clamp connections with 0.5-2.5 mm² (20 AWG to 14 AWG) wire

If your delay requirement exceeds 30 seconds, the LADS2 cannot be adjusted to cover it. Order LADS3 for 60-180 second delays or LADS4 for 180-600 second delays instead.

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What the LADS2 Does in a Real Control Circuit

The Schneider Electric LADS2 is a time delay auxiliary contact block belonging to the TeSys Deca product family. Its function is straightforward: it adds on-delay timing logic directly to a TeSys Deca contactor or CAD control relay without requiring a separate timer module, external relay, or additional DIN rail space. When the coil of the host contactor is energized, the LADS2 begins its timing cycle. The NC contact opens and the NO contact closes after the set delay — adjustable between 1 and 30 seconds via a front-face potentiometer. Contact switching time is specified at 40±15ms for the NC-to-NO transition.

The 1NO+1NC contact configuration means the LADS2 provides both a normally closed and a normally open output simultaneously, which supports dual-path logic in motor sequencing, safety interlock, and process delay circuits. At 10A continuous rating at 690V AC, the LADS2 covers virtually all standard industrial control voltage classes, and its simultaneous IEC, UL, and CSA certifications mean the same physical part satisfies compliance requirements across multiple regulatory jurisdictions without substitution. The fire-resistant housing meets IEC 60335-1 Clause 30.2 through verified third-party testing, which is relevant for HVAC and appliance control environments where thermal fault tolerance is part of the equipment safety case.

Typical System Architecture for LADS2 Deployment

The LADS2 sits between the host contactor coil circuit and the downstream control logic, acting as a timed gate that delays signal propagation by the set interval. In a typical deployment, the signal chain runs as follows:

  • PLC or control panel output energizes the TeSys Deca LC1D or LC1F contactor coil
  • LADS2, front-mounted to the contactor, begins the 1-30 second on-delay timing cycle simultaneously
  • During the delay period, the LADS2 NC contact remains closed and the NO contact remains open, holding downstream logic in standby
  • After the delay expires, the NO contact closes (and NC opens within 40±15ms), releasing the downstream control circuit — motor starter, secondary contactor, alarm relay, or interlock
  • Downstream device activates, completing the sequenced operation

Typical Applications and Deployment Scenarios

Motor soft-start sequencing is the most common application for the LADS2. A primary motor is energized through the main contactor, and the LADS2 delays energizing a secondary motor or load until the primary system has reached running condition — preventing inrush current overlap and mechanical shock.

In HVAC systems, the LADS2 is used to prevent rapid re-engagement of compressor contactors after shutdown. A 5-10 second hold-off after a compressor de-energizes reduces thermal and mechanical stress on the compressor drive train — a use case that aligns directly with the IEC 60335-1 Clause 30.2 fire-resistancy rating that makes this module suitable for appliance-grade environments.

Safety interlock delays are another practical deployment: the LADS2 introduces a hold-off period before the next process stage can be enabled, giving operators or upstream sensors time to confirm that the prior operation completed safely before the downstream load is allowed to start.

Pump priming sequences benefit from the 1-30 second delay range as well. An upstream pump or pressurization system is given time to stabilize before the downstream pump contactor is permitted to close, avoiding dry-start conditions.

Application Typical Deployment
Motor soft-start sequencing LADS2 delays secondary motor start until primary load reaches running speed — prevents inrush overlap
Compressor short-cycle prevention LADS2 holds off compressor re-engagement for 5-10 seconds after shutdown in HVAC systems
Safety interlock hold-off LADS2 introduces 3-5 second delay before next process stage is enabled — allows sensor confirmation
Pump priming sequence LADS2 delays downstream pump contactor closure until upstream system reaches operating pressure
Alarm reset interlocking LADS2 delays fault recovery signal to require manual hold-off before system restarts automatically

Key Specifications for Purchase Decisions

Parameter Value Notes
Contact Configuration 1NO + 1NC Simultaneous normally open and normally closed outputs
Contact Rating 10A continuous At rated voltage; applies across IEC, UL, and CSA certifications
Rated Insulation Voltage [Ui] 600V (UL/CSA), 690V (IEC) Verify certification standard required for your jurisdiction
Rated Operating Voltage [Ue] 690V AC, 25-400 Hz Covers standard industrial power frequency range
On-Delay Time Range 1-30 seconds (adjustable) Longer delays require LADS3 (60-180s) or LADS4 (180-600s)
Contact Switching Time 40±15ms NC-to-NO transition time
IP Protection Rating IP2x Per IEC 60529
Compatible Contactors LC1D, LC1F (TeSys Deca) Not compatible with LC1E, LC1K, or other families
Terminal Type Screw clamp 0.5-2.5 mm² (20 AWG to 14 AWG), solid or stranded
Mounting Location Front-mounted only Rear-mount applications require a different part number

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

LADS2 vs. LADS3 vs. LADS4: Which Timing Module Do You Need?

