grasfulls
Senior Member
- Location
- San Bernardino. CA
A client with a rather long driveway had the landscaper install several embedded in asphalt driveway LED lights, cumulative wattage is around 150 watts. The client wants the lights to come on at night whenever there is motion at either end of the driveway. We made use of some spare #10's at the gate to power a motion sensor/photocell rated at 250watts incandescent, then mounted another at the top of the driveway. Evidently the landscaper used a 600 watt transformer, I need to confirm that it is not 300 watts, but I want to assume 600 for my questions. The transformer is within 8 ft of the top sensor. The sensors are in parallel and their outputs were directly to a plug for the transformer. The top sensor failed within 2 days.
We installed a 30amp rated relay to feed the power to the transformer so we can feed the sensors without a common tap from the sensor to its internal contact, we have ordered higher wattage sensors. We are still using a single source of power, we can segregate and put the sensors on a different circuit from the transformer.
My questions:
1) Is it ok to install transformers much greater than the load they will be driving?
2) What are reasons to stay within, say 25-30% of the load, if any reason at all
3) Is there an current inrush or a "Bounce-back voltage or current" that could damage the feeding components?
a) is our relay going to be safe?
I have attached a base schematic.
Thanks!
gare
We installed a 30amp rated relay to feed the power to the transformer so we can feed the sensors without a common tap from the sensor to its internal contact, we have ordered higher wattage sensors. We are still using a single source of power, we can segregate and put the sensors on a different circuit from the transformer.
My questions:
1) Is it ok to install transformers much greater than the load they will be driving?
2) What are reasons to stay within, say 25-30% of the load, if any reason at all
3) Is there an current inrush or a "Bounce-back voltage or current" that could damage the feeding components?
a) is our relay going to be safe?
I have attached a base schematic.
Thanks!
gare