Dimming and scheduling controls are a increasingly becoming a necessity for any business employing high intensity LED grow lights. The grow light controls options may appear to be endless, however not all horticultural lighting control solutions are developed equally. This guide covers different types of grow light controls and important considerations when selecting a control solution or grow light dimmer for your LED grow lights.
Timers & contactor panels
There are a few ways to control grow lights; this article is going to focus on controls that use a 0-10V dimming signal, however we should touch on the simplest control method - controlling the lights through the mains AC power. Smaller growers and businesses may use a plug in timer or a grow light timer. This method may be more cost effective and simple for a very small number of lights, however as the number of lights increases, the complexity in switching larger circuits grows, making a contactor panel necessary.
Contactor panels are often installed in large facilities, and were commonly used with HPS lights. Contactor panels are typically custom built by a UL certified panel shop, and require electricians to install, so planning for the longer lead times is an important consideration. Due to the custom nature of contactor panels and installation labor, costs can be as high as $140-200 per light in a larger greenhouse. Your facility must be designed to accommodate the contactor panels and all of the conduit runs that come from the panels in accordance with electrical code and local regulations. Finally, contactor panels are not able to dim lights - they only switch lights via the AC power connection. With new dim-to-off LED grow lights that can be dimmed or turned off with a low voltage control signal, contactor panels are becoming a less popular choice.
Manual grow light dimmers are simple devices that plug into the dimming interface on a grow light and offer entirely manual control. The advantage to a manual dimmer is simplicity and cost. Manual dimming solutions lack scheduling capability, and manual adjustments to lights may be too labor intensive for larger operations. Manual dimmers can be a good fit for situations where the light intensity does not need to be adjusted often, such as seedling propagation, clone propagation, and tissue culture.
Wired lighting controllers offer simple plug and play installation, and are able to control many lights per controller. Some wired lighting controllers can be scheduled to turn on and off at specified times, but may not allow for more sophisticated dimming schedules, like sunrise and sunset dimming or multi step dimming for energy management purposes.
Many manufacturers offer a simple wired controller with their lights; be sure to ask the manufacturer whether the controller they are pairing with lights has been tested with the advertised number of lights, what cable lengths have been tested, and whether dim-to-off has been tested for the specified number of lights.
Some wired lighting controllers, such as the Hydro-X from Trolmaster, can be connected to a wired Ethernet Internet connection, and offer some app control functionality. Trolmaster lighting controls are capable of scheduling lights, but are not able to implement multi-step dimming schedules. Controlling multiple Trolmaster controllers from one app is possible, however each device must be edited individually since the app lacks zone management capabilities.
Consider these factors when selecting a wired lighting controller for your lighting system:
- Does the wired controller support dim-to-off? On how many lights does the controller support dim-to-off?
- Can you easily understand the control status of your controller from the user interface? How much training will you have to provide to staff?
- How many steps are involved in changing settings? If you have a large facility, how much work is involved in changing settings on many controllers?
- What happens to the lights if the controller fails or looses power? For light sensitive crops like cannabis, your lights should stay off if the controller fails or looses power.
- If the controller has scheduling capability, how does the controller stay on schedule if power is lost? How does the controller keep time?
- What support options are available?
GrowFlux offers lighting controls that connect to the wired 0-10V interface on grow lights, then communicate with the GrowFlux App and other controllers through a wireless GrowFlux Mesh network. Our controls are designed with many of the reliability considerations covered in this article, and work with any commercial cultivation control system.
Fully wireless controls
Wireless controls for grow lights are a relatively new option, with several lighting manufacturers offering wireless controls installed on each individual light. Most often, these controls use a Bluetooth Mesh protocol, however some manufacturers offer wireless grow lights with 2.4GHz protocols like Zigbee, Thread, WiFi, and others.
Some important considerations to understand when selecting any wirelessly controlled grow light include:
- Are the controls easy to use? How much training will you have to provide to your staff?
- How many grow facilities have the wireless lighting controls been installed on? What is the track record for success? Many wireless solutions have only been tested in the general lighting market and have little track record in horticulture.
- What happens if a light looses its wireless connection? Does the light have a stored schedule to fall back on?
- If your wireless grow light controls have scheduling capabilities, where is the time stored?
- What protections are in place to prevent lights from accidentally turning on during the dark period in the event of power interruption or loss of connection?
- What is the wireless range? Does the wireless signal perform in your particular use case? Be aware that many wireless protocols may struggle with metal grow room walls, metal racking systems, thick plant canopies, and installations with hundreds or thousands of wireless lights.
- What fallback options are present for manually controlling your wireless lights if your gateway, wireless connection, or climate computer fails?
- Can you easily re-configure your wireless grow light without physical access, specialized tools, specialized software, or on-site technicians?
- Can your wireless grow light controls be updated remotely?
- Is your equipment supplier able to offer technical support for your lighting system? Some equipment manufacturers license wireless technologies and are far removed from the experts that can really help, creating a support headache.
Bluetooth Mesh controls can scale to larger networks of lights, but these controls come with several limitations that may affect usability:
- Bluetooth mesh devices can interact directly with a smartphone, but unless an always-on gateway device is present, the connected smartphone with control app must be physically present to make changes to the lighting control network
- Re-zoning a device often requires physical access to the lights, which are sometimes mounted out of reach
- Most Bluetooth Mesh based lighting controllers for grow lights don't offer any visual feedback that settings are properly stored, or that the device is successfully connected
- Bluetooth Mesh based lighting controls use the 2.4GHz spectrum, which is crowded and has potential to cause reliability issues
- The wireless range for Bluetooth Mesh based controls is limited, sometimes to distances as short as 50 feet
- Bluetooth Mesh lighting controls were originally developed for indoor lighting applications, and lack failsafe features specific to the horticulture market, like robust timekeeping and failover functionality in the event of loss of communication
GrowFlux offers a single light controller that addresses these limitations; it is available through select partner grow light manufacturers and on most lights offered by Horticulture Lighting Group. GrowFlux offers solutions to equipment manufacturers seeking wireless controls for individual lights, including fully waterproof modules, wireless PCB modules, and firmware options. Learn more