This Product Selection Guide contains information to help select products in the Power Relays, Over 2 Amps category on DigiKey.com
Power Relays over 2 Amps are electromechanical device that turns a large load on or off through the use of a smaller control signal.
Selection Characteristics
Mounting Type: Indicates how the device is physically attached.
Coil Voltage: The nominal voltage that must be applied to a relay’s control coil to actuate the device. Observe that the coil voltage is specified as either AC or DC. This distinction is paramount as a coil designed for DC operation will not activate when an AC signal is applied to the coil.
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.
Coil Current: The nominal current flow through a relay’s control coil when the indicated coil voltage is applied.
Coil Type: Whether the coil is latching or non-latching, single or dual coil.
Features: These are different capabilities or properties of the device such as a diode, lighted indicator, or test button.
Termination Style: Selection of termination style used to connect the device to a system, such as PC pins, socketable, or wire leads.
Seal Rating: Defines what type of sealing is on the relay.
Coil Insulation: The class of insulation the relay is built to meet. For more information please see Transformer Insulation Class
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.
Contact Material: The material used for the electrical contacts on the relay.
Relay Type: Indicates a relay’s internal operating mechanism, typical usage, or other distinguishing feature.
Product Examples
| MFR PART # | 34.51.7.024.0010 |
|---|---|
| DIGI-KEY PART # | 2066-34.51.7.024.0010-ND |
| MANUFACTURER | Finder Relays, Inc. |
| DESCRIPTION | Component Mount TO-18 Circular 0.060" (1.52mm) White |
| DATASHEET | Click Here |
| MFR PART # | G2R-1A-T DC12 |
|---|---|
| DIGI-KEY PART # | Z2918-ND |
| MANUFACTURER | Omron Automation and Safety |
| DESCRIPTION | Component Mount TO-18 Circular 0.060" (1.52mm) White |
| DATASHEET | Click Here |
| MFR PART # | RTD14005 |
|---|---|
| DIGI-KEY PART # | PB979-ND |
| MANUFACTURER | TE Connectivity Potter & Brumfield Relays |
| DESCRIPTION | Component Mount TO-18 Circular 0.060" (1.52mm) White |
| DATASHEET | Click Here |
Schematic Symbol
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
Relay Basics - Another Teaching Moment | DigiKey Electronics | DigiKey
TechForum
Phoenix Contact Relay/input voltage confusion!
Understanding Relay Coil Voltage Specifications