China Modular Contactor Factory Direct

These modular contactors are provided to you by CDADA, a reliable and trusted supplier. As a direct-sales manufacturer, we possess over 15 years of experience specifically with this product series. Furthermore, our entire range of low-voltage electrical equipment—developed over many years—consistently delivers high quality and exceptional longevity; should you encounter any issues, you are welcome to contact us at any time for prompt after-sales support.

What Is a Modular Contactor?

A modular contactor is a compact, DIN rail-mounted electromechanical switching device designed specifically for building installations and domestic applications. Unlike industrial contactors governed by IEC 60947-4-1, modular contactors comply with IEC 61095—a standard with "very strict requirements, meeting the expectations of users, with regard to the safety of equipment and persons in premises and areas accessible to the public" .

These devices feature a standardized modular width (multiples of 17.5mm) enabling seamless integration into distribution panels alongside MCBs, RCDs, and other modular devices. Current ratings range from 16A to 100A, with coil voltages spanning 12V DC to 240V AC (including universal AC/DC coils), making them ideal for switching lighting, heating, ventilation, and small motors in residential, commercial, and agricultural buildings .

The latest IEC 61095:2023 Edition 3.0 introduces updated requirements for LED lighting loads (AC-7d), enhanced EMC immunity, and stricter labeling protocols—reflecting the evolution toward smart building technologies and energy management systems .

Modular Contactor Product Categories & Configurations

Classification	Type	Current Range	Key Characteristics
Utilization Category	AC-7a	16A – 100A	Slightly inductive loads: household appliances, heating, resistive loads (cos φ 0.8)
	AC-7b	16A – 63A	Motor loads: squirrel-cage motors, air conditioners, pumps (cos φ 0.45)
	AC-7d	16A – 32A	LED lighting loads (new in IEC 61095:2023), harmonic-rich environments
Pole Configuration	2-Pole (2NO)	16A – 100A	Single-phase switching, heating/lighting, most common configuration
	2-Pole (1NO+1NC)	16A – 40A	Changeover applications, dual-speed fans, reversible motors
	4-Pole (4NO)	16A – 100A	Three-phase + neutral, three-phase heating, small three-phase motors
	4-Pole (2NO+2NC)	16A – 40A	Changeover switching, generator transfer, dual supply
Coil Technology	AC Coil	24V, 110V, 220-240V	Standard 50/60Hz, audible hum during operation
	DC Coil	12V, 24V	Silent operation, battery-backed systems, control circuits
	AC/DC Universal	24-240V (auto-switching)	Hum-free operation, wide voltage tolerance, reduced inventory
	Electronic Coil	12-240V AC/DC	Low consumption (2-4VA), surge protection integrated, silent
Mounting	DIN Rail (TH35)	All ratings	35mm top-hat rail, snap-on installation, IP20 finger-safe
Mounting	Panel Mount	16A – 100A	Screw-fixed base, flat surface mounting, anti-vibration
Enclosure	Open (IP20)	All ratings	Standard modular design, distribution panel mounting
Enclosure	Enclosed (IP40-IP65)	16A – 63A	Built-in enclosure, dust/moisture protection, outdoor use

Modular Width Standards:

1 Module (17.5mm): 16A-25A, 2-pole

2 Modules (35mm): 40A-63A, 2/4-pole

3-4 Modules (52.5-70mm): 80A-100A, high-power applications

Core Functions & Operating Principle

Electromagnetic Actuation System

Component	Function	Technical Specification
Electromagnetic Coil	Generates magnetic field for contact closure	AC: 24V, 110V, 220-240V (50/60Hz); DC: 12V, 24V; AC/DC: 24-240V universal; Consumption 4-8VA (AC), 2-4W (DC)
Laminated Core	Concentrates magnetic flux, reduces eddy currents	Silicon steel E-core, surface insulation, low remanence
Movable Armature	Transfers magnetic force to contact bridge	Spring-return, anti-bounce design, <20ms response
Main Contacts	Carry power circuit current	Silver-nickel (AgNi) or silver-cadmium oxide (AgCdO), double-break wiping action
Contact Bridge	Mechanically links pole sets, ensures simultaneous operation	Copper alloy, flexible connection, self-aligning
Arc Chute	Quenches breaking arc (AC-7b applications)	Ceramic splitter plates, deionizing grids, magnetic blowout
Auxiliary Contacts	Control, signaling, interlocking (optional)	1NO+1NC or 2NO, 10A rating, snap-action

