Netafim 4 Output Backflush Controller on DC Power
Four automatic filters on one header need a flush sequence that can run unattended for weeks. Netafim model 31NBCDCL4, item 00105-006260, gives that header 4 outputs for 12VDC latching solenoids. It runs on DC power, from four D-size alkaline batteries, a 12 volt battery, or a rechargeable battery charged by a small solar panel. Each output sits on a plug-in board of two, and the controller counts the boards it finds at configuration. Outputs are handed to the backflush valves first, starting at number 1. An alarm, a delay valve and a main valve, if chosen, take the next outputs in that order. On this four-output unit, adding a main valve leaves three outputs for filters. Any unused last station can be cancelled with the M key. Netafim lists the controller for automatic disc, sand media and screen filters. A mounting bracket is supplied, and the housing measures 9-1/2 x 5-5/8 x 3-1/4 in.
How the DP Sensor Filter Controller Handles Faults
The embedded electronic sensor reads inlet and outlet pressure through two command tubes. Put a 120 mesh filter, installer-supplied, on the high-pressure tube before the red port. When consecutive DP-triggered cycles pass the looping limit, the controller declares an endless loop. It shows the fault, energizes the alarm output and stops treating DP as a trigger. Flushing then continues on the interval countdown alone until the constant DP signal clears. A closed contact on the low-pressure input pauses everything, including the countdown, and a P symbol blinks on screen. If that happens mid-sequence, the flush restarts from the beginning once pressure returns. On a blank screen with a silent keypad, check that every battery is installed correctly. The Main Card needs 6 volts on this DC model. Cycle totals for DP, timed and manual flushes can each be cleared with the plus or minus key.
Key Features
- Four 12VDC latching outputs: Two plug-in boards of two outputs each.
- DC, battery or solar supply: D alkaline cells, a 12V battery or a solar-charged rechargeable.
- Flexible output allocation: Alarm, delay valve and main valve take the outputs after the filters.
- Looping protection: Switches to time-only flushing and raises the alarm after repeated DP cycles.
- Low-pressure input: Pauses the controller and restarts the sequence when pressure returns.
- Mounting bracket: Included with the controller.
Technical Specifications
| Specification | Value |
|---|---|
| Item Number | 00105-006260 |
| Model | 31NBCDCL4 |
| Outputs | 4, 12VDC latching (2-wire) |
| Power Source | 4 x D alkaline (6V), 12V dry battery, or 12V rechargeable with 2 W solar panel |
| DP Input | Embedded electronic analog DP sensor or external dry-contact DP switch |
| Low-Pressure Input | Dry-contact pressure sensor |
| DP Set Point | 1-30 psi (0.1-2.0 bar) |
| Flush Time per Station | 5 s to 6 min |
| Flush Interval | 5-60 min, or 2-120 h, or DP only |
| Dwell / DP Delay | 5-60 s each |
| Looping Limit | 1-10 consecutive DP cycles, or off |
| Optional Outputs | Alarm, delay valve, main / pressure sustaining valve |
| 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 |