Netafim Alex-Tronix Backflush Controller, 2 Station, 24VAC/12VDC Outputs (F2AC/DC-D)

Netafim Alex-Tronix Backflush Controller for Two-Tank Filter Stations

A pair of screen, disc or media filters only protects the drip system if they are flushed before they clog. This Alex-Tronix model F2AC/DC-D, built in the U.S.A. and supplied through Netafim, automates that job for a two-tank station. It runs 2 stations plus a master valve, washing the tanks one after the other. A flush can start on a timer, on a pressure differential signal, or from the manual start button. The periodic dial sets the interval from 1/4 hour to 24 hours, or off. Flush time per tank is set from 2 to 180 seconds, and the dwell between tanks from 0 to 90 seconds. A 1-15 psi Murphy pressure differential gauge and its mounting bracket come with the controller. Power comes from 115 VAC through the standard transformer, a 240 VAC transformer option, or 12-15 VDC from a battery. Outputs drive 24VAC or 12VDC non-latching solenoids, with the output switch on the rear of the panel. The electronics sit in a rust-proof plastic outdoor enclosure measuring about 9-3/4 x 8 x 4 in.

Setting Up a Filter Backwash Controller at the Head

Mount the controller near the filter manifold, and fit the PD gauge on its bracket under the enclosure or on the manifold itself. Tube the high port to the filter outlet and the low port to the inlet, holding each threaded port with a wrench. Take the backwash time per tank from the filter maker, and set enough dwell for the valves to open and close. The PD delay is fixed at 30 seconds, so brief pressure surges do not trigger a needless backwash. A periodic flush resets its clock whenever a PD-started cycle runs, so the timer never doubles up. A third output, marked M on the terminal strip, drives a master valve alongside the two tank solenoids. If the gauge is still closed by the third consecutive backwash, the A terminal switches on through a relay to a bell or lamp. A resettable counter shows how many backwashes have run since it was last cleared. Settings ride through a power cut on a backup battery, and the cycle resumes where it stopped. Alex-Tronix covers the controller with a two-year warranty against original defects.

Key Features

• Two stations plus master valve: Washes two filter tanks in sequence with a master or field valve output.
• Three ways to start: Periodic timer, pressure differential signal or the manual start button.
• PD gauge included: 1-15 psi Murphy gauge with mounting bracket.
• AC or DC power: 115 VAC transformer, 240 VAC option or 12-15 VDC from a battery.
• 24VAC or 12VDC outputs: Switch-selectable for non-latching solenoids.
• Alarm and counter: Alarm after three consecutive PD backwashes and a resettable cycle count.
• Memory backup: Settings and cycle position are held through a power cut.

Technical Specifications