Additional inverter

Topic: Additional inverter (Read 1041 times) previous topic - next topic

Additional inverter

August 01, 2017, 12:16:21 pm

I'm fixing to add an additional 1000w inverter for the Tv system and to keep phones charged. I'm going to
Install it with a manual transfer as discribed on Beamalarm. Question is could one draw power from either the house side of the boost section or the isolater, rather than the 12 panel feed? The feed for that panel looks like is fused at 90A?

Re: Additional inverter

Reply #1 – August 01, 2017, 02:31:11 pm

What kind of TV system uses 1000 Watts of power? My first thought is that 1000W is overkill by a big margin.

If you need to draw heavy current, I would locate the inverter next to the OEM inverter/charger in the bay next to the house batteries. Nice short cable run. If you can get away with a much smaller inverter, the isolator or boost terminal would work. Just keep in mind the long cable run to the house batteries and likely voltage drop if drawing very many Amps. You can always give it a try and measure actual voltage drop under load.

Re: Additional inverter

Reply #2 – August 01, 2017, 02:39:55 pm

Easy way is to mount inverter under center dash fed from 12 volt panel in front of pass. seat and run one 120 volt line up side of windshield to overhead compartment. I run 40 inch tv, vizio 5.1 sound system, traveller sat system and several usb ports for phone off one 300 watt psw inverter. That way I can shut off the power hungry big inverter when dry camping and only use when I need microwave, coffee pot etc.

Re: Additional inverter

Reply #3 – August 01, 2017, 03:30:58 pm

Maybe someone can help me understand the inverters power consumption?

At zero use it says 2ADC if on?

The manual says 88% effeciency. So does that mean if drawing a 1000 watts ac it's using 12% more DC than the actual load in AC?

Hence the cooling fans?

Are the smaller inverters more efficient? And have that much smaller losses?

How much battery extra discharge are we talking about for a normal days use?

Or let's say a 500 watt AC refer with a 5 hour per day compressor on. How much actual battery discharge savings are we talking about on a 1000 watt inverter versus on my sw 2812?

Re: Additional inverter

Reply #4 – August 01, 2017, 03:39:28 pm

Yes 1000watt is over kill for just the TV. However e will be adding a res frige we en the current one dies. Yes my big inverter is an old freedom and draws 5 amps just on stand by. Bob what does your 2812 draw just on stand by add that to whatever load is on it. An inexpensive small inverter is way cheaper than a new main inverter.

Re: Additional inverter

Reply #5 – August 01, 2017, 04:20:37 pm

2 amps DC

My inverter guy mentions that over long use the heart 25 internal contractors surfaces corrode and reduce the charging current being generated to the batteries.

Figured out at a measured bulk charge of 70 amps versus the original 130 I was running 50% more noisy gen hours to get to the absorb charge plateau. More or less float.

At .44 gph gen fuel consumption it was coating me $1.25 an hour plus increased future maintenance charges to run the extra gen time.

When we got the coach the disconnected hour meter was at 986. Reconnected it. Now at 1102. Five years.

Obviously not a overly expensive thing at $150 worth of fuel but the noise from our exposed gen if we dry camped was not relaxing.

The most my 50% SOC MK 8G8d's have accepted in bulk charge is around 110 amps out of its rated 125.

But the system self learns as I understand it as far as what the batteries will accept especially with the battery temp sensor on the sw2812.

Noticable at high temps the freedom 25 without a temp sensor on our serial number unit was overcharging the batteries versus what I currently see without a almost constant charge voltage adjustment based on temps at the battery.

Low charge rate from worn contractors. Non learning controls. Less current draw at idle. Less 12 volt power use on inverting on the appliances because of the full sine wave increased power output. No damage to sensitive electronics. Easier to adjust control panel. Battery temp sensor. Twenty year old inverter

All the above helped my decision to spend the CB's.

All the consumed battery 12 volt will need to be replaced. I think that it more efficient to transfer the 110 volt power through the wiring then small 12 volt wiring then converting it remotely to 110?

Re: Additional inverter

Reply #6 – August 01, 2017, 06:21:08 pm

Bruce,

As long as the place you take the positive for your fuse and then wire and then 1000 watt new inverter is SIZED FOR THAT AMP LOAD, it really does not matter where you connect it. Yes, you will need to consider any other loads you will be running through that/those circuits at the same time.

Assume you are going with a Pure Sine Wave inverter.

Re: Additional inverter

Reply #7 – August 01, 2017, 07:10:18 pm

Yes pure sine wave.

