This post is copied from a grow shop website, the company Canatronics is now producing the units under the name GreenPower.
It explains how their contactors work;
Canatronics 6 Way Contactor with Grasslin Timer
Plants are incredibly sensitive to changes in lighting schedules, itâs really important to make sure your lights are reliably on and your timer makes sure theyâre on at the right time. The Canatronics 6 Way Contactor with Grasslin Timer is a renowned high quality, ultra-reliable contactor for up to 6 HPS or MH 600 watt lights or 4 HPS or MH 1000 watt lights. Canatronics Contactors are the original name in reliable contactors and have been used by growers for years. Hand crafted in England, they contain the infallible heavy duty Grasslin Timer and a dedicated auxiliary heater output.
Switches up to 6 lights up with 4000 Watts total load
Easy to use
Dedicated auxiliary heater output
Features an integral Grasslin timer
HO7RNF fire resistant cabling
Wall mountable with attached brackets
Housed in a tough metal box
Canatronics 6 Way Contactor with Grasslin Timer Contains:
1 x Canatronics 6 Way Contactor with Grasslin Timer
How the Canatronics 6 Way Contactor with Grasslin Timer Works:
Most plug-in timers available on the market today will fail if they are used to switch on and off a load such as a grow-light ballast. The Canatronics 6 Way Contactor with Grasslin Timer will safely and reliably switch on grow-lights (and/or fans etc.) by means of highly rugged internal electrical switching components using the schedule that you set on the integral Grasslin timer on the top. The heater is circuited to come on when your light timer is off to offset the lack of heat keeping your plants in the ideal environment.
The Canatronics 6 Way Contactor with Grasslin Timer will switch 1 to 6 lighting ballasts or other electrical equipment with a total power consumption of up to 4000 Watts. Grasslin are very well known for making some of the most reliable timers in the industry. Itâs all housed in a sturdy metal casing.
Using the Canatronics 6 Way Contactor with Grasslin Timer:
The Canatronics unit can be hung from a wall by the attached fixing bracket. With the unit unplugged, programme the timer on the front by moving the tabs on the face of the Grasslin timer to the outer position for those times that you would like power to be on, and set the others to the inner position for the times you would like the power to be off. Each segment corresponds to 15-minutes. A pencil or other small item can be handy for pushing the segments in or out with.
Move the timer-face clockwise until the current time lines up with the arrow. The hands on the clock in the centre will then also correspond to the correct time. There is an override switch to the lower-right side of the clock. This can be set to â0â for âAlways Offâ or it can be set to â1â for âAlways Onâ. The centre position of the switch is for âTimed Onâ and this will be the normal setting for the unit when it is in use to switch your lights on and off according to your set programme.
Plug your ballasts, fans or other electrical items to be switched, into the sockets on the Canatronics Contactor Switching Unit. Make sure that the switches on the outlets are in the âOnâ position. Insert the rubberised mains plugs into separate mains outlets. Ensure the timer override switch is in the middle position. The contactor will now switch your lighting system on according to the programme set on the timer. No more than 6 lights should be switched by the Canatronics 6 Way Contactor with Grasslin Timer nor should more than 4000 Watts be drawn through it as this will cause the unit to be overloaded.
Although Canatronics 6 Way Contactor with Grasslin Timer can handle the switching of up to 4000 Watts, it is worth bearing in mind that traditional (non-digital) HID lighting ballasts draw a considerable surge at switch-on which is well more than their normal running wattage. 6 lighting ballasts being switched on simultaneously may cause the circuit breaker in your consumer unit to trip if that circuit is being run too close to its limit.