KSD240D3-W (037) Solid State Relay, 4-32VDC Input, 240VAC 3A Zero-Cross SSR

The KSD240D3-W (037) Solid State Relay is a compact, high-reliability switching device designed for efficient control of AC loads in industrial, commercial, and automation environments. Built using solid-state semiconductor technology, it provides silent operation, long service life, and fast, maintenance-free switching compared to traditional electromechanical relays.

This model features a wide input control voltage range of 4VDC to 32VDC, making it highly flexible for integration with PLC systems, microcontrollers, industrial controllers, and various low-voltage control circuits. The relay requires a maximum input current of just 20mA, ensuring energy-efficient operation and compatibility with a broad range of control outputs.

On the output side, the KSD240D3-W is designed for AC load switching in the 48VAC to 280VAC range, with a nominal 240VAC rating. It supports continuous load currents from 0.1A up to 3A, making it suitable for medium-duty AC switching applications such as heaters, lamps, and small motors.

The relay uses zero-cross switching technology, meaning it only activates when the AC waveform crosses zero voltage. This significantly reduces electrical noise, minimizes electromagnetic interference (EMI), and reduces inrush current stress on connected loads, improving both system stability and component lifespan.

It also features strong protective characteristics, including a transient overvoltage rating of 600V peak and a dielectric isolation strength of at least 4000Vrms between input and output. These safety features ensure reliable operation in electrically noisy and industrial environments.

With fast switching performance, the KSD240D3-W offers a maximum turn-on and turn-off time of half an AC cycle plus 1ms. Its fully solid-state construction eliminates mechanical wear, arcing, and contact bounce, ensuring long-term durability even in high-frequency switching applications.

Features

• Solid State Relay (SSR) for AC load control
• Wide 4-32VDC input control range
• 240VAC class output (48-280VAC operating range)
• 3A maximum load current
• Zero-cross switching for reduced EMI and inrush current
• High surge capability up to 120A (10ms)
• 600V peak transient overvoltage protection
• 4000Vrms input-output dielectric isolation
• Fast switching response ( AC cycle + 1ms)
• Silent, arc-free operation
• High reliability with no mechanical wear
• Low input current (max 20mA)

Specifications

• Model: KSD240D3-W (037)
• Device Type: Solid State Relay (SSR)
• Control Voltage: 4-32VDC
• Maximum Input Current: 20mA
• Minimum Turn-On Voltage: 4VDC
• Minimum Turn-Off Voltage: 1VDC
• Load Voltage Range: 48-280VAC
• Nominal Load Voltage: 240VAC class
• Output Type: Zero-Cross Switching
• Load Current Range: 0.1-3A
• Maximum Surge Current (10ms): 120A
• Transient Overvoltage: 600V peak
• Turn-On Time: 1/2 AC cycle + 1ms
• Turn-Off Time: 1/2 AC cycle + 1ms
• Dielectric Strength: 4000Vrms (Input to Output)

Applications

• Industrial automation and control panels
• HVAC and temperature control systems
• Lighting control systems
• PLC-based switching systems
• Motor and fan control (light duty)
• Heating element control
• Building automation systems
• Packaging and production machinery
• General-purpose AC load switching
• Energy-efficient switching systems

What's in the box
1 x KSD240D3-W (037) Solid State Relay, 4-32VDC Input, 240VAC 3A Zero-Cross SSR