HJ

Maximum current controllers are designed for current demand limitation so the current will not exceed the main circuit breaker level. By disconnection of appropriate loads (direct electric heaters, hot water storage cylinder etc.) protects MCB against action and lower reserved power input level. HJ controller equalizes current loading and brings savings to user by reduction of reserved power input according MCB nominal current level.

Function

Current in all three measured phases is digitalized and from measured values is by DFT (Discrete Fourier Transformation) calculated effective current value. If this value is higher than set value, measurement is repeated and if also new value is higher, stage No. 1 is disconnected. Next measurement the fall of current after stage No. 1 disconnection determines and value is saved. If the value of measured current is still higher than set value, after 3 seconds the stage No. 2 is disconnected too and fall of current is captured and saved. Reconnection of appropriate stage is realized in the case that measured current value minus fall of current of the stage increased by 1 A is less than set current maximum. If more than one stage was disconnected, preference is given to the first disconnected stage. If it is not possible, another stage is checked.

Application

hj103HJ1xx range

Current controller for application with majority of three-phase appliances such as hot water cylinder, electric boiler etc.

Current limiter HJ

Main features

  • Direct current measurement up to 100 A
  • Indirect current measurement via CT ../5A
  • Reaction suppression on short circuits and current transients
  • DFT (Discrete Fourier Transformation) signal processing