Model Delay Range Contact Rating Typical Application
LADS2 1-30 seconds 10A at 690V AC Motor sequencing, compressor hold-off, pump priming, safety interlocks
LADS3 60-180 seconds 10A at 690V AC Extended motor cooling periods, longer process stabilization delays
LADS4 180-600 seconds 10A at 690V AC Long thermal recovery sequences, extended restart lockout periods

If your timing sequence requires more than 30 seconds at any point in the control logic, the LADS2 cannot be adjusted to cover it — there is no field workaround. Confirm every delay window in your schematic before ordering. For guidance on which variant fits your application, review the product details at LeadTime.ca or contact the team directly for a compatibility check.

Expert Verdict: Is the LADS2 the Right Module for Your Panel?

For panel builders and controls engineers already committed to TeSys Deca contactors, the Schneider Electric LADS2 is a genuinely well-suited solution when the delay window falls within 1-30 seconds. The bolt-on integration with LC1D and LC1F contactors eliminates the external relay, the separate DIN rail position, and the additional wiring harness that an external timer would require. The 1NO+1NC contact output at 10A and 690V AC covers the overwhelming majority of industrial control circuit requirements, and the simultaneous IEC 60947-5-1, UL, CSA, VDE 0660, NF C 63-140, and BS 4794 certifications mean the same SKU can ship inside equipment destined for multiple regulatory markets without substitution — a meaningful advantage for OEMs building for international customers.

The LADS2 has real limits that matter before ordering. It is not compatible with LC1E, LC1K, or any contactor family outside TeSys Deca — and attempting to force the module onto an incompatible contactor does not produce a partially functional result; it produces a non-functioning installation and a field return. The 1-30 second delay window also has a hard ceiling: if your cooling cycle, restart lockout, or process hold-off requires even 31 seconds, you need LADS3 (60-180 seconds) or LADS4 (180-600 seconds). There is no potentiometer adjustment that bridges the gap. Engineers designing systems where timing requirements may expand during commissioning should evaluate whether LADS3 provides a more flexible ceiling. If programmable or multi-stage timing logic is required, an external timer relay or PLC-controlled output is a more appropriate architecture than any fixed-range auxiliary block.

From a procurement standpoint, the LADS2 is normally stocked through industrial distribution channels with standard lead times of 5-10 working days for North American orders. For project timelines where delay is a risk, ordering through a specialist industrial distributor rather than a general-purpose e-commerce channel gives you access to real-time stock confirmation, contactor compatibility verification, and the ability to expedite from local distribution if urgent. Working with a distributor who knows the TeSys Deca ecosystem means your entire module selection — not just the LADS2 in isolation — gets validated against your contactor model and panel design before the order ships. Check current LADS2 availability and pricing 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.

What Engineers Need to Know Before Ordering the LADS2

Because the LADS2 sits within a tightly defined compatibility envelope, the most important pre-order work is not spec-reading — it is contactor verification. The single most common ordering mistake with TeSys Deca auxiliary modules is assuming that any Schneider Electric contactor will accept any Schneider Electric auxiliary block. It will not. The LADS2 fits LC1D and LC1F contactors and CAD control relays exclusively. Panels built around LC1E or LC1K contactors require entirely different auxiliary module selections, and there is no adapter or workaround available in the field.

The second category of ordering errors involves the delay range. Engineers specifying control logic under time pressure occasionally confirm that a 1-30 second range covers their primary timing sequence — but miss a secondary sequence in the same panel that requires a 45 or 60 second hold-off. The fix after the fact is a module swap, which adds lead time and cost. The prevention is reviewing every timing step in the full schematic, not just the first or most obvious one, before placing the order. If there is any doubt about whether the 30 second ceiling is sufficient, LADS3 provides a 60-180 second range with the same contact rating and mounting interface.

A third area where specialist distributor support adds real value is compliance documentation. The LADS2 carries simultaneous IEC 60947-5-1, UL, CSA, VDE 0660, NF C 63-140, and BS 4794 certifications, along with IEC 60335-1 Clause 30.2 fire-resistancy verification. For engineers building equipment that must be filed with multiple regulatory bodies, having that documentation ready from a distributor with product knowledge — rather than assembling it from manufacturer PDFs after delivery — reduces engineering overhead at the compliance stage. When community-level discussion of a specialized component is sparse, the distributor's technical team is the practical substitute for peer experience. LeadTime.ca is the resource to consult when you need compatibility confirmation that goes beyond the datasheet.

Wiring and Installation Overview

The LADS2 mounts to the front of the TeSys Deca contactor using the bolt-on interface — mechanical connection must be confirmed tight before wiring begins. Key installation points:

  • Verify the host contactor is LC1D, LC1F, or a CAD relay before mounting; do not attempt installation on incompatible contactor families
  • Route NO and NC contact leads to their correct control circuit terminals — label all wire ends before installation to prevent contact inversion errors
  • Connect terminal wiring using 0.5-2.5 mm² (20 AWG to 14 AWG) solid or stranded conductors with screw clamp terminations
  • Set the potentiometer to the required delay within the 1-30 second range; verify actual delay time using a stopwatch under test conditions before final commissioning
  • Test NO and NC contacts under actual load conditions — do not exceed 10A continuous at rated voltage — and document switching behavior in the commissioning record

Full wiring diagrams and detailed installation procedures are available in the Schneider Electric manufacturer documentation for the TeSys Deca auxiliary contact block series.