Operating Sequence

Closing Operation:

Coil Energization – Control voltage applied to coil terminals (A1-A2)

Magnetic Field Generation – Current creates electromagnetic flux in laminated core

Armature Attraction – Magnetic force overcomes spring pressure, armature moves

Contact Closure – Contact bridge engages fixed contacts with wiping action (self-cleaning)

Circuit Completion – Power flows from line terminals (L) to load terminals (T)

Opening Operation:

Coil De-energization – Control voltage removed

Field Collapse – Magnetic flux decays (AC: zero-crossing; DC: freewheeling diode)

Spring Return – Return springs drive armature to open position

Contact Separation – Arc initiation (if under load), drawn into arc chute

Arc Extinction – AC arc self-extinguishes at current zero; DC arc quenched by splitter plates

Hum-Free AC/DC Technology

Modern modular contactors feature innovative AC/DC coil designs that eliminate the characteristic 50/60Hz hum:

Duplex winding technology: Separate AC and DC coils with electronic switching

Universal voltage input: Auto-detects AC or DC supply, adjusts operation mode

Silent operation: Ideal for hotel rooms, hospitals, residential bedrooms, and noise-sensitive environments

Reduced power consumption: 50% lower holding power compared to conventional AC coils

Application Environments & Use Cases

Application	Specific Use	Typical Specifications	Utilization Category
Lighting Control	LED lighting, fluorescent lamps, discharge lamps	16A-32A, 2NO, AC-7d (LED), AC-7a (discharge), 230V coil	AC-7a / AC-7d
Heating Systems	Electric boilers, storage heaters, underfloor heating	25A-63A, 2NO or 4NO, AC-7a, 230V coil, silent operation preferred	AC-7a
Ventilation & HVAC	Extractor fans, air handling units, cooling systems	16A-40A, 2NO, AC-7b (motors), 230V coil, high switching frequency	AC-7b
Motorized Equipment	Roller shutters, garage doors, gates, awnings	16A-25A, 2NO or 1NO+1NC, AC-7b, 24V DC control (safety extra-low voltage)	AC-7b
Water Pumps	Booster pumps, circulation pumps, well pumps	16A-32A, 2NO, AC-7b, 230V coil, pump duty rated	AC-7b
Energy Management	Load shedding, peak shaving, dual-tariff switching	40A-100A, 4NO, AC-7a, 230V coil with timer/energy meter control	AC-7a
Renewable Energy	Solar PV switching, battery storage, EV charging	25A-63A, 4-pole, DC coil or AC/DC universal, extended temperature range	AC-7a / AC-7b
Agricultural	Irrigation pumps, ventilation fans, grain drying	25A-63A, IP65 enclosure, tropicalized, 400V three-phase	AC-7a / AC-7b

Dual-Tariff Applications: Modular contactors enable automatic switching between day/night electricity rates for:

Storage heaters (charge during off-peak, release during peak)

Water heaters (heat during cheap rate, maintain temperature)

EV charging (delayed start for off-peak rates)

Manufacturing Process & Production Workflow

High-Volume Precision Manufacturing Sequence

Raw Material IQC → Laminated Core Stamping → Coil Winding & Impregnation → Contact System Fabrication → Arc Chute Assembly → Mechanism Integration → Modular Housing Molding → Final Assembly → Calibration & Testing → Packaging

