High-Performance Contactor Manufacturer and Supplier

CDADA is a China-based manufacturer and supplier of contactors. With our comprehensive production facilities, we offer a complete range of electrical equipment, providing you with a one-stop solution that is both high-quality and durable.

What Is a Contactor?

A contactor is an electromechanical switching device designed for repeatedly establishing and interrupting power circuits under normal load conditions. Operating on the principle of electromagnetic actuation, contactors enable low-power control signals to safely switch high-power electrical loads—typically handling currents from 9A to 1250A (extending to 5000A for specialized applications) at voltages up to 1000V AC or 1500V DC.

Unlike circuit breakers that provide protection functions, contactors are load-switching devices optimized for frequent operation. They serve as the primary control element for electric motors, lighting systems, heating equipment, capacitor banks, and power distribution circuits across industrial, commercial, and infrastructure applications.

The fundamental advantage of contactors lies in their electrical isolation capability—the control circuit (coil) and power circuit (main contacts) remain galvanically separated, allowing safe remote operation via PLCs, timers, or manual switches without direct exposure to high voltages.

Contactor Product Categories & Configurations

Classification	Type	Current Range	Key Characteristics
Current Type	AC Contactor	9A – 1250A (AC-3)	E-shaped laminated core, 600 ops/hour, compact design, AC coil 24V-380V
Current Type	DC Contactor	20A – 1000A+	U-shaped solid core, 1200 ops/hour, arc magnetic blowout, solar/battery applications
Utilisation Category (AC)	AC-1	9A – 1250A	Non-inductive loads, cos φ ≥0.95, distribution, resistive heating
	AC-2	9A – 400A	Slip-ring motors: starting, plugging, inching, 2.5×In making
	AC-3	9A – 1250A	Squirrel-cage motors: starting, stopping during running, 8×In making, 1×In breaking
	AC-4	9A – 400A	Squirrel-cage motors: starting, plugging, inching, 10×In making/breaking
	AC-6b	25A – 100A	Capacitor switching, inrush current 30×In, specific arc quenching
Pole Configuration	3-Pole	9A – 1250A	Standard motor control, three-phase systems
	4-Pole	9A – 630A	Three-phase + neutral or two-speed motors, mechanically interlocked
	2-Pole	9A – 100A	Single-phase motors, DC applications, lighting
	1-Pole	20A – 400A	DC traction, specialized applications
Mounting Type	DIN Rail	9A – 95A	35mm top-hat rail (IEC 60715), quick installation, modular
	Panel Mount	9A – 800A	Screw-fixed base, robust industrial mounting
	Plug-in/Draw-out	100A – 800A	Withdrawable for maintenance, safety shutters

Mechanical & Electrical Endurance Standards:

Mechanical Life: 3 million – 10 million no-load operations

Electrical Life: 1-2 million operations (AC-3 at rated load), 100,000-500,000 (AC-4)

Core Functions & Operating Principle

Electromagnetic Actuation System

Component	Function	Technical Specification
Electromagnetic Coil	Generates magnetic field when energized	AC: 24V, 48V, 110V, 220V, 380V (50/60Hz); DC: 12V, 24V, 48V, 110V, 220V; Inrush/Sealed power ratio 5-10:1
Fixed Core (Yoke)	Concentrates magnetic flux, provides mounting	Laminated silicon steel (AC), solid iron (DC), surface insulation ≥100MΩ
Movable Armature	Transfers magnetic force to contact mechanism	Laminated steel, pivot bearing, anti-remanent air gap
Main Contacts	Carry power circuit current	Silver or silver-alloy (AgNi, AgCdO), double-break or single-break, wiping action
Auxiliary Contacts	Control, signaling, interlocking	10A rating, NO/NC configurations, snap-action mechanism
Arc Chute	Quenches breaking arc	Ceramic splitter plates, deionizing grids, magnetic blowout (DC)
Return Springs	Ensure positive contact opening	Spring steel, fatigue life >10 million cycles, calibrated force

Operating Sequence

Closing Operation:

Coil Energization – Control voltage applied to A1-A2 terminals

Magnetic Field Generation – Current creates electromagnetic flux in core

Armature Attraction – Magnetic force overcomes spring pressure, armature moves

Contact Closure – Movable contacts engage fixed contacts with wiping action

Circuit Completion – Power flows from line terminals (L1/L2/L3) to load terminals (T1/T2/T3)

Opening Operation:

Coil De-energization – Control voltage removed

Field Collapse – Magnetic flux decays rapidly

Spring Return – Return springs drive armature to open position

Contact Separation – Arc initiation at contact gap, drawn into arc chute

Arc Extinction – Arc cooled, elongated, and deionized in splitter plates

Application Environments & Use Cases

Industry Sector	Specific Application	Typical Specifications
Industrial Automation	Motor control centers, conveyor systems, pumps, compressors	9A-400A, AC-3, 3-pole, 380V/50Hz, DIN rail, 3 million mechanical ops
HVAC Systems	Chillers, air handling units, fan coil units	18A-95A, AC-3, 4-pole for fan speed control, 220V coil
Renewable Energy	Solar inverters, battery storage, EV charging infrastructure	100A-800A, DC contactors, 1000V/1500V DC, arc blowout, high endurance
Power Distribution	Capacitor banks, power factor correction, transformer switching	100A-630A, AC-6b, inrush withstand 30×In, dedicated capacitor contactors
Oil & Gas / Mining	Drilling rigs, conveyor belts, hoists, crushers	200A-800A, AC-4, robust construction, tropicalized (T2), high shock resistance
Infrastructure	Metro traction, railway signaling, airport baggage systems	400A-1000A, DC contactors, high mechanical endurance, redundant coils
Commercial Buildings	Lighting control, elevator systems, fire pumps	25A-100A, AC-1, 4-pole, central battery monitoring, emergency power switching
Marine & Offshore	Shipboard power, offshore platforms, port cranes	100A-400A, corrosion-resistant, 55°C ambient, vibration resistant

Manufacturing Process & Production Workflow

Precision Manufacturing Sequence

Raw Material IQC → Laminated Core Production → Coil Winding & Impregnation → Contact System Fabrication → Arc Chute Assembly → Mechanism Integration → Primary Assembly → Coil Pickup Voltage Calibration → Comprehensive Testing → Final QC → Packaging

Critical Manufacturing Stages

Stage	Process Details	Quality Control Points
Laminated Core Production	Silicon steel sheet (0.35-0.5mm) stamping, annealing at 750-800°C in hydrogen atmosphere, surface insulation coating, stacking & riveting	Core loss <3 W/kg at 1.5T, insulation resistance >100MΩ, stacking factor ≥0.95
Coil Winding	Enameled copper wire (Class F 155°C or Class H 180°C), automated winding with tension control, vacuum varnish impregnation (polyester or epoxy)	Turns ±1%, DC resistance ±5%, dielectric strength 2kV/1min, impregnation uniformity
Contact Fabrication	Silver-nickel (AgNi 90/10) or silver-cadmium oxide (AgCdO) contact tips, brazing to copper carriers, progressive stamping	Hardness HV 80-120, contact resistance <50μΩ, silver thickness ≥3mm (main), brazing strength >50MPa
Arc Chute Construction	Ceramic splitter plates (6-12 plates), steel arc runners, deionizing grids, optimized arc chamber geometry	Dielectric strength >2.5kV, arc quenching time <10ms at 400V, dimensional ±0.1mm
Mechanism Assembly	Spring steel charging system, toggle mechanism, anti-bounce buffers, contact pressure springs	Mechanical endurance 10 million cycles, contact pressure 8-15N/mm², bounce time <3ms
Final Calibration	Pickup voltage (0.85-1.1×Us), dropout voltage (0.2-0.75×Us), coil power consumption, contact timing	100% automated testing, data logging, traceability QR coding

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, permeability >5000, magnetostriction low
Coil Wire	Enameled round copper wire, Class F (155°C) or Class H (180°C)	IEC 60317, NEMA MW 35/80	Breakdown voltage >2kV, solderability 390°C/2s, flexibility 1× diameter
Coil Bobbin	PA66 GF30 or PBT GF30, flame retardant	UL 94 V-0, IEC 60664	Tracking index >600V, heat resistance 180°C, dimensional stability
Main Contacts	Electrolytic copper (Cu-ETP C11000) + AgNi 90/10 or AgCdO tips	ASTM B152, IEC 60368	Conductivity ≥100% IACS, arc erosion resistance, anti-welding
Contact Springs	Beryllium copper (CuBe2 C17200) or stainless steel 301	ASTM B196	Fatigue life >10 million cycles, contact pressure consistency ±10%
Arc Chute Plates	Steatite ceramic or alumina (Al₂O₃ 95%), cold-rolled steel arc runners	IEC 60672	Heat resistance >1000°C, dielectric strength >15kV/mm, arc quenching
Return Springs	Oil-tempered carbon steel SWOSC-V or 17-7PH stainless steel	JIS G 3560, ASTM A313	Tensile strength 1800-2200MPa, relaxation <5% at 20 years, fatigue >10⁷ cycles
Enclosure/Base	BMC (DMC-2) thermosetting plastic or PA66 GF30 thermoplastic	IEC 60664-1, UL 94 V-0	Tracking index >600V, impact strength >7 kJ/m², flame retardant
Terminals	Brass C36000 or copper C11000 with tin plating (5-8μm)	ASTM B16/B187	Current density 1.0-1.5 A/mm², torque withstand 1.5-5.0Nm, corrosion resistance
Fasteners	Stainless steel A2-70 or zinc-plated steel 8.8	ISO 3506, ISO 898-1	Torque consistency, corrosion resistance, vibration locking