Re: Additional inverter

Reply #8 – August 01, 2017, 07:44:31 pm

I would run it with #8 stranded direct to the house batts. with auto re-settable breaker.I did that, put my 300 watt pure sine wave in the over head by the TV. Runs 32" TV, Satellite 2 receiver's and an in-motion sat.along with modulator for rear TV. I even leave the DVD plugged into it, because I am lazy!
I have a small 100 watt for the rear TV. I did this, because every hiccup and transfer of power, made the satellite reload. Works flawless. We even record going down the road in-motion (not HD)
If I ever do the new refer, I will put a third small inverter for it. So I can turn of the video one off at night and just have the refer going.
Chris

Re: Additional inverter

Reply #9 – August 01, 2017, 08:09:05 pm

Hmmm, I think I would use larger cable. 1000 watts at 12.5 volts is 80 amps, and should allow for surge up to 2X amps - 160 amps when fridge compressor starts. I would go at least 2 gauge per the wire chart for single unbundled cable. If the run is over say 10 feet I would go 1/0 gauge. Keep in mind that the run length is the wire length x2, in other words 10 feet is 20 feet of wire for positive and negative cables. In addition to grounding the inverter case where its mounted, I would also run the negative cable back to the batteries (don't rely on frame ground for inverter current).

American wire gauge - Wikipedia

Re: Additional inverter

Reply #10 – August 01, 2017, 09:18:37 pm

If you want to run the fwd tv, etc plugs and the fridge, why not take power from the isolator and mount inverter in compartment at end of bed [one with transfer switches in it] and just remove those two circuits from the regular inverter panel at end of bed and plug into your new inverter. Your heavy 12 volt wiring would be very short and you would use the 110 wiring you already have.

Re: Additional inverter

Reply #11 – August 01, 2017, 09:27:37 pm

Jim C, that's what I be doing. Going to use a manual transfer sw. That way don't have to be concerned when the big inverter is needed for short periods. I don't know if any of the less expensive transfer switches are fast enough for the tv or Wally Dish receiver.

Re: Additional inverter

Reply #12 – August 01, 2017, 11:20:06 pm

Quote from: prfleming – August 01, 2017, 08:09:05 pm

Hmmm, I think I would use larger cable. 1000 watts at 12.5 volts is 80 amps, and should allow for surge up to 2X amps - 160 amps when fridge compressor starts. I would go at least 2 gauge per the wire chart for single unbundled cable. If the run is over say 10 feet I would go 1/0 gauge. Keep in mind that the run length is the wire length x2, in other words 10 feet is 20 feet of wire for positive and negative cables. In addition to grounding the inverter case where its mounted, I would also run the negative cable back to the batteries (don't rely on frame ground for inverter current).

American wire gauge - Wikipedia

I meant #8 for a 300 watt. I agree with that with a 1000 watt.The 300 watt called for #10. I personally don't see anything heavy enough at the dash to tie into. Any wire I would go to the batts direct. Super easy.

Re: Additional inverter

Reply #13 – August 01, 2017, 11:21:30 pm

Quote from: bbeane – August 01, 2017, 09:27:37 pm

Jim C, that's what I be doing. Going to use a manual transfer sw. That way don't have to be concerned when the big inverter is needed for short periods. I don't know if any of the less expensive transfer switches are fast enough for the tv or Wally Dish receiver.

I doubt they would be fast enough for a sat receiver.

Re: Additional inverter

Reply #14 – August 01, 2017, 11:22:38 pm

Quote from: jcus – August 01, 2017, 09:18:37 pm

If you want to run the fwd tv, etc plugs and the fridge, why not take power from the isolator and mount inverter in compartment at end of bed [one with transfer switches in it] and just remove those two circuits from the regular inverter panel at end of bed and plug into your new inverter. Your heavy 12 volt wiring would be very short and you would use the 110 wiring you already have.

I did that in my last coach. Worked awesome.

Re: Additional inverter

Reply #15 – August 01, 2017, 11:46:19 pm

With a small inverter connected directly to your batteries, no need to worry about transfer times or switches. Leave it on all the time. Your big inverter/charger will keep batteries charged all the time when on shorepower or generator. When not, shut off your invert section on the big inverter, then only load on batteries is small inverter and it's load. If you have a good battery monitor system, you can see SOC and adjust gen or sp time accordingly, if you do not have solar.. Fridge is a bigger load, but I leave my tv and sat on small inverter 24/7. I have 640 watts solar, so batteries normally 100% by !0 am on a sunny day. KISS for me.

Re: Additional inverter

Reply #16 – August 02, 2017, 12:38:17 am

That is exactly my plan, just connect the TV and entertainment electronics directly to a small inverter. Consider them 12 volt appliances, with a master switch to the inverter. No need for a transfer switch.

Re: Additional inverter

Reply #17 – August 02, 2017, 07:42:30 am

No one has shown the actual power consumption differences between the large old, large new and a smaller new inverter in use as far as I have seen here or able to find.

The heavier power consumption from a larger inverter idea has been mentioned many times. Not sure if that's actually true.

Does a larger inverter at small loads actually use more power than a small inverter at a larger percentage of its design loads?

A less expensive work around I understand.

Seems to be a background idea here that a closer to the actual load needed smaller full sine wave inverter will consume less power than a larger unit at the same load.

Any info would help me understand.

Had not run into the small inverter consuming less power than a larger inverter at the same load before.

Re: Additional inverter

Reply #18 – August 02, 2017, 08:28:43 am

The efficiency rating would determine the power consumption of the inverters under load. I believe all the conversation is about idle consumption. The smaller ones draw less at idle.

