Signal amplifier GENERAL CHARACTERISTICS The VNR21.22 control units are designed as interface for conductive level probes SL series. These electronic units are used to control liquids that have a minimum electrical conductivity of 1 pS. The system is based on measurement of the conductivity of the liquid to be controlled and works with low potential and with alternating currents, in order to avoid the incrustation of the electrodes and / or perforation of the tank normally caused by the use of direct currents, which cause a galvanic action on materials. The contact of the electrode with the liquid under control determines the actuation of a relay inside the control unit and it is possible to drive any alarm system and / or actuator. By using multiple probes and multiple control units, appropriately connected, a system of dosage and safety can be realized. One channel (2100) or two channels (2200) design. Adjustable sensitivity from lpS. Relay output. Alarm led. DIN rail mounting. Description Power supply Power consumption Input signal Power supply to probes Output relay Alarm display Sensitivity range Sensitivity adjustment Operating ambient temperature Housing — Mounting Degree of protection Dimensions (mm) Electrical connection IP 40 55 x 75 x 110 10 poles terminal board 2 channels VNR.2200 24 / 230 Vac - 50/60 Hz 10 VA From conductive probes (SL series) 22 Vac 2 x SPDT — 230Vac — 6A Front panel led (2x) 10 -250 pS Front panel trimmer (2x) -20° * +50° C ABS DIN rail IP 40 55 x 75 x 110 20 poles terminal board DIMENSIONS TYPICAL WIRING MIN./MAX. LEVEL _ALARM AUTO FILL-UP CONTROL AND ADJUSTMENT Control. Disconnect the electrodes leads from the terminal board (terminals 1 and 3 for single channel version) (terminals 1-11 and 3-13 for two-channel version). Short circuit terminals 1 and 3 (11 and 13) of the terminal board, in these conditions, the relay must switch on and led has to light. Sensitivity adjustment. The unit is supplied with a factory setting of 20 pS. Submerge the electrodes in the liquid under control, turn the trimmer on the front panel to obtain the switching of the relay. One or two channels amplifier Sensitivity Power supply We reserve the right to change the data without notice Ebctonk www.valco.it