4 output dc solid state relay

I. Product Overview and Series

This document introduces GREEGOO's series of Four-Channel DC Solid State Relays, which are characterized by their modular design​ and contactless switching technology.

The product line consists of three main model types:

• GZ042KB / GZ042KBL: Two Normally Open (2NO) Two Normally Closed (2NC)​ hybrid output type.

• GZ044B / GZ044BL: Four Normally Closed (4NC)​ output type.

• GZ044K / GZ044KL: Four Normally Open (4NO)​ output type.

(Note: Models with the suffix "L" feature built-in overcurrent protection (e.g., GZ044KL). Models without the "L" lack this function and require an external fast-acting circuit breaker.)

II. Core Features and Advantages

1. High Integration: A single module integrates four independent control channels, simplifying the design of multi-channel control systems.

2. Safety Isolation: Features opto-coupler and magnetic coupling isolation​ between input and output circuits, with an isolation voltage rating of up to 1500-2500V, ensuring control-side safety.

3. Strong Compatibility: Control signals are compatible with PLC​ and TTL logic interfaces, facilitating easy integration into industrial control systems.

4. High Reliability: Encapsulated in epoxy resin for corrosion resistance and shock resistance. The contactless switching is spark-free and arc-less, ensuring a long operational life.

5. Fast Response: Extremely short switching time (≤0.18ms), suitable for applications requiring high-speed switching.

III. Key Electrical Parameters

IV. Typical Application Scenarios

These products are primarily used for multi-channel control of DC power supply equipment, such as:

• Control of DC heaters, solenoid valves, and DC motors.

• New energy equipment, such as power switching and management in charging/discharging systems.

V. Selection and Safety Usage Guidelines

1. Current Rating Selection: A sufficient safety margin must be allowed based on the load nature.

   • Resistive Loads​ (e.g., heating elements): Select a rated current 2-4 times​ the load current.

   • Inductive Loads​ (e.g., motors, solenoids): Select a rated current 3-6 times​ the load current.

2. Heat Dissipation Management: A heat sink is mandatory (for currents ≥10A). For high power (≥50A), forced air cooling is required. During installation, apply thermal conductive silicone grease to ensure a flat contact surface and tighten screws symmetrically.

3. Essential Protection Measures:

   • For inductive loads, a freewheeling diode must be connected in parallel across the load, and a varistor (MOV) should be connected at the output terminals​ to absorb back-EMF and surge voltages.

   • If selecting a model without overcurrent protection​ (e.g., GZ044K), a fast-acting circuit breaker must be connected in series within the load circuit​ to prevent short-circuit damage.

4. Power-Up Sequence: The main power supply and control power supply must be energized first. The load current is then switched via the ON/OFF state of the control signal.