Main computer board PM510V16

Main computer board PM510V16

Main computer board PM510V16

The four step residual overcurrent protection EF4PTOC is used in several applications in the power system. Some applications are:

• Earth-fault protection of feeders in effectively earthed distribution and subtransmission systems. Normally these feeders have radial structure.

• Back-up earth-fault protection of transmission lines.

• Sensitive earth-fault protection of transmission lines. EF4PTOC can have better sensitivity to detect resistive phase-to-earth-faults compared to distance protection.

• Back-up earth-fault protection of power transformers.

• Earth-fault protection of different kinds of equipment connected to the power system such as shunt capacitor banks, shunt reactors and others. In many applications several steps with different current operating levels and time delays are needed. EF4PTOC can have up to four, individual settable steps. The flexibility of each step of EF4PTOC is great.

The following options are possible: Non-directional/Directional function: In some applications the non-directional functionality is used. This is mostly the case when no fault current can be fed from the protected object itself. In order to achieve both selectivity and fast fault clearance, the directional function can be necessary. This can be the case for earth-fault protection in meshed and effectively earthed transmission systems.