1398.0 Advanced AdjustmentsThere are additional US parameters which can provide further functional adjustmentsof the drive. These US parameters are all those greater than US.10. The followingwill provide a basic description of the function of each parameter.The E.OL2 function is designed to protect the inverter from dangerous currents whenoperating at very low output frequencies. With some geared motors and mainly withgearless motors the drive is forced to provide high currents at output frequenciesbelow 3 Hz. This causes considerable thermal loading on the power transistors. Inan attempt to protect itself the drive will monitor the load current when operatingbelow 3 Hz. If the safe value is exceeded, the drive will trigger the error E.OL2. Seesection 2.7 for a table with the actual current values. A value of 0 in US.16 providesthis function.A value of 16 takes into consideration the actual temperature of the power modules.If the temperature is lower, the threshold level for the output current is raised allowingmore current to flow before triggering the error.A value of 64 will cause the drive to automatically lower the carrier frequency whenthe output current reaches the E.OL2 limit. By doing so the actual threshold valueis raised preventing E.OL2 and the drive keeps running. It is possible that undercertain cases the carrier frequency might become low enough to be audible.0 = Standard function E.OL2 at listed current values16 = Heatsink temperature dependent E.OL264 = Auto carrier frequency reduction80 = both temp dependent and auto carrier freq. reductionUS. 16E.OL2 functionAdvanced Parameters
