Central Processing Unit PM861AK01

Central Processing Unit PM861AK01

Central Processing Unit PM861AK01

TRSOTF

This is the signal “Trip by Switch Onto Fault”. It is usually connected to the “switch onto fault” output of line protection if multi-shot Auto-Reclose attempts are used. The input will start the shots 2-5.

THOLHOLD

Signal “Thermal overload protection holding back Auto-Reclosing”. It can be connected to a thermal overload protection trip signal which resets only when the thermal content has fallen to an acceptable level, for example, 70%. As long as the signal is high, indicating that the line is hot, the Auto-Reclosing is held back. When the signal resets, a reclosing cycle will continue. Please observe that this have a considerable delay. Input can also be used for other purposes if for some reason the Auto-Reclose shot need to be halted.

TR2P and TR3P

Signals for two-phase and three-phase trip. They are usually connected to the corresponding output of the TRIP block. They control the choice of dead time and the reclosing cycle according to the selected program. Signal TR2P needs to be connected only if the trip has been selected to give 1/2/3 phase trip and an auto reclosing cycle with two phase reclosing is foreseen.

WAIT

Used to hold back reclosing of the “low priority unit” during sequential reclosing. See “Recommendation for multi-breaker arrangement” below. The signal is activated from output WFMASTER on the second breaker Auto-Recloser in multi-breaker arrangements