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Greegoo Electric offers worldwide shipping, delivering our high-quality electrical components to over 50 countries via trusted logistics partners like DHL, air freight, or sea freight, ensuring fast, secure, and cost-effective delivery tailored to your needs.

At Greegoo Electric, we deliver world-class electrical solutions through our specialized facilities across China. Yueqing, Zhejiang: Our cutting-edge factory produces reliable solid state relays, circuit breakers and switches for industrial needs. Wenzhou, Zhejiang: Our dedicated import-export hub connects global markets with premium electrical components. Yidu, Hubei: Our advanced manufacturing center crafts medium-voltage switchgears for robust power systems. Shenzhen: Our R&D powerhouse drives innovation in electrical technology design. Jiangsu: Our specialized plant delivers high-performance power semiconductors.

The DC Motor Reversing Solid State Relay is a contactless electronic switching device specifically designed to control the forward and reverse operation of DC motors. It utilizes two internally reverse-parallel MOSFET or IGBT sets to switch the motor phase sequence, thereby controlling the motor's forward and reverse rotation. Compared to traditional mechanical contactor-based solutions, it eliminates arcing, noise, and mechanical wear, offering higher reliability, faster response times, and longer service life.

The Motor Forward and Reverse Solid State Relay is a contactless electronic switching device specifically designed to control the forward and reverse operation of three-phase AC motors. It utilizes two internally reverse-parallel thyristor or MOSFET sets to switch the motor phase sequence, thereby controlling the motor's forward and reverse rotation. Compared to traditional mechanical contactor-based solutions, it eliminates arcing, noise, and mechanical wear, offering higher reliability, faster response times, and longer service life.

Three-Phase Solid State Relay (SSR) is a contactless electronic switching device used to control the on/off operation of three-phase AC loads. It utilizes semiconductor components (such as thyristors, MOSFETs, etc.) as switching elements, enabling the control of high-voltage, high-current three-phase AC circuits through low-voltage DC of 4-32V or AC of 90-280V signals.

Three-phase solid-state relays offer significant advantages such as being contactless, fast response, long lifespan, and strong anti-interference capabilities, making them particularly suitable for industrial motor control, electric heating systems, automation equipment, and other applications that require frequent, reliable switching and resilience in harsh environments.

A single-phase solid-state relay (SSR) is an electronic switching device that uses semiconductor components (such as triacs or SCR) to control power to a load in a single-phase AC circuit. Unlike traditional electromechanical relays, it has no moving parts, which allows it to operate silently and last for millions of cycles without physical wear. 

• Zero-Cross Switching: Turns on only when the AC voltage waveform crosses the zero-volt line. This is ideal for resistive loads like heaters because it minimizes electrical noise (EMI).
  
  
• Random (Instant-On) Switching: Switches immediately upon receiving the control signal. This is necessary for inductive loads (like motors) or applications requiring precise timing.

The main difference lies in their internal circuit configuration: MTC is connected in series (half-bridge), MTK shares a common cathode, MTA shares a common anode, and MTX is connected in anti-parallel for AC switching. These modules all feature an electrically isolated baseplate, standard industrial packaging, and high-voltage insulation designed for efficient heat dissipation and simplified mounting in power electronic systems.

The MDK common-cathode module internally connects the cathodes of the switching transistor and the freewheeling diode together, which precisely matches the topology of the Boost converter circuit in photovoltaic inverters. This design allows a single module to replace two discrete devices, eliminating complex external wiring. This results in a more compact circuit, better heat dissipation, and higher reliability, perfectly meeting the demands of photovoltaic inverters for high power density and long-term stable operation.

Greegoo's low voltage drop solid state relay is engineered for complete elimination of heat sinks. With its revolutionary ultra-low conduction voltage drop (<0.1V), it dissipates less than 3W at a 30A load—over 90% lower than conventional solutions (30-45W)—fundamentally eradicating thermal challenges. This means: no bulky heatsinks, saving 60-80% space; no forced-air cooling, enabling unrestricted mounting; no ventilation cutouts, preserving enclosure integrity; and no complex thermal simulations, simplifying system design. It is the ideal solution for space- and thermally-constrained applications such as compact devices, sealed cabinets, and high-density installations, delivering truly miniaturized, highly reliable DC control.

A margin should be left when selecting the voltage and current of the solid state relay.

For resistive load: the current is selected according to 2.5~4 times the load current, and the voltage is selected according to 2~2.5 times the load power. Inductive load: current is selected according to 3-7 times load current, voltage is selected according to 2.5-3 times load voltage.

According to the relationship between load current and ambient temperature, when the ambient temperature is high or heat dissipation conditions are not good, the current capacity of the solid state relay should be increased accordingly.
In order to prevent the product from short-circuiting during use, it is necessary to connect a fast circuit breaker or a fast fuse in series with the product in the load circuit.

For inductive loads, a freewheeling diode must be connected to both ends of the load, and a varistor must be connected to the output end (the varistor (MOV) is selected according to 1~1.5 times of the power supply voltage) to prevent the high voltage generated during switching from damaging the solid-state switch.

When the product is installed, it is required that the contact surface between the heatsink and the product must be flat and clean, and a layer of thermally conductive silicone grease is applied to its surface, and then finally the screws set with flat washers and Spring washersare tightened symmetrically to fix.