User Manual for DEMA 0960.NANOC Conductivity Controller

Quick guide from the manual

The 0960.NANOC is a microprocessor-based controller designed for irrigation water systems to automate conductivity control and chemical dosing. This manual provides instructions for installation, operation, and maintenance. Always disconnect power before opening the front panel or performing wiring.

Installation and Wiring

The controller operates on 100-240 VAC. It should be connected to an isolated circuit breaker with a true earth ground. Avoid mounting in locations with direct sunlight, extreme temperatures (below 0°F or above 120°F), or high vibration.

• Wiring: Prewired units include a 16 AWG power cord and 18 AWG relay output cords. Conduit units are provided with liquid-tight fittings.
• Safety: Never run low voltage signal wires (probes, flow switches, water meters) in the same conduit as high voltage (115VAC) wires.
• Relay Configuration: The relay card supports both powered relay output and dry contact relay output, configurable via jumpers.

Front Panel and Operation

The controller features a keypad for navigation and three modes of operation:

• Run: Normal operation mode. Displays system values. Returns to this mode automatically after 3 minutes of inactivity.
• Menu: Used to adjust settings. Press MENU to access, use arrows to navigate, and ENTER to select.
• Force: Allows manual activation of relays. Press FORCE to toggle relays on/off or return to auto.

Conductivity Sampling Methods

The controller offers three methods for sampling conductivity:

• Continuous: Constantly reads the sensor and activates the relay based on set points and differentials. Recommended for most irrigation systems.
• Timed Sampling: Samples at periodic intervals. The pump relay turns off at the end of the sample duration if the reading is below the set point.
• Sample and Hold: Samples at intervals, then holds the blowdown valve closed for a set period to allow for stabilization before checking conductivity again.

Calibration

The controller updates conductivity readings every two seconds. To calibrate:

1. Ensure the conductivity scale is set so the setpoint is near the middle of the range.
2. For continuous sampling, calibrate with the probe in a steady stream of water.
3. For Timed or Sample and Hold methods, use the calibration menu to force the pump relay on to ensure a fresh sample before calibrating.
4. If the conductivity scale is changed, you must reset the calibration in the Diagnostics menu.

Maintenance

The primary maintenance task is cleaning the conductivity electrode. If the unit fails to calibrate, the electrode is likely dirty.

• Cleaning Procedure: Record the current reading, turn off water flow, remove the electrode, and clean the metal tips with a clean cloth and mild cleaning solution. For scale deposits, use a mild acid solution.
• Verification: After cleaning and reinstalling, record the new reading. If a change is observed, the electrode was dirty. If no change occurs, cleaning may be needed less frequently.

Troubleshooting

If the unit displays false readings, clean the electrode or calibrate the unit. If there is no system power, check the power source, fuse, and ribbon cable connections. If outputs are not energized, check for no flow conditions or clogged pipes.