Schneider LUA1C20 Signalling Auxiliary Contact Module for TeSys U Motor Starter

Modelo: LUA1C20 (often miswritten as LUCA1C20)

Serie: TeSysU / TeSys Ultra motor starter signalling bloque de contactos auxiliares

Tipo: Plug-in snap-on auxiliar signalling contact, mounted on LUB power base, paired with LUCA/LUCB control units

Configuración de contacto: 2NO (1NO for OF running status + 1NO for SD fault trip signal)

Terminales: Terminales de abrazadera de tornillo

Terminal numbers: 17-18 (OF running status); 97-98 (SD fault trip)

Especificaciones eléctricas

Tensión nominal de aislamiento Ui: 250V (IEC/UL/CSA)

Conventional free air thermal current Ith: 2.5A

Minimum reliable switching capacity: 17V / 5mamá (ideal for PLC digital inputs)

Estándares de cumplimiento: CEI 60947-5-1, CE, UL, CCC, Prima verde (RoHS/REACH compliant)

Peso neto: 0.03 kilos

Explicación de codificación del modelo

LUA: Auxiliary contact accessory series for TeSys U

1: Single module unit

do: Signalling contact (OF+SD start/trip interlock)

20: 2 Normalmente abierto (2NO)

Comparación: LUA1C11 = 1NO+1NC (OF+SD)

Compatible Components

Power base: LUB12, LUB32, etc..

Control unit: LUCA / LUCB / LUCC / LUCD (estándar / advanced protection units)

Montaje: Plug directly into the dedicated slot on the power base, enchufar y usar

Solicitud

Remote collection of motor running feedback (DE) and overload/short-circuit trip alarm (DAKOTA DEL SUR) by SOCIEDAD ANÓNIMA; widely used for motor status monitoring in DCS and control cabinets.

Cross-reference & Modelos equivalentes

LUA1C20: 2NO (OF NO + SD NO)

LUA1C11: 1NO+1NC (OF NO + SD NC)

Schneider does not publish separate service life data for the LUA1C module. It is mechanically coupled with the LUB power base and shares the same actuation mechanism.

1. Vida útil mecánica (LUB power base, contact actuation limit)

15 millones de operaciones (15 Mcycles) — this is the official mechanical endurance rating of the TeSys U power base. The LUA1C20 contact actuates synchronously with every motor start-stop cycle, which defines the contact’s mechanical lifetime limit.

Frecuencia máxima de funcionamiento: 3600 ciclos por hora (60 ciclos por minuto); prolonged operation above this frequency is not recommended.

2. Vida útil eléctrica (Key note: this is a low-level signalling contact, not a power contact)

This is a low-current signalling contact (Ith=2.5A, minimum switching capacity 17V/5mA). Most applications connect to PLC digital inputs (24VCC, 5~20mA).

Under low-signal conditions (24VCC, ≤10mA, non-inductive load), electrical service life approaches the mechanical life (nearly 15 millones de ciclos).

When switching AC250V near 2.5A resistive loads, electrical life drops sharply to several hundred thousand cycles (no separate AC-load electrical life published in the datasheet).

3. Difference Between OF and SD Contacts

DE (retroalimentación corriendo, terminales 17-18): Actuates on every start-stop cycle; this high-frequency contact is the lifetime bottleneck.

DAKOTA DEL SUR (fault trip, terminales 97-98): Only actuates on protection tripping; it remains stationary during normal operation, so wear is negligible and failure due to frequent cycling almost never occurs.

4. Período de garantía

Contractual factory warranty: 18 months from production date (this is not the operational service life, only the manufacturer’s liability term).

Field Service Life Estimation

Typical fan & aplicaciones de bombas (dozens of start-stop cycles daily): 5~10 years of service is common.

Frequent-cycling process equipment (multiple cycles per minute): The 15-million-cycle limit will be reached quickly; regular contact resistance testing is recommended.

Typical failure symptom: Intermittent PLC signal loss and rising contact resistance (most common with low-level DC signals).

Supplementary Reminders

The LUA1C is a pluggable accessory. When contacts wear out, only the module needs replacement; the entire LUB base does not have to be changed.

Do not use this contact to drive contactor coils or other inductive loads directly; electric arcs will burn the contacts rapidly.

Installation Instruction for LUA1C20 (TeSys U Signalling Auxiliary Contact Module)

Tipo: Snap-on plug-and-play design, installed into the dedicated accessory slot on the LUB power base (next to the control unit). No screws required.

