ACB Circuit Breaker Contact & Silver Spot Welding Machine

Equipment Overview

This high-precision servo spot welding machine is developed for welding silver contacts and copper components used in ACB and MCCB circuit breaker manufacturing.

The machine integrates advanced servo pressure control technology, customized precision fixtures, and an efficient water cooling system to achieve stable welding quality and high repeatability.

Compared with conventional pneumatic welding machines, the servo welding system provides more accurate pressure control, reduced welding deformation, and better consistency for silver contact welding applications.

The customized tooling fixtures are designed according to different product models, ensuring accurate positioning, fool-proof operation, and quick product changeover.

Widely used in low-voltage electrical manufacturing industries, the equipment is suitable for ACB, MCCB, contact assemblies, switchgear components, and other precision resistance welding applications.

Technical Specifications

Application Scope

The equipment is widely used in the manufacturing of:

• Moulded Case Circuit Breakers (MCCB): Moving and static contact assemblies for 63A, 125A, 250A, 400A, 630A, 800A
• Air Circuit Breakers (ACB): Main contacts for 1000A to 6300A draw-out and fixed-type heavy-duty circuit breakers
• Other Electrical Components: High-voltage contactors, EV Relays (DC fast-charging relays), and universal transfer switches

After-Sales Service & support

We are committed to long-term cooperation with full technical support:

✅1-Year Free Warranty ：Covers all non-human damages. Replacement and repair included.

✅Lifetime Maintenance Support：We offer lifelong technical assistance and spare parts supply.

✅On-Site Installation & Commissioning：Professional engineers are available to visit your site for setup .

✅Operator Training：On-site or remote training to ensure your team can run the machine independently.

✅Remote Technical Support：Quick response via video call, remote control, Email, WhatsApp, and WeChat.

References & Case Studies

Our Production Facility	At the customer's site	Custom spot welding machine

Q&A (FAQ)

Q1: Why is a Medium Frequency Inverter DC (MFDC) welder recommended for circuit breaker silver contacts?
A: Both silver (Ag) and copper (Cu) possess extremely high thermal and electrical conductivity. Traditional AC welding disperses heat, which often leads to the melting and deformation of the silver contact surface. An MFDC spot welder (1000 Hz) reacts in milliseconds, concentrating energy precisely at the mating surface to form a well-proportioned weld nugget. This ensures maximum shear strength while keeping the Heat-Affected Zone (HAZ) remarkably small, preserving the mechanical accuracy of the breaker.

Q2: Why use an electric cylinder instead of a standard pneumatic cylinder for spot welding?
A: Pneumatic cylinders rely on compressed air, which can cause harsh mechanical impacts when the electrode strikes the product. A servo-driven electric cylinder provides smooth, programmable descent and exact force application. This high-precision control protects the surface of the silver contacts from impact damage, deformation, or micro-cracking, resulting in a structurally superior and visually clean weld.

Q3: What are the advantages of a spot welding machine for circuit breaker manufacturing?
A: While fully automatic lines are ideal for massive runs of a single component, a spot welding machine with custom fixtures offers unmatched flexibility. It allows operators to easily switch between different MCCB or ACB frame sizes by simply swapping the customized tooling. It is the perfect solution for manufacturers managing high-mix production schedules who still require automated, highly monitored welding execution.=

Q4: How does the real-time current monitoring improve quality control?
A: The industrial touch screen displays the active welding current waveform for every single cycle. If there is a sudden drop or spike in current—often caused by surface contamination or improper seating in the fixture—the HMI flags the fluctuation instantly. This ensures that every welded contact meets strict shear strength and electrical conductivity standards.