Critical Manufacturing Stages

Stage	Process Details	Quality Control Points
Laminated Core Production	Silicon steel sheet (0.35-0.5mm) progressive die stamping, annealing at 750-800°C in hydrogen atmosphere, insulation coating, stacking & riveting	Core loss <3 W/kg at 1.5T, insulation resistance >100MΩ, magnetic permeability >5000
Coil Winding	Enameled copper wire (0.1-0.4mm), automated winding with tension control, vacuum varnish impregnation (polyester or epoxy)	Turns ±1%, DC resistance ±5%, dielectric strength 2kV/1min, impregnation uniformity
AC/DC Universal Coil Assembly	Dual winding configuration, electronic switching circuit, surge protection integration, encapsulation	Auto-switching verification 24-240V, holding power <4VA, silent operation <30dB
Contact Fabrication	Silver-nickel (AgNi 90/10) contact tips, brazing to copper carriers, progressive stamping, wiping geometry forming	Hardness HV 80-120, contact resistance <5mΩ, brazing strength >50MPa
Modular Housing Molding	High-impact thermoplastic (PA66 GF30 or PBT GF30), 280-320°C injection, 17.5mm pitch dimension critical	Dimensional tolerance ±0.05mm, tracking index >600V, UL 94 V-0, heat resistance 160°C
Mechanism Assembly	Spring steel charging system, toggle mechanism, DIN rail clip integration, handle linkage	Mechanical endurance 100,000 cycles, contact pressure consistency, snap-on force 50-100N
Final Calibration	Pickup voltage (0.85-1.1×Us), dropout voltage (>0.2×Us), coil consumption, contact timing	100% automated testing, data logging, QR code traceability

Primary Raw Materials & Component Specifications

Component	Material Specification	Supplier Standards	Key Properties
Laminated Core	Grain-oriented silicon steel 35W300 or 50W470 (0.35-0.5mm)	IEC 60404-8-7, JIS C 2552	Core loss 2.3-3.0 W/kg at 1.5T, high permeability, low magnetostriction
Coil Wire	Enameled round copper wire, Class F (155°C) or Class H (180°C)	IEC 60317, NEMA MW 35	Breakdown voltage >2kV, solderability 390°C/2s, flexibility
AC/DC Electronic Module	PCB with SMD components, varistor, bridge rectifier, MOSFET switch	IEC 60721-3-3, IEC 61000	Wide voltage range 24-240V, surge protection, EMC immunity Level 3
Main Contacts	Silver-nickel (AgNi 90/10) or silver-cadmium oxide (AgCdO)	ASTM B152, IEC 60368	Conductivity ≥100% IACS, arc erosion resistance, anti-welding
Contact Bridge	Copper alloy (CuCr1Zr or CuNi2Si), silver-plated	ASTM B187	High conductivity, spring properties, wear resistance
Arc Chute Plates	Steatite ceramic or alumina (Al₂O₃ 95%)	IEC 60672	Heat resistance >1000°C, dielectric strength >15kV/mm
Modular Housing	PA66 GF30 (30% glass fiber) or PBT GF30	IEC 60664-1, UL 94 V-0	Tracking index >600V, impact strength >7 kJ/m², 17.5mm modularity
DIN Rail Clip	Spring steel 65Mn or stainless steel 304, zinc-plated	GB/T 1222, ISO 3506	Clamp force 50-100N, fatigue life >10,000 cycles, corrosion resistance
Terminals	Brass C36000 or copper C11000 with tin plating (5-8μm)	ASTM B16/B187	Current density 1.0-1.2 A/mm², torque withstand 1.5-2.5Nm
Return Springs	Oil-tempered carbon steel SWOSC-V or stainless steel 301	JIS G 3560, ASTM A313	Tensile strength 1800-2200MPa, fatigue life >100,000 cycles

Standards Compliance & Testing Protocols

International Standards Framework

Standard	Scope	Applicable Ratings
IEC 61095:2023 (Edition 3.0)	Electromechanical contactors for household and similar purposes	Primary standard for modular contactors, strict safety requirements for public-accessible areas
IEC 60947-4-1	Contactors and motor starters - Electromechanical contactors	Industrial standard, also applicable for higher-current modular contactors
IEC 60947-5-1	Control circuit devices and switching elements	Auxiliary contacts, control functions
GB/T 17885	Chinese national standard equivalent	CCC certification, China market

