how big of an inverter for Direct TV
As I've mentioned on other threads, I'm looking to install an inverter to run my Direct TV components from my batteries. I asked around, called the companies, and determined that; My TV uses abo...
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Rmack1 wrote:
...Winegard tech who said that voltage times amps gives you wattage. Is this correct?
Somewhat correct. Your devices draw total 291W @120V. There is also 10-15% inverter overhead. So the inverter will draw 320W from the battery, waste 30W on heat losses and give you 291W @120V. From the battery you will draw 320W or even more.
Rmack1 wrote:
He also confirmed my suspicion that the dish uses less power after it's finished using it's electrical motors to align itself with the satellites,
Probably. When motors stop, there is less power needed. OTH, when motors start running, for the first few seconds they may draw more than their "usual" 120W, and then you will exceed 291W total.
Rmack1 wrote:
So, I could get away with a 300 watt inverter, if they make them that size.
They make them that size, but read the specs. Sometimes they rate inverter in 300W "continuous power" and sometimes in 300W "peak power", with a small print saying that 300W is allowed for a few minutes only, and for continuous work you should not exceed say, 200W.
Rmack1 wrote:
Question; is there any advantage to inverter overkill? Like, would a 400 watt inverter have any advantages over a 300?
No, as long as you are within its rated continuous power rating. First drawback that comes to mind is that idle current is - usually - higher when inverter rated power is higher. Bigger box, bigger guts, more power needed to feed them.
RoyB is right about dangers of losing control over your power appetite. You watch TV, then the show is boring or there is a commercial and you go to kitchen briefly to run a toaster at the same time, and 300W inverter goes up in smoke. Or put your cordless drill on charger, or something else.