Standards Compliance & Testing Protocols

International Standards Framework

Standard	Scope	Applicable Ratings
IEC 60947-4-1	Contactors and motor starters - Electromechanical contactors and motor starters	Global baseline for AC/DC contactors up to 1000V AC / 1500V DC
IEC 60947-4-2	AC semiconductor motor controllers and starters	Solid-state contactors, soft starters
GB/T 14048.4	Chinese national standard equivalent	CCC certification, China market

Mandatory Type Tests (IEC 60947-4-1)

Test Category	Specific Test	Acceptance Criteria
Temperature Rise	Continuous current at rated In	Terminals ≤80K (silver), ≤65K (bare), coil ≤85K (Class F), ≤105K (Class H)
Dielectric Properties	Power-frequency withstand (2kV-3.5kV/1min), impulse (8kV)	No breakdown, no flashover, leakage current <2mA
Making & Breaking Capacity	8×In (AC-3) or 10×In (AC-4) making, 1×In breaking	Successful operation, contact welding permissible if separable
Operational Performance	Mechanical: 3-10 million no-load cycles; Electrical: 100,000-2 million load cycles	<5% parameter drift, no mechanical failure
Overload Withstand	8×In for AC-3, 10×In for AC-4, 10 operations	No contact welding, functional after test
Short-Circuit Withstand	Coordination with SCPD (Type 1 or Type 2)	Type 2: no damage permissible, immediate reoperation; Type 1: damage acceptable with replacement
Coil Performance	Pickup voltage (0.85-1.1×Us), dropout (0.2-0.75×Us), coil consumption	Stable operation across voltage range, thermal endurance
Environmental	Damp heat, dry heat, cold, vibration, shock	Functional after conditioning, no corrosion, no parameter drift

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, micrometer
Enameled wire	Diameter, breakdown voltage, elongation, solderability	AQL 0.65	Micrometer, dielectric tester, tensile machine
Silver contact tips	Purity, hardness, density, brazing quality	Per batch	Spectrometer, hardness tester, metallurgical microscope
Plastic compounds	Glass content, viscosity, cure time, flammability	Per batch	Melt flow indexer, DSC, UL 94 test apparatus
Spring steel	Tensile strength, fatigue resistance, forming	Per batch	Tensile machine, fatigue tester, hardness tester

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, layer uniformity, resistance	Every unit	Automated winding machine with feedback, ohmmeter
Contact brazing	Temperature 780-820°C, atmosphere control, joint strength	Every 100 units	Thermocouple, shear strength tester
Mechanism assembly	Toggle force, contact gap, pressure, travel	Every unit	Force gauge, displacement sensor, automated test bench
Arc chute assembly	Plate spacing, alignment, integrity	Every 50 units	Go/no-go gauges, visual inspection

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

Test Item	Standard	Sample Size
Pickup/dropout voltage	0.85-1.1×Us pickup, 0.2-0.75×Us dropout	100%
Coil power consumption	Within ±10% of rated value	100%
Contact resistance	<50μΩ per pole	100%
Dielectric withstand voltage	2kV AC/1min (coil-circuit), 2.5kV (main circuit)	100%
Insulation resistance	>100MΩ @ 500V DC	100%
Mechanical operation	10 ON-OFF cycles, smooth operation, no sticking	100%
Timing measurement	Make time <50ms, break time <30ms (AC-3)	100%
Visual & dimensional inspection	Zero defects on critical dimensions	100%
Marking permanence	Solvent wiping, abrasion test	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	200-ton progressive die press	Laminated core stamping, contact carrier forming	5 million stampings/day
CNC Machining	5-axis vertical machining center	Precision contact machining, complex geometries	10,000 contact sets/month
Automated Winding	CNC coil winding machines with tension control	Coil production with precision layering	20,000 coils/day
Vacuum Impregnation	Vacuum pressure impregnation (VPI) system	Coil varnish impregnation, void elimination	5,000 coils/batch
Contact Brazing	Controlled atmosphere brazing furnace (H₂/N₂)	Silver tip brazing to copper carriers	3,000 contacts/hour
Assembly	Labor assembly cells	Mechanism assembly, calibration, testing	2,000 units/day per line
Testing Equipment	Automated contactor test bench (primary injection 1000A)	Pickup/dropout, timing, endurance verification	500 units/hour
	Mechanical endurance tester (10 million cycles)	Life testing, wear monitoring	100 units simultaneous
	Environmental test chamber (temperature, humidity, vibration)	IEC 60068-2 compliance	50 units/day

