The TFJA-07 type reactive power corrector has full automatic operation and does not have any buttons on the front panel. The interference is happening according to phase voltage and current in one phase. The device switches on the five capacitor groups in five steps by microcontroller based rating algorithm with contactors if the cos ϕ value is less, than 0,95, and switches off the capacitors, when the cos ϕ value is more, than 1. The switch on of capacitor groups happening with 14 seconds, the switch off happens with 5 seconds time delay. In load free or less load state, where cos ϕ value is not between 0,95 and 1, the first capacitor level works as a  joker capacitor; it switches on/off the capacitors according to defined delay time. The lowest capacitor power group has to be connected to the first level. During rating process the switching of the levels are happening by a complex algorithm protecting the capacitor groups and the switching contactors from run-down. The power factor value is readable from 3 digits front plate display. The front panel LED-s are giving information from number of switched levels and the power ratio’s style. The capacitor group’s power and the distributions for levels can be making by next table.

Input of voltage meter:          L1, N
Sampling:                           64 sample/period
Input of current meter:          k, l
Max. load of current input:    max. 7 A constant, 20 A / for 1 sec.
Contact / alarm output:        250 V/5 A AC