This Product Selection Guide contains information to help select products in the Safety Relays category on DigiKey.com
Products in the safety relay category include a variety of device types designed to enhance or accommodate human safety interests in some way. They include standard relay types with force-guided contacts, industrial automation safety relay products that provide for verification of contact state, and relays designed to accommodate electrical interfacing between hazardous (e.g. potentially flammable or explosive atmosphere) and non-hazardous areas within a working environment.
SelectionCharacteristics
Mounting Type: Indicates how the device is attached.
Coil Voltage: The nominal voltage that must be applied to a relay’s control coil to actuate the device.
Contact Form: Describes the contact closures provided by a relay or relay-output device, in terms of the number of independent circuits that are actuated in parallel, the number of contact positions available for each, and their default states. For more information please see Switch Basics, Examples of Pole and Throw.
Contact Rating (Current): The amount of current that a relay’s contacts are rated to interrupt when switching a resistive load. Ratings may differ for reactive loads and when switching AC or DC current.
Switching Voltage: The voltage that a relay’s output contacts are rated to interrupt.
Features: These are different capabilities or properties of the device such as a diode or lighted indicator.
Termination Style: Selection of termination style used to connect the device to a system, such as PC pins or screw terminals.
Must Operate Voltage: The minimum voltage needed to energize the coil.
Must Release Voltage: The maximum applied voltage at which a relay must return to an inactive state.
Operate Time: Characterizes the time delay between the application of rated coil voltage and the closure (or opening) of all contacts that occurs as a result. Typically does not include contact bounce time.
Release Time: Characterizes the time delay between the removal of power from the device coil and all contacts returning to their rest positions. Does not include bounce time, and may be affected by the choice of control circuitry.
Operating Temperature: Recommended operating temperature, typically given in a range or as a maximum. Exceeding these temperatures may affect performance or damage the device and other system components.
ProductExamples
| MFR PART # | V23050-A1024-A542 |
|---|---|
| DIGI-KEY PART # | PB664-ND |
| MANUFACTURER | TE Connectivity Potter & Brumfield Relays |
| DESCRIPTION | Component Mount TO-18 Circular 0.060" (1.52mm) White |
| DATASHEET | Click Here |
| MFR PART # | SR-IM-9A |
|---|---|
| DIGI-KEY PART # | 2170-SR-IM-9A-ND |
| MANUFACTURER | Banner Engineering Corporation |
| DESCRIPTION | Component Mount TO-18 Circular 0.060" (1.52mm) White |
| DATASHEET | Click Here |
| MFR PART # | SFS4-L-DC24V-D |
|---|---|
| DIGI-KEY PART # | 255-5358-ND |
| MANUFACTURER | Panasonic Electric Works |
| DESCRIPTION | Component Mount TO-18 Circular 0.060" (1.52mm) White |
| DATASHEET | Click Here |
SchematicSymbol
Schematic symbol courtesy of Scheme-it. Please see their website for more information and symbols.
MediaLinks
Videos
How to Choose a Relay - Another Teaching Moment | DigiKey Electronics
Relay Basics - Another Teaching Moment | DigiKey Electronics
TechForum
Phoenix Contact Relay / input voltage confusion!