Hunter Solar Sync ET Sensor and Module

Introduction

The Solar Sync is a sensor system that, when connected to a compatible Hunter controller, automatically adjusts watering based upon changes in local climate conditions. The Solar Sync utilizes a solar and temperature sensor to measure on-site weather conditions used to determine evapotranspiration (ET), or the rate at which plants and turf use water. In addition, the Solar Sync sensor includes a Hunter Rain-Clik™ and Freeze-Clik™ sensor that will shut down your irrigation system when it rains and/or during freezing conditions.

A small module connects the sensor to the controller and will automatically increase or decrease watering run times based on changes in weather. The result is a water-efficient irrigation product that promotes water conservation and healthier plants. You simply program your controller like you normally would, and the Solar Sync takes over, eliminating the need to manually adjust your watering schedule.

System Overview and Operation

The Solar Sync System is easily installed on any compatible Hunter irrigation controller. The System consists of the sensor, placed in an area where it can receive full sun and rain, and a module installed next to or inside your Hunter controller. The Solar Sync sensor measures solar radiation and temperature to calculate the daily evapotranspiration (ET) factor for irrigation, representing the amount of water lost by plants due to local climatic conditions. The Solar Sync sensor also includes a Hunter Rain-Clik™ rain sensor that automatically shuts down the irrigation system during rain events, preventing unwanted irrigation.

Program your controller with a mid-summer watering program. The Solar Sync module receives data from the sensor and applies it daily to the controller's water schedule by adjusting the controller's programmed irrigation run times through the seasonal adjustment feature.

Solar Sync Sensor: Measures solar radiation and temperature.

Solar Sync Module: Connects the sensor to the controller and adjusts watering schedules.

System Installation

Installing the Sensor

Mount the Solar Sync sensor on any surface exposed to unobstructed sun and rainfall, avoiding sprinkler spray paths. Orient the sensor upright; the swivel bracket can be adjusted for angled surfaces. Loosen the locknut and screw before swiveling the bracket, then retighten. The sensor is designed to be wired directly to the Solar Sync module. It comes with 40 ft./12 m of wire, extendable to 200 ft./60 m (18 AWG/1 mm diameter minimum).

Note: Place Solar Sync sensor where it can receive full sun. ☀️

Attach the Green and Black wires from the sensor to the corresponding Green and Black wires from the module. For outdoor installations, use waterproof wire connectors.

Rain-Clik™ and Freeze-Clik™ Functionality

The Rain-Clik™ sensor prevents irrigation during rainfall. It uses Quick Response technology to shut off the system within minutes of rain. The vent ring on the sensor can be adjusted to control how quickly the sensor dries out and reactivates the system. Opening the vent speeds up drying; closing it slows it down.

The built-in temperature sensor shuts down the system at approximately 37°F/3°C and below. A "sensor off" indication will appear on the controller. When temperatures rise above 37°F/3°C, automatic irrigation is reactivated.

Sensor Fault Message

If the Solar Sync module displays "Err", check the connections between the module and the sensor.

Maintaining the Sensor

Wipe the clear dome covering the solar radiation sensor every 6 months. Do not use harsh chemicals or abrasives.

Installing and Wiring the Module

Activate the CR2032 backup battery by pulling the insulator. The battery provides date/time backup and has an expected life of ten years. Replacement instructions are in the manual. Use only CR2032 batteries.

Caution: Battery may explode if mistreated. Do not recharge, disassemble, or dispose of in fire. ?

The Solar Sync module can be wall-mounted next to the irrigation controller. A rubber cover protects the module in outdoor installations. Use anchors or self-tapping screws for mounting.

Bypassing the Sensor

If the Rain or Freeze Sensor prevents system operation, "SENSOR OFF" will display. Move the Bypass switch on the controller to "BYPASS" to bypass the Solar Sync's Rain and Freeze Sensor. The Solar Sync will continue to make watering schedule adjustments. Ensure the controller's Rain Sensor switch is in the "ACTIVE" position for the sensors to interrupt watering.

Solar Sync Module Wiring Connections

Pro-C Conventional Controller Connection (PCC Series)

Mount the Solar Sync module inside the controller cabinet using the provided screws. Connect wires as follows:

1. Connect the red wire to the AC1 terminal.
2. Connect the white wire to the AC2 terminal.
3. Connect the blue wire to the REM terminal.
4. Remove the flat metal jumper from the two SEN terminals.
5. Connect the yellow wire to one SEN terminal.
6. Connect the orange wire to the other SEN terminal.

Controller Connections: SEN: ORANGE, SEN: YELLOW, REM: BLUE, AC2: WHITE, AC1: RED

Pro-C Controller (PC Series)

Mount the Solar Sync module on the wall next to the controller cabinet. Use the knockout on the right side for routing wires.

1. Connect the red wire to the AC1 terminal.
2. Connect the white wire to the AC2 terminal.
3. Connect the blue wire to the REM terminal.
4. Remove the flat metal jumper from the two SEN terminals.
5. Connect the yellow wire to one SEN terminal.
6. Connect the orange wire to the other SEN terminal.

ICC Controller

Connect wires as follows:

1. Connect the red wire to the AC1 terminal.
2. Connect the white wire to the AC2 terminal.
3. Connect the blue wire to the REM terminal.
4. Remove the flat metal jumper from the two SEN terminals.
5. Connect the yellow wire to one SEN terminal.
6. Connect the orange wire to the other SEN terminal.

