Netafim Automatic Filter Backflush Controller With Valve Control
A four-filter disc or media station flushes well only if inlet pressure holds up while one filter is cleaning. This Netafim model 31NBCAC4, item 00105-006210, handles that with 4 outputs and an option to control a downstream pressure sustaining valve. When a main valve is configured, it opens first and a pre-dwell gives pressure time to build. Valve 1 then flushes for the set time, followed by a dwell before valve 2, and so on through the station. An optional delay valve can be set alongside, with its own output just before the main valve. Power is 110 or 220 VAC, and a built-in supply delivers 24VAC to the solenoids. The embedded electronic DP sensor triggers a cycle when the pressure drop reaches the set point. Where no embedded sensor is used, an external dry-contact DP switch wires to its own terminal. Automatic disc, sand media and screen filters are all supported. The kit includes a mounting bracket for the 1.3 lb housing.
Wiring and Checking a 4 Station Flush Controller
Each pair of outputs sits on a plug-in card with terminals for Out A, Out B and a common. Always disconnect power before inserting or removing one of those cards. Wire the 24VAC solenoids to the outputs in the same sequence as the filters on the manifold. Bring the high-pressure command tube to the red port through a small 120 mesh filter, and the outlet tube to the black port. Set the DP delay so the reading must hold for 5 to 60 seconds before the controller acts. If the display stays dark, look first at the power LED on the supply. With the LED off, the 2 amp fuse may have blown or the mains feed may be missing. With the LED on, the Main Card should read 24 volts AC. The controller handles operating temperatures from 32 to 140°F. The case measures 9-1/2 x 5-5/8 x 3-1/4 in.
Key Features
- Four 24VAC outputs: On two plug-in cards, expandable in pairs to 10.
- Pressure sustaining valve control: Main valve with pre-dwell from 5 s to 6 min.
- Optional delay valve and alarm: Assigned to the outputs after the last filter.
- Mains powered: 110 or 220 VAC with a built-in 24VAC supply.
- Embedded or external DP: Electronic DP sensor or a dry-contact DP switch.
- Mounting bracket: Supplied with the controller.
Technical Specifications
| Specification | Value |
|---|---|
| Item Number | 00105-006210 |
| Model | 31NBCAC4 |
| Outputs | 4, 24VAC solenoids |
| Power Source | 110 VAC 60 Hz or 220 VAC 50 Hz, built-in 24VAC supply |
| Power Supply Fuse | 2 A |
| DP Input | Embedded electronic analog DP sensor or external dry-contact DP switch |
| DP Set Point | 1-30 psi (0.1-2.0 bar) |
| Flush Time per Station | 5 s to 6 min |
| Pre-Dwell (Main Valve) | 5 s to 6 min |
| Dwell Between Stations | 5-60 s |
| DP Delay | 5-60 s |
| Optional Outputs | Main / pressure sustaining valve, delay valve, alarm |
| Operating Temperature | 32-140°F (0-60°C) |
| Dimensions | 9-1/2 in H x 5-5/8 in L x 3-1/4 in D |
| Weight | 1.3 lb |
| Included | Mounting bracket |