Compatible bases: LUB12, LUB32 and other TeSys U non-reversible power bases.

1. Posición de montaje

On the front face of the LUB base, the side accessory slot (Ranura B) next to the LUCA/LUCB control unit. Only one LUA1C signalling module can be fitted per base.

Distinción: LUA1C is dedicated OF+SD status signalling contact. Do not mix its slot with LUFN auxiliary contacts or LUFDH11 modules.

2. Pasos de instalación estándar (Can be fitted live; power-off operation is recommended for safety)
3. Preparación: Align the module latches with the base slide rail, with the terminal side facing outwards (terminales 17-18 & 97-98 facing the operator for easy wiring).
4. Alignment: Insert the rear guide ribs into the internal slide rail and push horizontally.
5. Locking: Push firmly until an audible click confirms both plastic latches are fully engaged.
6. Verificación: Pull the module outward gently; if it cannot be pulled free, locking is complete. The terminal face should sit flush without tilting or warping.
7. Alambrado: Use screw terminals. DE: 17-18; DAKOTA DEL SUR: 97-98, wired to PLC DI circuits.
8. Procedimiento de eliminación (No need to disconnect main circuit or control unit when replacing the module)
9. Locate the two release latches (small tabs) on both sides of the module.
10. Press both latches inward simultaneously with fingernails or a small flat screwdriver.
11. Pull the module straight out horizontally.
12. Critical Installation Constraints & Notas
13. Secuencia de instalación: The module can be fitted either before or after the base is wired with main and secondary circuits, with no impact on existing wiring.
14. Reversed mounting is impossible: Forcing the module into the slot backwards will break the guide ribs and latches.
15. Enclavamiento mecánico: The internal actuator only meshes with the base’s operating mechanism when fully inserted. Poor engagement causes loss of OF/SD signal synchronisation and intermittent feedback.
16. Terminales: Tipo de abrazadera de tornillo (not spring terminals). Use 0.5～1.0 mm² flexible wires for 24VDC PLC signal circuits.
17. Protección ambiental: No extra cover is provided for the fitted module; terminals remain exposed. Take dustproof measures in dusty cabinet environments.
18. Common Faults Caused by Improper Installation

No OF feedback after motor closure: Módulo no completamente asentado; actuator not meshed mechanically.

No SD signal after tripping: Module tilted; only one side latch engaged.

Signal drops when lightly touched: Broken latches; the LUA1C module must be replaced.

1. LUA1C Series (Primary Signalling Contact Modules | Front Slot B on TeSys U Base)

1) Current Production Models (Standard Ordering Items)

2) Discontinued Legacy Models with Replacement Options

Regla de codificación del modelo

LUA1CXX

LUA: TeSys U auxiliary signalling contact series

1: Single module unit

do: OF+SD start/trip linked signalling contact

11 = 1NA+1NC; 20 = 2NO

1. Full List of Other Auxiliary Contacts in the Same TeSys U Series
2. LUFN (Front Main Slot, Power-Grade Auxiliary Contacts, 5A Rated)

LUFN11: 1NO+1NC

LUFN20: 2NO

LUFN02: 2CAROLINA DEL NORTE

2. LUA8E (Side-Mounted Auxiliary Contacts)

LUA8E20: 2Contacto auxiliar lateral NA

3. Dedicated Status Contacts (Viaje / Ready Position)

LUFDH11: Trip status auxiliary contact (DAKOTA DEL SUR)

LUFDA01: Ready-position contact

LUFDA10: Door interlock contact

4. Other Matching Accessories

LUFV2: Voltage monitoring module

LUFW10: Winding over-temperature protection module

LU9C1: Blank slot dust cover

III. Slot Allocation (Avoid Wrong Installation)

1. LUA1C11 / LUA1C20: Front Slot B (beside control unit), OF+SD mechanically linked; only one module allowed per base.
2. LUFN: Front Slot A, power-type auxiliary contacts.
3. LUA8E: Side slot on the power base for expanded contact capacity.
4. Universal Electrical Parameters for All LUA1C Models

Tensión nominal de aislamiento Ui: 250VCA/CC

Corriente térmica convencional Ith: 2.5A (low-level signalling only)

Minimum reliable signal level: 17V / 5mamá (PLC DI compatible)

Vida útil mecánica: Coupled with LUB base, 15 millones de operaciones.