On January 14, 2016 at 19:23, fcwilt said...
- Why a contactor as a practical matter?
It's a practical matter because of the cost vs benefits. Contactors are cheap and easy to install. Contactors should be standard practice in all your future new construction (or retro upgrades where it can be installed without tearing into finished surfaces) for exterior lighting loads that are switched, have the chance of being extended or have the potential to take in water.
I've lived in/worked on homes for 40+ years that had dimmers on outside circuits and never had an issue that would suggest a contactor as being required.
In 40 years of working in homes you have never seen a dimming circuit with a contactor because you can't dim a contactor. It's either on or off.
Outside circuits are going to be GFI protected so water getting in is going to trip that.
Where's the GFI protection? If it's holiday receptacles, it's at the receptacle. If it's lighting it's at the panel behind the 8ANS which will fry before the GFI trips.
- Increasing the load outside of spec can happen on any circuit inside or out.
Increasing the load outside of spec can happen, which is why you use a contactor. Just as long as the load is within the spec of the contactor/conductors/breaker it's no worry. Even if the load goes over spec, the 8ANS is protected and the service call is for line voltage and not low voltage. And, even then, the replacement part is a $30 contactor, not a $100 switch.
If you found a fixture or circuit carrying too much load because the wrong bulbs were installed would you not change them simply because somebody else, at some future time, might change them again?
And what you describe is exactly why changing the bulbs is not a permanent solution, whereas a contactor is. I would fix it correctly the first time so I don't have to roll a truck on a service call down the road if someone changes the light bulbs.
Last edited by Fiasco on January 14, 2016 20:23.