Key Difference: IEC 61095 vs. IEC 60947-4-1

IEC 61095: Stricter safety for household/public areas, utilization categories AC-7a/AC-7b/AC-7d, mandatory IP20 finger protection

IEC 60947-4-1: Industrial focus, utilization categories AC-1/AC-3, higher current ranges, different test sequences

Mandatory Type Tests (IEC 61095:2023)

Test Category	Specific Test	Acceptance Criteria
Material Performance	Ageing resistance (70°C/168h), humidity (40°C/93%RH/96h), heat resistance (ball-pressure 125°C)	No cracks, no deformation <2mm, dielectric strength maintained
Mechanical Integrity	Terminal strength (torque cycling), impact resistance (0.5J pendulum/2J sphere), screw durability	No damage, no loosening, IP rating maintained
Temperature Rise	Continuous current at rated In, terminals in free air	Terminals ≤65K (bare), ≤80K (plated), enclosure ≤40K
Dielectric Properties	Power-frequency withstand (2kV-2.5kV/1min), impulse withstand (4kV-6kV)	No breakdown, no flashover, leakage current <2mA
Making & Breaking Capacity	AC-7a: 1.5×In making/breaking; AC-7b: 8×In making, 1×In breaking	Successful operation, no contact welding, no flashover
Operational Performance	Mechanical: 100,000 cycles; Electrical: AC-7a 10,000 cycles, AC-7b 5,000 cycles	<5% parameter drift, contact wear <50%
Overcurrent Withstand	6×In for 30s (AC-7a), 10×In for 30s (AC-7b)	No contact welding, functional after cooling
Short-Circuit Coordination	Test with specified SCPD, 1kA-10kA prospective current	No enclosure damage, no hazard to operator
Environmental	EMC immunity (ESD 8kV, RF 3V/m, bursts), abnormal heat/fire (glow-wire 960°C)	Operational during/after tests, no ignition

Factory Quality Control & Inspection Standards

Incoming Material QC (IQC)

Material	Inspection Items	Sampling Plan	Equipment
Silicon steel sheets	Core loss, permeability, insulation coating, thickness	Per batch, COA + testing	Epstein frame, single sheet tester
Enameled wire	Diameter, breakdown voltage, elongation, solderability	AQL 0.65	Micrometer, dielectric tester
Thermoplastic granules	Glass content, viscosity, moisture, flammability	Per batch	Melt flow indexer, DSC, UL 94 apparatus
Silver contact tips	Purity, density, hardness, brazing quality	Per batch	Spectrometer, hardness tester
Electronic components	Function test, parameter verification, firmware version	100% AOI	LCR meter, oscilloscope

In-Process Quality Control (IPQC)

Station	Control Parameters	Frequency	Method
Core stamping	Dimensional tolerance ±0.02mm, burr <0.01mm	Every 30 minutes	Optical comparator, micrometer
Coil winding	Turns count, tension, resistance, insulation	Every unit	Automated winding with feedback
AC/DC module programming	Voltage range, switching threshold, consumption	Every unit	Programmable power supply, data logging
Contact brazing	Temperature 780-820°C, atmosphere, joint strength	Every 100 units	Thermocouple, shear tester
Housing molding	Temperature 280-320°C, pressure, dimensional	Every cycle	SCADA monitoring, SPC charts
Mechanism assembly	Toggle force, contact gap, DIN clip force	Every unit	Force gauge, automated test bench

Final Quality Control (FQC) & Outgoing QC (OQC)

Test Item	Standard	Sample Size
Pickup/dropout voltage	0.85-1.1×Us pickup, >0.2×Us dropout	100%
Coil power consumption	Within ±10% of rated (AC/DC modes)	100%
Contact resistance	<5mΩ per pole	100%
Dielectric withstand voltage	2kV AC/1min	100%
Insulation resistance	>100MΩ @ 500V DC	100%
Mechanical operation	10 ON-OFF cycles, smooth, no sticking	100%
DIN rail mounting force	Snap-on 50-100N, removal 30-80N	100%
Visual & dimensional inspection	17.5mm modularity, marking permanence	100%
EMC immunity (electronic coils)	ESD, burst, surge immunity	AQL 1.0
Packaging integrity	Drop test, vibration (ISTA 3A)	Per lot

