Measuring & Control — Switch Boxes

Two things sit side by side on this page that often get confused. A timer decides when something is switched. A relay box decides what gets switched, and takes the current off the timer. You always need the first; you need the second as soon as more hangs on it than a timer comfortably carries.

Why a timer is not always enough

A timer switches through a contact of its own, and that contact has a limit. Hang more fixtures on it, or equipment that briefly draws far more at switch-on than it does while running, and that contact becomes the weakest point in the whole setup. A relay box solves it by letting the timer operate only a relay, while the box itself carries the load. The LUMii Heavy Duty Timer is the middle road: an analogue 24-hour timer with heavy-duty contacts, intended for a single LED fixture, with 96 switching points a day and no contactor behind it.

Timers and app-controlled sockets

The Fertraso Tijdklok turns your lighting on and off to an adjustable 24-hour schedule, the simplest form and enough for most rooms. The G-tools smart box does it over wifi and has four sockets, two of them permanently live and two switched on time. That saves a separate distribution box when your pump has to run continuously while your lamp follows a schedule. The smart box ships without a plug, so allow for wiring from Installation & Electrics.

Relay boxes that also regulate

The four Cli-mate Mini-controllers are relay box and climate controller in one. The 2 x 600 W switches two fixtures, a 3 A fan and a 16 A heater; the 4 x 600 W handles four fixtures with a 7 A fan. The two Mini-humi versions drive a dehumidifier and a humidifier as well, which is the reason to choose them: not more power, but more kinds of equipment on one schedule. If all you want is to switch on temperature without setting anything else up, the Garden Highpro Tempro is built for that.

Frequently asked questions

Do I need a relay box, or is a timer enough?
Add up what will hang on the timer and look at what that timer's contact is rated to carry. A single LED fixture on a heavy-duty timer is fine; several fixtures, or a lamp with a ballast, belong behind a relay box.

Why does the smart box have two always-live sockets?
Because not everything in a grow room follows a schedule. Your extraction and your pump usually have to run on while your lighting must not deviate from its hours. A box that does both saves separate distribution boxes.

Can I control my fan speed with these?
Switching and regulating are two different things. The Mini-controllers have a fan output that is driven along with the rest; if you only want to set the speed, or have it follow temperature, see Fan Controllers.