ABB REF615 L User Manual

A070972 V3 EN
Figure 310: Incorrect connection of trip-circuit supervision
A connection of three protection IEDs with a double pole trip circuit is shown in
the following figure. Only the IED R3 has an internal TCS circuit. In order to test
the operation of the IED R2, but not to trip the circuit breaker, the upper trip
contact of the IED R2 is disconnected, as shown in the figure, while the lower
contact is still connected. When the IED R2 operates, the coil current starts to flow
through the internal resistor of the IED R3 and the resistor burns immediately. As
proven with the previous examples, both trip contacts must operate together.
Attention should also be paid for correct usage of the trip-circuit supervision while,
for example, testing the IED.
Section 6 1YHT530004D05 D
Supervision functions
578 615 series
Technical Manual

ABB REF615 L Specifications

General

Type	Feeder Protection Relay
Rated Frequency	50/60 Hz
Weight	Approx. 1.5 kg
Communication Protocols	IEC 61850, Modbus RTU, DNP3
Protection Functions	Overcurrent, Earth fault, Thermal overload, Under/Over voltage, Under/Over frequency
Enclosure	IP20