This Product Selection Guide contains information to help select products in the Protection Relays & Systems category on DigiKey.com
Protection relays detect abnormal operating conditions in an industrial system and may trigger an alert or isolate the offending device from the system. Common detection functions include; Arc-flash, temperature monitoring, ground fault, over-current, over-voltage, reverse power flow, over-frequency, under-frequency and phase loss, sequence or imbalance.
SelectionCharacteristics
Function: Indicates the style and configuration of the device.
Voltage - Supply: Typically represented by a range, this indicates the low and high voltage limits which one can expect standard operation. Voltages outside this range may damage the device and other system components.
Trip Range: Indicates the range over which a device’s monitoring threshold can be adjusted.
Delay Time: Describes a fixed or adjustable period of time after a monitored circuit exceeds some defined threshold that a device will wait before actuating its output.
Mounting Type: Indicates how the device is attached.
Termination Style: Selection of termination style used to connect the device to a system, such as screw terminals or wire leads.
Features: These are different capabilities or properties of the device such as an automatic reset or test button.
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 # | 3RN20101CW30 |
|---|---|
| DIGIKEY PART # | 3473-3RN20101CW30-ND |
| MANUFACTURER | Siemens |
| DESCRIPTION | THERMISTOR MOT. PROT. 1NO 1NC BI |
| DATASHEET | Click Here |
| MFR PART # | 777-P2 |
|---|---|
| DIGIKEY PART # | F10492-ND |
| MANUFACTURER | Littelfuse Inc. |
| DESCRIPTION | 3-PHASE OLR/200-480V/2-800FLA+ |
| DATASHEET | Click Here |
| MFR PART # | SE-330AU-00-00 |
|---|---|
| DIGIKEY PART # | 18-SE-330AU-00-00-ND |
| MANUFACTURER | Littelfuse Inc. |
| DESCRIPTION | NEUTRAL-EARTHING-RESISTOR MONITO |
| DATASHEET | Click Here |
| MFR PART # | DEA71DM24A003 |
|---|---|
| DIGIKEY PART # | 1864-2893-ND |
| MANUFACTURER | Carlo Gavazzi Inc. |
| DESCRIPTION | EARTH LEAKAGE MONITORING RELAY |
| DATASHEET | Click Here |