The SSR-40AA Solid State Relay is a single-phase electronic switching device designed to control AC electrical loads using an AC control signal.
Featuring a 40A rated load current, 80–250V AC control input, and 24–380V AC output, this relay provides silent, reliable switching without mechanical contacts.
It is suitable for industrial automation, heating systems, lighting control, and electrical control panels.
Key Features
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40A Rated Load Current: Designed for switching compatible AC loads.
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AC-to-AC Operation: Controls AC loads using an AC input signal.
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80–250V AC Control Input: Suitable for compatible AC control circuits.
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24–380V AC Load Output: Supports a wide range of AC applications.
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Silent Switching: No mechanical clicking or moving contacts.
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Solid-State Design: Eliminates mechanical contact wear.
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Compact Construction: Suitable for electrical panels and automation systems.
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Screw Terminal Connections: Convenient installation and wiring.
Technical Specifications
| Parameter |
Specification |
| Model |
SSR-40AA |
| Product Type |
AC-to-AC Solid State Relay |
| Rated Load Current |
40A |
| Control Input Voltage |
80–250V AC |
| Load Output Voltage |
24–380V AC |
| Switching Type |
Solid-State AC Switching |
| Phase |
Single Phase |
| Terminal Type |
Screw Terminals |
| Mounting Type |
Panel Mount |
| Cooling |
External Heatsink Required for High Loads |
Terminal Configuration
| Terminal |
Function |
| 1 |
AC Load Terminal |
| 2 |
AC Load Terminal |
| 3 |
AC Control Input |
| 4 |
AC Control Input |
Note: Always follow the terminal markings printed on the relay housing.
Applications
- Industrial Automation
- AC Heating Systems
- Temperature Control Systems
- AC Lighting Control
- Electrical Control Panels
- Industrial Equipment Switching
- Automated AC Load Control
Important Notes
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AC-to-AC Relay: Designed for AC control signals and AC loads only.
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Not Directly GPIO Compatible: Cannot be controlled directly from Arduino, ESP32, or Raspberry Pi GPIO. A suitable isolated AC control interface is required.
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Heatsink Required: Use an appropriately sized heatsink and thermal compound, especially when operating at higher currents.
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40A Maximum Rating: Actual continuous current capacity depends on cooling, ambient temperature, and load characteristics.
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Inductive Loads: Motors and transformers may require additional derating and surge protection.
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Electrical Safety: Installation should be performed by qualified personnel.
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Off-State Leakage: Solid-state relays may allow a small leakage current even when switched off.
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Not a Circuit Breaker: Appropriate overcurrent protection must be installed separately.
Package Includes
