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HowTo: A low cost lighting sequencer (Pt 1)
( Roger Otis)
Step 5 : The SSR Box
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| | Please note: Building SSR boxes is very serious business. They are for controlling 120 volt circuits. The following is not presented as a solution suitable for your particular lighting control situation. If you use it, it is at your own risk. It is your responsibility to meet your own local electrical safety codes and regulations. It is also your responsibility to size components, to construct units to prevent overheating and know how to safely handle electrical equipment.
I never place the SSR boxes inside or near buildings. I don’t put them in places readily accessible to people. The control boxes are plugged into outlets with GFCI protection. This will probably cause some nuisance tripping in wet weather.
The boxes are constructed of ½” plywood. The length is sized for a cover plate for the power cord entry and fuseholder, 5 receptacles and a cover plate for modular jacks. The cord and plug has a ground and is polarized. The neutral is connected to the neutral side of all receptacles. The ground is connected to each receptacle. The hot strap between individual receptacles is removed. A wire is connected from the hot side of each receptacle to the proper terminal of the triacs.The data lines to the control boxes are flat modular telephone wiring. One is 4 conductor and one is 8 conductor. The 4 conductor cable is usually available at home improvement stores. The 8 conductor cable is available from www.jameco.com. You could use Cat 5 cable if you like. The flat cable is very easy to terminate into RJ45 & RJ11 plugs. The wire used to terminate the modular jacks to the optoisolators needs to be solid wire suitable for punching down on the jacks. I use Cat 5. I use one conductor from each cable as a ground for the common wire connected to the LED in the optoisolator. For the cable combination, this gives two grounds and 10 conductors (one for each ½ receptacle. Do not connect the ground for the electronic circuits to the receptacle ground.
If you prefer, you can fabricate metal or plastic enclosures for the SSR boxes. I usually place the boxes in plastic garbage bags with the openings taped around the incoming cords and data lines.
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