how big of an inverter for Direct TV

[Rmack1]

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 about 33 watts

The 'Genie' receiver about 18 watts

The Winegard Trav'ler dish uses 120

And the SWM system that I need to run my Genie also uses 120

This last part was determined by a Winegard tech who said that voltage times amps gives you wattage. Is this correct?

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, but he didn't know what the difference was.

So, I could get away with a 300 watt inverter, if they make them that size.

Question; is there any advantage to inverter overkill? Like, would a 400 watt inverter have any advantages over a 300? Would it run cooler, more efficient, anything like that?

Thanks

[Almot]

mena661 wrote:
My sat dish is 12V (King Dome). Only draws 2.68 amps in seek mode. Are there some that are 120V?

The OP only said "...uses 120". Maybe it's time to tell us - 120 of what? :)... And if it's not 120V, then what 120V devices do they have in total, i.e. what this inverter will have to run, including electronics?

[mena661]

pianotuna wrote:
Hi mena,

No, but folks end up finding other items they wish to power.

True but a 300W will power a LOT of stuff. You'd be amazed. My new rig unfortunately has a lot of power hogging stuff and I have yet to overload the inverter. I'd really like to switch out the electronics with low power stuff but I can't justify that. I might switch out the DVD player/receiver unit with just a plain receiver as the unit is on its way out.

[pianotuna]

Hi mena,

No, but folks end up finding other items they wish to power.

[mena661]

pianotuna wrote:
Hi,

I'd still go for the Morningstar inverter--it can do 600 watts for ten minutes so it would certainly get your dish up and in place.

My sat dish is 12V (King Dome). Only draws 2.68 amps in seek mode. Are there some that are 120V?

[Almot]

600W surge is nice. GoPower 300 has 450W surge which may be enough though. Depends on how much surge those motors put out at start-up. I myself have GoPower 175 MSW, don't need more watts, cost me $20. Less TV time, more fishing time for me.

[time2roll]

Typical RV plug is good for 8 amps or about 100 watts max.
May get low voltage shut down before you even get full wattage.
You need a 150w or less inverter to use the 12v connector.
May not be enough power especially all at once.

This is why I suggested the hard wire behind the circuit panel.

[Shadow_Catcher]

Morningstar SureSine 300W 600W surge for 10 min low idle power (no fan)

[dougrainer]

I will give you my experience and knowledge. The OEM's have found that ANY type inverter LESS than 600 watts will not work correctly in your set up. I have found that some LCD TV's need a hi watt surge to start them up. Once they are started, they consume that 33 watts or so. Going less than 600 watts will probably just cause problems. Spend the money for the 600 or higher. Doug

[pianotuna]

Hi,

I'd still go for the Morningstar inverter--it can do 600 watts for ten minutes so it would certainly get your dish up and in place.

[Almot]

Cig lighter plugs usually have low limit of wattage that you can draw. I wouldn't try running 300W through it.

[Rmack1]

smkettner wrote:
I recommend 300w sine wave. 300w is plenty and the wiring is simplified due to the lower power vs 600w+. Should be able to use existing battery feed to the panel and a small transfer switch to put 120v power in the existing tv branch circuit. No wire to pull, just make connections.

GoPower has low idle current draw and a provision for a remote power switch.

Sweet.

Question; does it have any way to use a 12v plug, as in the 'cigarette lighter' type plug to power it? That sure would make my installation far easier.

[Rmack1]

donn0128 wrote:

Rmack1 wrote:

donn0128 wrote:
Remember you can turn off the dishes power once it has homed. So that is a savings. You are going to want a pure sine wave inverter to begin with. Get one around 800 watts and install it correctly and go happy.

I don't think that is true.

The only way I have of cutting off the power to my Trav'ler, short of unplugging it, is to hit the on/off button on the little controller box, and this would begin the shutdown/fold-up sequence.

I suppose I could try unplugging it, but that seems pretty inelegant. I would be surprised if it still functioned, but what do I know?

That's exactly how you do it. My traveler has been up for 5 months now and as soon as it locked onto the signal I unplugged and replugged it. No power draw. When I want to move or put it down all I do is turn it on, let it home and then do the normal power off. The antenna does not need any power feeding it after it has found the correct birds. The SWM power supply provides the 19V to the LNB. Just remember all of this stuff is drawing power all the time. So batteries are not going to last very long. That is the main reason I use a non SWM system when boon docking.

OK.

Thanks for schooling me on that.

[Almot]

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.

[Learjet]

I use a samlex 300 PSW converter to easly run my 26 tv (non-led), directv reciever H25 and swm power inserter. The power inserter doesn't use that much. All of my stuff adds up to @ 150 watts.

I bought from here for $133 link.........................

[mena661]

smkettner wrote:
I recommend 300w sine wave. 300w is plenty and the wiring is simplified due to the lower power vs 600w+. Should be able to use existing battery feed to the panel and a small transfer switch to put 120v power in the existing tv branch circuit. No wire to pull, just make connections.

GoPower has low idle current draw and a provision for a remote power switch.

X2