Safety relays and normal relays are distinct devices designed for different applications and with specific characteristics. Here are the key differences between them:
| specific characteristics | Safety Relay | Normal Relay |
|---|---|---|
| Functions | Safety relays include various functions such as switching, indication, and protection. They are designed to continuously monitor hazardous processes and detect even minor irregularities to ensure safety. | Normal relays are mainly used for basic switching and may not have the extensive protective and monitoring features of safety relays |
| Function and Application | A safety relay is primarily used to implement security functions. It is designed to ensure the safety of individuals and machinery by monitoring and controlling safety-critical processes. Safety relays are used in applications where failure could lead to harm or injury, such as emergency stop systems, safety gates, and safety light curtains | A normal relay, also known as a general or common relay, is an electrically operated switch used for controlling a high-power circuit with a low-power signal. It is commonly employed in control circuits for various purposes, such as switching loads, signaling, and automation |
| Size | Safety relays tend to be larger in size compared to normal relays. Their larger dimensions are due to the advanced circuitry and components required to ensure safety functions. | Normal relays come in smaller sizes as they are primarily used for basic switching within control circuits. Their compact design is suitable for general control applications. |
| Contact Structure | Safety relays are equipped with force-guided contacts, including locked, positive, or captive-guided contacts. These contacts ensure that the relay operates reliably, especially in the event of contact welding or fusion. The design is focused on minimizing the risk of contact failure. | Normal relays typically employ electrically conductive metal contacts for basic switching operations. They lack the force-guided contacts found in safety relays. |
| Color | Safety relays are often designed in a specific color, typically yellow. This distinctive color makes them easily recognizable and helps identify their role in safety applications. | Normal relays are not typically associated with a specific color and are often found in standard colors like white. |
| Dimensions | Safety relays have larger dimensions, such as 17.5 mm, 22.5 mm, etc., to accommodate the necessary safety features and circuitry. | Normal relays have smaller dimensions, making them more compact and suitable for general control applications. |
| Cost | Safety relays are generally more expensive than normal relays due to their specialized safety functions and additional features. | Normal relays are typically more cost-effective as they are used in a wide range of general control and switching applications |
| Applications | Safety relays are commonly used in safety-critical applications where the protection of individuals and machinery is paramount. They are essential for ensuring compliance with safety standards and regulations | Normal relays find their application in a broad spectrum of automation and control systems, where safety considerations are not the primary focus. |
- safety relays and normal relays differ in terms of their size, contact structure, color, dimensions, functions, cost, and application.
- Safety relays are specialized for safety-critical applications and come with enhanced safety features, while normal relays are versatile devices used for general control and switching tasks.
- Understanding the distinctions between these two types of relays is crucial for selecting the appropriate relay for a given application.