QERP 408 - reactive power controller

Description and use: the QERP 408 and 416

 is designed to compensate reactive loads of inductive nature. It is connected to pulse meters for active and reactive consumption or reactive supply. Active parallel inputs 1 to 4 are used to connect the pulse meters.These 4 parallel inputs are active and are not galvanically isolated from each other. The maximum impedance of the parallel inputs is 500 Ohms. The serial line is adapted for connection to a 1/4 hour maxima HMP 64M control system. The function of the parallel inputs and the RS 485 line is indicated by illuminated LEDs. The outputs of the controller consist of 5A/250VAC relay switch contacts. The number of outputs can be set from 1 to 16 stages. The outputs can be programmed for inductive load-switching capacitance compensation or for capacitive supply-switching inductance compensation. The values of the individual stages are entered in the basic settings of the controller. The control bandwidth can be selected in the range cos ϕ 0.872-1 with selectable upper and lower limits for the value of the insensitivity bandwidth. Furthermore, the speed of the control during undercompensation and overcompensation and the dependence of the control time shortening can be selected. The instrument is supplied in a 144x144 IncaBox for mounting on the front of the rack. All data is displayed on a 128x64 dot graphic LCD display. There is also a control keypad and LEDs on the front panel to indicate parallel inputs and serial lines. 

Specifications:

The controller is equipped with 8 or 16 5A/250VAC output switching relays. 
The controller also has a 485 interface input.
230V~/50Hz power supply. 
Power input: 6 VA 
IP 40 protection 
External dimensions: INCABOX 144 x 144 x 75 mm

Function Description:

 The controller regulates by means of the so-called fast approximation, i.e. if the power factor is outside the set insensitivity band for more than the set time (regulation speed), the controller calculates a new connection of the outputs according to their values, so that the power factor reaches the middle of the band, which can be set asymmetrically, and this connection of the outputs is gradually realized. The controller also has built-in statistics from which it is possible to determine the number of switching of individual stages and other data see below.