I-Core Controller

Connect wires as follows:

1. Connect the red wire to the AC1 terminal on the controller.
2. Connect the white wire to the AC2 terminal on the controller.
3. Connect the blue wire to the REM terminal on the controller.
4. Remove the jumper wire from the sensor terminal pair (e.g., S1 and S1, S2 and S2).
5. Connect the yellow and orange wires from the module to a sensor terminal pair.

Programming Your Controller

Program your Hunter controller as specified in its Owner's Manual. When setting station run times, enter the time for peak summer watering. The Solar Sync adjusts run times daily based on weather conditions via the seasonal adjustment feature. It is recommended that all programming be conducted with the controller's Seasonal Adjustment set at 100%.

Note: Set station run times for peak summer watering with seasonal adjustment set at 100%. ?

Making Adjustments

After programming, allow the system a few days to gather weather data. If adjustments are needed:

• If the landscape is wetter or drier than desired, use the watering adjustment feature on the Solar Sync module (see page 14) for global adjustments. Refer to the Troubleshooting Guide for more details.
• If an individual zone is wetter or drier than others, adjust the run time for that specific station in the controller.
• When adjusting program run times, reset the seasonal adjust to 100%. Solar Sync will automatically adjust based on measured weather conditions.

Programming the Solar Sync Module

Programming the Solar Sync module involves a few initial steps. Upon initial power-up, the display shows the time of day. Pressing the ➔ button cycles through programming functions, indicated by an arrow at the bottom of the display.

Current Time

Press ➔ until the ⏰ icon is highlighted. The time will flash. Use the + or - buttons to set the current time. The arrow indicates AM/PM. (Note: 24-hour mode requires 50 Hz power input.)

Controller Type

Press ➔ until the ?️ icon is highlighted. Use the + or - buttons to select the correct Hunter controller type.

Region

To ensure accurate measurements, program the Solar Sync module with the typical ET (average July ET) for your region. Use the table below to determine your region. Press ➔ until the ? icon is highlighted. Use the + or - buttons to select your region (1-4).

Region Selection Table

* For Southern hemisphere locations, use the month of January.

Watering Adjustment

If your landscape is too wet or dry, use the watering adjustment feature. Press ➔ until the ? icon is highlighted. Use the + or - buttons to adjust watering from 1 (less water) to 10 (more water). Observe performance over the first few weeks before making adjustments.

Note: For individual zones, adjust run time directly on the controller.

No Water Window

The Solar Sync has a hidden "No Water Window" feature to prevent irrigation during specific periods. Press and hold ➔ for 5 seconds to program it. An arrow will flash at "Start". Use + or - to set the start time. Press ➔ again; an arrow will flash at "End". Use + or - to set the end time.

Calibration / Setup Period

After installation and programming, allow the Solar Sync system to run for a few days at the initial setting. Site conditions may require adjustments to the Region and/or Water Adjustment settings for optimal performance.

1. Install the Solar Sync sensor and program the module (pages 10–12).
2. Allow the system to operate at initial settings for at least 3 days.
3. Observe the controller's Seasonal Adjust. If it appears lower or higher than expected for the time of year, adjust the Solar Sync settings.

• Seasonal Adjust too low: Ensure the controller dial is in "Run". Increase the Water Adjustment scale (max 10). If you reach 10 and still need more adjustment, move to the next lower Region (e.g., 4 to 3) and set Water Adjustment to 5.
• Seasonal Adjust too high: Ensure the controller dial is in "Run". Decrease the Water Adjustment scale (default is 5). If you reach 1 and still need more reduction, move to the next higher Region (e.g., 2 to 3) and set Water Adjustment to 5.

Station Run Times: Solar Sync provides a global seasonal adjustment. Enter peak season watering run times in the controller. If a station's run time seems too long or short despite the correct seasonal adjustment, adjust the station run time directly in the controller program.

Troubleshooting Guide

Specifications / Dimensions / FCC Notice

Controller Compatibility

The Solar Sync is designed for use with Hunter Pro-C (PC or PCC series), I-Core, and ICC controllers.

Specifications

• Power Input: 24 VAC 50/60 Hz (from controller)
• Current draw: 25 mA @ 24 VAC
• Non-volatile memory
• Replaceable 10-year lithium battery: CR2032 (for backup timekeeping only)
• Max distance module from controller: 6 ft./2 m
• Max distance sensor to module: 200 ft./60 m
• Wiring: 18 AWG/1 mm or 20 AWG/0.8 mm diameter minimum from the sensor to the module
• UL Listed
• Direct burial and UV approved

Dimensions

• Solar Sync Sensor: 3"H x 9"W x 1"D (7.6 cm x 22.9 cm x 2.5 cm)
• Solar Sync Module: 1-3/4"H x 5"W x 5/8"D (4.4 cm x 12.7 cm x 0.6 cm)

FCC Notice

This equipment has been tested and found to comply with the limits for a Class B digital device, pursuant to part 15 of the FCC Rules. These limits provide reasonable protection against harmful interference in a residential installation. This equipment generates, uses, and can radiate radio frequency energy. If not installed and used per instructions, it may cause harmful interference to radio communications. There is no guarantee that interference will not occur in a particular installation. If this equipment causes harmful interference to radio or television reception (determined by turning the equipment off and on), the user is encouraged to try to correct the interference by one or more of the following measures:

• Reorient or relocate the receiving antenna.
• Increase the separation between the equipment and receiver.
• Connect the equipment into an outlet on a circuit different from that to which the receiver is connected.

Certificate of Conformity to European Directives

Hunter Industries declares that the irrigation sensor Solar Sync complies with the standards of the European Directives of "electromagnetic compatibility” 87/336/EEC and “low voltage” 73/23/EEC.

Peter Wagemann
Project Engineer

CE