Intermatic SS8 and transformer

[eonibm]

Bear with me, I am a newbie DIY. I would like to use an internally (ie inside the house) mounted Intermatic SS8 Self-Adjusting Digital In-Wall Timer to control a 300w transformer. The SS8 is rated at 15 amps (for incandescent which I assume outdoor halogen lights are) so does that mean I can't put more than 180watts of lighting (12 volts x 15 amps) on the transformer? Or is it not more than 1800 watts (120 volts x 15 amps). I noticed in another post that people seem to be controlling 300w Transformers with these switches.

Also, I thought I would just have the SS8 mounted in a gang box that controlled an outlet that would have the transformer plugged into it. But I've noticed that some people mount the SS8 right inside the transformer box. Why do they do this? Is it easier or cheaper (or both) than mounting it separately in the transformer box?

Thanks!

DIY in Toronto

[sitelights]

The formula for amps is watts divided by volts; the 15 amp rating of the SS8 is equal to 1800 watts. Remember that the SS8 is switching the primary (120v) side of the transformer not the secondary (low voltage) load.

As far as I know, I am the only one who has integrated the SS8 into a transformer case. I did it just to see how it would look and perform. As it happened I had an application for this SS8 controlled MDL 2 X 300w transformer shortly after I made the adaptation. I have another unit just like the first on the shelf in my shop. Details can be found using the search engine: SS8

I would caution anyone using the SS8 to control an outdoor receptacle to mark the receptacle as "lighting only" since using the receptacle for an electric motor driven device or an electric heating tool such as a paint stripper, etc could overload the SS8. Of course since the receptacle would be switched on only at night the chances of damaging the SS8 would be highly unlikely but possible.

As a further caution, note that the SS8 is compatible with a dimming device but that device should be rated for use with a magnetic low voltage transformer. Use of an electrical motor driven device or fluorescent lighting could be deadly to the dimmer as well.

The controlled receptacle could be used for holiday lighting AND a transformer as long as the total load is under 15 amps.