XSSR-M4 | XURUI-Zhejiang XURUI Electronics Co., Ltd.

Solid State Relay

XSSR-M4

The XSSR-M4 series is an ultra-high current AC solid state relay engineered for heavy industrial power control applications. Utilizing a screw-mount module design, press-fit thyristor technology, opto-isolated input, and reverse-parallel normally open output configuration, it delivers exceptional switching reliability under extreme electrical loads. With load current ratings up to 500A, the XSSR-M4 is ideal for industrial heating systems, induction equipment, power regulation systems, metallurgy machinery, and other high-power automation applications requiring long service life and stable performance.

Load Voltage: 75–480VAC

Control Voltage: 3–32VDC

Rated Load Current: 400A–500A

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Product Features

Low Leakage Current

Maintains stable operation with low output leakage current, helping improve load control accuracy.
Industrial Module Construction

Heavy-duty screw-mount housing and large power terminals enable secure installation and reliable operation in harsh environments.
Flexible Triggering Options

Supports both zero-cross and random turn-on switching modes to accommodate different load requirements.
Opto-Isolated Control Input

Provides safe electrical isolation between control and load circuits while improving system immunity to electrical noise.
Press-Fit Thyristor Technology

Employs high-reliability press-fit thyristor chips to ensure excellent thermal performance and long operational life.
Ultra-High Current Capacity

Designed to handle load currents up to 500A for demanding industrial power switching applications.

Product Introduction & Process

1

Electronic Component Inspection

Optocouplers, thyristors, triacs, MOSFETs, IGBTs, diodes, resistors, capacitors, varistors, LEDs, transformers, terminal blocks, ceramic substrates, PCBs, and aluminum heat sinks are inspected before production. Electrical parameters and supplier batch information are verified.

2

Power Device Selection and Matching

Power semiconductor devices are screened according to blocking voltage, trigger characteristics, leakage current, on-state voltage, current capacity, and thermal performance. Components are matched according to the required relay voltage and current rating.

3

PCB or Power Substrate Preparation

Printed circuit boards, ceramic substrates, or metal-based power substrates are cleaned and inspected. Solder pads, conductive tracks, insulation distances, and mounting surfaces are checked before electronic assembly.

4

SMT Component Placement

Solder paste is accurately printed onto the PCB. Surface-mount components are positioned by automated placement equipment and soldered through a controlled reflow process. Temperature profiles are monitored to prevent insufficient soldering or thermal damage.

5

Through-Hole Component Assembly

Power semiconductors, optocouplers, terminal blocks, transformers, LEDs, and other through-hole components are inserted according to the circuit design. Components are wave-soldered or manually soldered using controlled temperature and soldering time.

6

Solder Joint Inspection

Solder joints are inspected visually or through automated optical inspection. The inspection checks for insufficient solder, bridging, cold joints, component misalignment, polarity errors, and contamination.

7

Circuit Cleaning and Preliminary Testing

Flux residue and contaminants are removed where required. The assembled circuit is tested for input response, output switching, polarity, LED indication, short circuits, and basic insulation performance before encapsulation.

8

Heat Dissipation Assembly

Power devices are mounted onto aluminum heat sinks, metal bases, or thermally conductive housings. Thermal grease, insulation pads, ceramic sheets, and controlled fastening torque are used to achieve reliable heat transfer while maintaining electrical isolation.

9

Protection Circuit Installation

Depending on the model, RC snubber circuits, MOV surge protectors, transient suppression devices, over-temperature protection, or monitoring circuits are installed and verified.

10

Potting and Encapsulation

The electronic assembly is positioned inside the housing and filled with insulating epoxy or thermally conductive encapsulating material. Vacuum treatment may be used to reduce trapped air. The resin is cured under controlled temperature and time conditions.

11

Electrical Performance Testing

Each relay is tested for input trigger voltage, release voltage, input current, output leakage current, on-state voltage drop, zero-crossing characteristics, random-trigger response, insulation resistance, and dielectric strength.

12

Load and Thermal Testing

The relay is operated under a specified load to verify switching stability and heat dissipation. Case temperature, semiconductor temperature rise, terminal temperature, and output waveform are monitored during testing.

13

Burn-In and Reliability Screening

Selected models or production batches undergo continuous powered operation, repeated switching, high-temperature aging, or thermal cycling. Unstable components and early-life failures are identified before shipment.