Production Infrastructure & Manufacturing Capability

Advanced Production Equipment

Equipment Category	Machine Specification	Function	Capacity
High-Speed Stamping	100-ton progressive die press	Laminated core stamping, contact carrier forming	3 million stampings/day
Automated Winding	CNC coil winding machines	Coil production with precision layering	15,000 coils/day
Vacuum Impregnation	VPI system with polyester/epoxy resin	Coil void elimination, insulation enhancement	5,000 coils/batch
Thermoplastic Molding	80-ton injection press	Modular housing production (17.5mm pitch)	8,000 housings/day
AC/DC Module Assembly	SMT line with AOI, ICT, functional test	Electronic coil module production	10,000 modules/day
Assembly	Label assembly cells	Mechanism assembly, calibration, testing	5,000 units/day per line
Testing Equipment	Automated contactor test bench	Pickup/dropout, timing, endurance	1,000 units/hour
	Mechanical endurance tester	100,000 cycle verification	200 units simultaneous
	EMC test chamber	Immunity testing for electronic coils	100 units/day

Production Capacity & Lead Times

Product Category	Monthly Capacity	Standard Lead Time	Urgent Order Capability
Standard AC coil (16A-25A, 2NO)	100,000 units	4-5weeks	3 days
AC/DC universal coil (16A-40A)	80,000 units	4-5weeks	5 days
4-Pole contactors (25A-63A)	60,000 units	4-5weeks	7 days
High-current (80A-100A)	50,000 units	4-5weeks	10 days
Electronic coil with communication	50,000 units	4-5weeks	7 days

Engineering & Technical Team Structure

Department	Personnel	Expertise	Responsibilities
R&D Engineering	5 engineers	Building automation, silent AC/DC technology, smart grid integration, material science	New product development, IoT-enabled contactors, patent portfolio (30+ patents)
Process Engineering	15 engineers	Precision stamping, coil winding, thermoplastic molding, lean manufacturing	Production optimization, automation, yield improvement (>99%)
Testing & Validation	12 engineers	IEC 61095 compliance, EMC testing, environmental simulation, reliability engineering	Type testing coordination, failure analysis, certification management
Application Engineering	8 engineers	Building electrical design, lighting control, HVAC systems, energy management	Customer technical support, scheme design, commissioning
Quality Assurance	25 technicians	ISO 9001, ISO 14001, statistical process control, metrology laboratory	Supplier audit, process audit, corrective action

Certifications & Compliance Documentation

Certification	Issuing Body	Scope	Validity
ISO 9001:2015	ZHONGDA HUAYUAN	Quality management system	Annual surveillance
IEC 61095:2023 Type Test	VDE	Household contactor performance	Per product series
CE Marking	Notified Body	EU market access	Design-dependent
VDE Certification	VDE Testing Institute	German quality label	Per product series
CCC (China)	CQC	Chinese compulsory certification	5-year validity
CB Scheme	IECEE	International certification	Per product series

Why Our Modular Contactor Manufacturing Stands Apart

Our production facility represents 15 years of specialization in building automation contactors, delivering modular contactors that exceed global standards through:

Silent technology leadership: Proprietary AC/DC universal coil design with electronic switching, achieving <30dB operation—ideal for noise-sensitive residential and hospitality environments

Vertical integration: In-house laminated core stamping, coil winding with vacuum impregnation, and thermoplastic housing molding ensuring complete quality control and rapid customization

IEC 61095:2023 compliance: Early adoption of the latest standard including AC-7d LED lighting category, enhanced EMC immunity, and updated labeling requirements

Testing infrastructure: $2M+ invested in automated testing including 100,000-cycle mechanical endurance verification, EMC immunity testing, and environmental simulation

Smart building ready: IoT-enabled contactors with energy metering, remote control, and BACnet/Modbus integration for modern building management systems

CDADA is a Modular Contactor manufacturer and supplier in China. Our factory serves diverse industries such as power systems, building automation, and industrial manufacturing, offering flexible OEM/ODM solutions.

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