Accumulation of the I yt module calculates the accumulated energy.
The operation of the module can be described with a module diagram. All the modules in the diagram are explained in the next sections.
Accumulated energy calculator
This module calculates the accumulated energy I yt [(kA) ys]. The factor y is set with the Current exponent setting.
The calculation is initiated with the POSCLOSE input opening events. It ends when the RMS current becomes lower than the Acc stop current setting value.
The Difference Cor time setting is used instead of the auxiliary contact to accumulate the energy from the time the main contact opens. If the setting is positive, the calculation of energy starts after the auxiliary contact has opened and when the delay is equal to the value set with the Difference Cor time setting. When the setting is negative, the calculation starts in advance by the correction time before the auxiliary contact opens.
The accumulated energy outputs IPOW_A (_B, _C) are available in the monitored data view on the LHMI or through tools via communications. The values can be reset by setting the parameter SSCBR1 acc.energy setting to true in the Clear menu from LHMI.
Alarm limit check
The IPOW_ALM alarm is activated when the accumulated energy exceeds the value set with the Alm Acc currents Pwr threshold setting. However, when the energy exceeds the limit value set with the LO Acc currents Pwr threshold setting, the IPOW_LO output is activated.
The IPOW_ALM and IPOW_LO outputs can be blocked by activating the binary input BLOCK.