14

Final Inspection and Packaging

Terminal torque, housing condition, labels, current ratings, control voltage markings, wiring identification, and mounting accessories are checked. Approved products receive batch codes and are packed with appropriate electrostatic and mechanical protection.

Customization & Delivery

We support the following types of customization

Electrical Parameter Customization :

Custom voltage & current, AC/DC type, zero-cross or random trigger.
Mounting Structure Customization :

Custom mounting, terminals and non-standard dimensions.
Heat Dissipation & Protection Customization :

Custom heat dissipation, high isolation, potting and anti-corrosion protection.
Function Upgrade Customization :

Overheat/overcurrent protection, anti-interference, delay and soft start optional.
Appearance & Brand Customization

Custom logo, marking, OEM/ODM and personalized solution design.

Proofing Cycle

Regular customization: 3-7 working days
Complex Customization: 7-15 working days
Urgent Sampling: 24-72 hours
Proofing Cost ( $ )

2222 US dollars
MOQ

Conventional products have no minimum order quantity. Customized products can be consulted with customer service
Delivery Time

The delivery time usually varies depending on the quantity and model of the order, usually 3-5 days. For specific times, please consult us

Frequently Asked Questions

How can I get an accurate quotation?

Please provide the product model or drawing, application, voltage and current, actuator or terminal configuration, cable requirements, expected quantity, destination market and required certifications. The more complete the information, the faster we can recommend a suitable solution and prepare an accurate quotation.
What is not covered by the warranty?

The warranty does not cover damage caused by incorrect wiring, excessive electrical load, improper installation, unauthorized modification, misuse, normal wear or operation outside the product’s specified environmental conditions. Final warranty coverage is subject to the applicable product specification and sales agreement.
What does the product warranty cover?

The warranty covers verified defects in materials or manufacturing under the specified operating and installation conditions. Depending on the case, XURUI may provide technical analysis, replacement parts, repair or product replacement in accordance with the agreed warranty terms.
What is your standard production lead time?

Lead time depends on product type, order quantity, material availability and customization requirements. Standard products generally have shorter lead times, while customized products require additional time for approval, tooling or validation. The confirmed delivery schedule will be stated in the quotation.
Which certifications and compliance documents are available?

Certifications vary by product series and target market. Applicable certificates, test reports and material compliance documents can be provided for qualified models. Please confirm the exact product number and destination market before requesting documentation.
Can you support samples and small trial orders?

Yes. We support sample orders and small trial orders for most standard products. The minimum order quantity depends on the product series, specifications and packaging requirements. Please send us the part number or application details for confirmation.
What customization services do you offer?

We provide OEM and ODM support, including actuator structures, terminals, cables, connectors, electrical ratings, housing colors, labels and packaging. Each request is reviewed for technical feasibility, tooling requirements, testing and expected order volume.
How long does custom sample development take?

Sample lead time depends on the level of customization. Changes ivolving existing components are generally faster, while new molds, special materials or additional validation require more time. A confirmed schedule will be provided after reviewing your drawings and specifications.
How are custom sample costs calculated?

Sample costs may include materials, tooling, engineering, testing and certification-related expenses. We provide a detailed quotation before development begins. Any arrangement for refunding or crediting sample fees will be stated clearly in the quotation.
How do you ensure product traceability?

Key materials, production batches, assembly records and test results are controlled through lot identification. This allows us to trace products back to relevant materials, production dates and inspection records when required.
What quality inspections are performed?

Our quality process includes incoming material inspection, in-process control, functional testing and final inspection. Product-specific checks may include operating force and travel, contact resistance, insulation resistance, dielectric strength, sealing performance, temperature rise and endurance validation.

Product model	XSSR-DA48□M4
Control voltage	3-32VDC
Control current	6-25mA
Reverse voltage	32VDC
Guarantee close voltage	1VDC
Guarantee open voltage	3VDC
Load voltage	75-480VAC
Load max current	400A-500A
Load mini current	0.3A
Breakover voltage	≤3VAC
Output leakage current	≤1mA
Medium withstand voltage	≥2500VAC
Insulating resistance	≥100MΩ
Switching time	≤10mS
Frequency range	50-60Hz
Operating temperature	-20-70℃
Load current safety factor	Resistive load 50-60%
Load current safety factor	Inductive load 30-40%