Protection Relays

Protection relays are devices that monitor quantities such as current, voltage, phase sequence and temperature and, when a set limit is exceeded, have the circuit tripped through the output contact. They are used on motor feeders, in pump and compressor panels, at mains and generator incomers and in distribution cells to isolate the faulty section from the circuit before damage grows. In addition to the current, voltage, phase and motor protection relay subgroups, this category includes ABB Ekip UP digital protection units, distribution automation relays such as the REX615, TVOC-2 arc protection equipment and Siemens protection relays; ABB, Tense, Siemens and Entes are the predominant brands. Choose the quantity to be monitored, the measuring method (direct or through a current transformer), the supply voltage, the setting and delay range and the number of output contacts according to your protection scheme. In projects that require communication, verify protocol support such as IEC 61850 from the standard information on the product page. In most applications, a protection relay does not interrupt the fault current itself; it gives the trip command to the contactor or to the circuit breaker's shunt trip coil.

Products

How to choose Protection Relays

Protection relays are devices that monitor quantities such as current, voltage, phase sequence and temperature and, when a set limit is exceeded, have the circuit tripped through the output contact. They are used on motor feeders, in pump and compressor panels, at mains and generator incomers and in distribution cells to isolate the faulty section from the circuit before damage grows.

  • Separate overcurrent/leakage protection, motor starting and local isolation requirements.
  • Select rated current, pole count and breaking capacity (kA) from the installation calculation.
  • Match coil voltage, auxiliary contacts and tripping curve to the control circuit and load type.

Frequently asked questions

What is Protection Relays and where is it used?

Protection relays are devices that monitor quantities such as current, voltage, phase sequence and temperature and, when a set limit is exceeded, have the circuit tripped through the output contact. They are used on motor feeders, in pump and compressor panels, at mains and generator incomers and in distribution cells to isolate the faulty section from the circuit before damage grows.

What should I compare when choosing Protection Relays?

Choose the quantity to be monitored, the measuring method (direct or through a current transformer), the supply voltage, the setting and delay range and the number of output contacts according to your protection scheme.

Which product groups are available under Protection Relays?

The current subcategories include Current Protection Relays, Overcurrent Secondary Protection Relays, Phase and Motor Protection Relays, Phase Sequence Protection Relays, Thermistor Relays, Voltage Protection Relays. Open a subcategory to compare its products and technical details.

What Is a Phase Protection Relay? Selection Guide