Production Capacity & Lead Times

Product Category	Monthly Capacity	Standard Lead Time	Urgent Order Capability
Mini contactors (9A-18A)	100,000 units	4-5 weeks	3 days (stock components)
Standard contactors (25A-95A)	80,000 units	4-5 weeks	5 days
Power contactors (115A-400A)	30,000 units	4-5 weeks	7 days
Heavy-duty contactors (500A-800A)	5,000 units	4-5 weeks	10 days
DC contactors (specialized)	5,000 units	4-6 weeks	2 weeks

Engineering & Technical Team Structure

Department	Personnel	Expertise	Responsibilities
R&D Engineering	5 engineers	Electromagnetic design, material science, contact physics, arc quenching	New product development (AC/DC), customization, patent portfolio (50+ patents)
Process Engineering	20 engineers	Lamination stamping, coil winding, brazing, assembly automation	Production line optimization, SOP documentation, yield improvement (>99%), Industry 4.0 integration
Testing & Validation	15 engineers	High-current testing, endurance validation, environmental simulation, EMC	Type testing coordination (IEC 60947-4-1), failure analysis, certification management
Application Engineering	12 engineers	Motor control, power systems, coordination studies, field commissioning	Customer technical support, scheme design, site commissioning, training
Quality Assurance	35 technicians	ISO 9001, IATF 16949, statistical process control (SPC), metrology	Supplier audit, process audit, corrective action, calibration laboratory

Certifications & Compliance Documentation

Certification	Issuing Body	Scope	Validity
ISO 9001:2015	ZHONGDA HUAYUAN	Quality management system	Annual surveillance
IEC 60947-4-1 Type Test	KEMA/DEKRA, Intertek, TÜV Rheinland	Product safety & performance	Per product series
CE Marking	Notified Body	EU market access	Design-dependent
CCC (China)	CQC	Chinese compulsory certification	5-year validity

Why Our Contactor Manufacturing Stands Apart

Our production facility represents 25 years of specialization in electromechanical switching devices, delivering contactors that exceed global standards through:

Vertical integration: In-house silicon steel lamination stamping, coil winding with vacuum impregnation, and silver contact brazing ensuring complete quality control

Advanced core technology: Proprietary lamination annealing processes achieving core losses <2.5 W/kg, contributing to 15% lower coil consumption than industry average

Customization capability: From specialized tropical coatings (T2, 55°C) to unique coil voltages, mounting configurations, and auxiliary contact arrangements—engineered to your specification

For technical specifications, motor starting calculations, coordination studies with overload relays, or factory audit scheduling, our engineering team provides direct consultation to ensure your motor control and power switching applications meet both performance requirements and long-term reliability objectives.

View as

F Contactor

If you are looking for a relibale manufacturer and supplier of F Contactor, you can choose CDADA from China, we have 40+ years of experience. IEC 60947-4-1 certified, 4P/3P, up to 1000A, AC-3/AC-4 rated. Controls motors up to 500kW. CE approved. Ideal for heavy industrial & infrastructure projects.

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D Contactor

Shanghai DADA Electric is a reliable manufacturer and we have our own brands, CDADA. Our D Contactor (LC1-D Series) is IEC 60947-4-1 certified, 3P/4P, up to 620A, AC-3/AC-4 rated. Wide coil voltage options. We recommond this product for motor control & industrial automation, contact us for a quote.

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A Series Contactor

Discover CDADA A Series Contactor—compact, reliable, and versatile for motor & circuit control. Rated 9-370A, 4-200kW (AC-3). Supports wide coil voltages (100-250VAC/DC), ideal for global projects. CCC certified. As a professional factory in China, our products have warranty, and we can offer technical services.

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CDADA is a 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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