Wrong-Part Prevention Checklist

Before finalizing the LADS2 order, work through each of the following checks against your equipment specification:

  1. Confirm the target contactor or relay is LC1D, LC1F, or CAD — LADS2 is not compatible with LC1E, LC1K, or non-TeSys platforms
  2. Verify delay time needed falls within 1-30 seconds range — longer delays require LADS3 or LADS4
  3. Check that control circuit voltage is 600V (UL/CSA) or 690V (IEC/CSA) — LADS2 rated for both; confirm certifications needed
  4. Confirm mounting location is front — rear-mounted versions require different part number
  5. Verify contact load does not exceed 10A at the specified voltage — oversized loads require heavier auxiliary contact block
  6. Check if on-delay (1NO+1NC) meets logic needs — if off-delay or other contact combination required, order different module

If any of these checks raises a question, resolve it before ordering. Contact the LeadTime.ca team to verify compatibility for your specific contactor model and control circuit requirements — or review the full product details on the LADS2 product page.

Frequently Asked Questions

Will the LADS2 fit an LC1E or LC1K contactor if I use an adapter?

No. The LADS2 is mechanically and electrically designed to interface with TeSys Deca LC1D and LC1F contactors and CAD control relays only. There is no adapter available that makes LADS2 compatible with LC1E, LC1K, or other contactor families. If your panel uses a different contactor series, you need to select the correct auxiliary module for that specific family — attempting to force-fit the LADS2 will not produce a functional installation.

Can I extend the LADS2 delay beyond 30 seconds in the field?

No. The 1-30 second on-delay range is fixed by the module's internal design — there is no field adjustment, jumper setting, or external modification that extends the ceiling. If your application requires a delay longer than 30 seconds, order LADS3 for 60-180 seconds or LADS4 for 180-600 seconds. These modules share the same contact rating and TeSys Deca mounting interface.

What happens if I wire the NO and NC contacts to the wrong terminals?

The control logic inverts: the circuit that should close after the delay will open instead, and vice versa. The equipment will fail to sequence correctly and may generate intermittent faults that are difficult to trace without a wiring diagram. Prevention is straightforward — label all contact wire ends before installation and verify with a continuity tester that the NC contact is closed and the NO contact is open in the de-energized state before commissioning under load.

Does the LADS2 meet both UL and IEC certification requirements in the same unit?

Yes. The LADS2 simultaneously holds IEC 60947-5-1, EN 60947-5-1, UL, CSA, VDE 0660, NF C 63-140, and BS 4794 certifications, plus IEC 60335-1 Clause 30.2 fire-resistancy verification. Rated insulation voltage is 600V for UL and CSA jurisdictions and 690V for IEC. This means a single SKU can satisfy compliance requirements for equipment destined for multiple regulatory markets without ordering a jurisdiction-specific variant.

Is the LADS2 a direct replacement for an external timer relay in an existing panel?

It depends on the existing architecture. If the panel already uses TeSys Deca LC1D or LC1F contactors, replacing a discrete external timer relay with the LADS2 is a valid approach — the integrated module eliminates the separate DIN rail position and wiring harness. However, if the existing external timer provides programmable or variable delay ranges, or if the panel is not built around TeSys Deca contactors, the LADS2 is not a drop-in replacement. Verify your contactor family and confirm the 1-30 second range covers all timing sequences in the circuit before treating LADS2 as an equivalent substitute.

Why Order From LeadTime.ca

  • Global shipping — LADS2 orders dispatched worldwide, not limited to any single region
  • Specialist industrial distributor with TeSys Deca ecosystem knowledge — compatibility verification before the order ships, not after
  • Access to volume pricing for panel builders and OEMs ordering multiple units — contact the team for current quotes
  • Technical support for module selection across the full LADS range when timing requirements are uncertain
  • View LADS2 pricing and availability at LeadTime.ca
  • Contact LeadTime.ca for a quote or compatibility check

At-a-Glance Summary

  • Contact configuration: 1NO + 1NC on-delay output
  • On-delay time range: 1-30 seconds, adjustable potentiometer
  • Contact rating: 10A continuous at 690V AC (IEC) or 600V (UL/CSA)
  • Contact switching time: 40±15ms (NC-to-NO transition)
  • IP protection: IP2x per IEC 60529
  • Compatible contactors: TeSys Deca LC1D, LC1F; CAD control relays only — not LC1E or LC1K
  • Mounting: Front-mounted bolt-on only; rear-mount requires different part number
  • Terminal: Screw clamp, 0.5-2.5 mm² (20-14 AWG), solid or stranded
  • Certifications: IEC 60947-5-1, EN 60947-5-1, UL, CSA, VDE 0660, NF C 63-140, BS 4794, IEC 60335-1 Clause 30.2
  • Longer delay alternatives: LADS3 (60-180s), LADS4 (180-600s)
  • Standard lead time: 5-10 working days through industrial distribution channels

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