Re: Additional inverter

Reply #19 – August 02, 2017, 10:06:35 am

Quote from: jcus – August 01, 2017, 11:46:19 pm

With a small inverter connected directly to your batteries, no need to worry about transfer times or switches. Leave it on all the time. Your big inverter/charger will keep batteries charged all the time when on shorepower or generator. When not, shut off your invert section on the big inverter, then only load on batteries is small inverter and it's load. If you have a good battery monitor system, you can see SOC and adjust gen or sp time accordingly, if you do not have solar.. Fridge is a bigger load, but I leave my tv and sat on small inverter 24/7. I have 640 watts solar, so batteries normally 100% by !0 am on a sunny day. KISS for me.

I have exactly the same setup. Approximately 600 watts solar. I leave the 300 watt on 24/7. when dry camping. That way the DTV TIVO doesn't have to reload, plus we have shows recording all the time. I rarely see much drop in batts at all. In the morning, we run the gen set for 45 min. to make coffee. My wife loves her curling iron and blow drier.

Re: Additional inverter

Reply #20 – August 02, 2017, 10:13:47 am

Quote from: Caflashbob – August 02, 2017, 07:42:30 am

No one has shown the actual power consumption differences between the large old, large new and a smaller new inverter in use as far as I have seen here or able to find.

The heavier power consumption from a larger inverter idea has been mentioned many times. Not sure if that's actually true.

Does a larger inverter at small loads actually use more power than a small inverter at a larger percentage of its design loads?

A less expensive work around I understand.

Seems to be a background idea here that a closer to the actual load needed smaller full sine wave inverter will consume less power than a larger unit at the same load.

Any info would help me understand.

Had not run into the small inverter consuming less power than a larger inverter at the same load before.

It's more the glitch Bob, with every transfer. Gen start mainly, but alos from unhooking from shore power.
I can't give you spec numbers, but I guarantee that little 300 watt draws way less then that big old heart inverter.
If I leave the heart on all night, the batts are way down in the am. If I leave the 300 watt on, I hardly see a difference in batt. condition.

Re: Additional inverter

Reply #21 – August 02, 2017, 10:20:27 am

Bruce, I put a 1000w ps inverter in about 4 yrs ago under the end of bed and changed out the 120 wiring as Dick mentions in article. I have the res fridge (smaller one) and this inverter also powers the tv etc and a couple of plugs. I have put a switch in just before the tv etc so if not using them they can be turned off to save a bit of overnight power. I also put in a DPDT switch on side wall of bed to allow power from shore/gen and main inverter OR new inverter. I connected power 12v to the 12v panel main feed and with a fuse. Have not had a single problem with all this and we boondock a lot using solar as you know.
Just follow his set up and all will be well. Keeping it under bed end makes for easy wire changing.
JohnH

Re: Additional inverter

Reply #22 – August 02, 2017, 10:54:27 am

I tried an experiment several years ago. I had a new high dollar outback 2800 watt inverter/charger and a trimetric 2030 battery monitor with 6 wet cell 8d"s. With no load at all on inverter and inverter on, and solar disconnected, Trimetric showed a steady use of 47 watts by inverter in no load state. Not a big deal if you have a big battery bank and solar, but for guys with only 2 8d's [say 225 amp hours usable at 50%] That is 120 amp hours, or half your capacity without running anything!!
This was my system and yours may use more or less, but every big inverter/charger I have used draws at least 35 watts at idle. I have a go power 300 psw and it with my 40 inch led tv on standby only use 18 watts on the trimetric.

Re: Additional inverter

Reply #23 – August 02, 2017, 12:25:44 pm

The anecdotal info is helpful. Thanks. Will remember to ask my guru when we get home about this,

My control panel here in the coach shows little or no difference in the float charge rate with the inverter on or off plugged in to shore power.

My first thought is that the coach has a lot of plugged in devices that probably consume some power and the smaller inverter with a dedicated load lessens the plugged in but not on loads.

If every breaker were open the inverter would be at true idle as it's direct to battery. The sw 2812 does have an adjustable trigger load before it turns on I see.

Not sure how much difference it might make, if any.

We all learn together.

I still wonder if there is an actual draw difference running a 500 watt load on a pure sine wave 1000 watt inverter at 88% effeciency or a 2,800 watt inverter with the same efficiency rating at the same load?

The heart freedom 25's efficiency specs in the manual say it has at best a 94% effeciency rating with its full load being 88%.

My understanding is that all inverters have internal contractors to switch power.

My guru showed me different sized ones. The sw 2812 are smaller than the old heart freedom 25's.

But they all wear from use.

$800 to rebuild the old freedom was not worth it to me.

Lots of wire tightening and board cleaning he says. Plus the contractors are buried deep inside it seems.

I tested our inverter and alternator when installed by running the icemaker and refer compressor and a large crock pot during a five hour drive,

Plugged in dash voltmeters did show large voltage changes at times and the old monitors picture would jump at times but the rebuilt leech/ Neville and the sw 2812 and the three 8g8d's did fine.

The 7832 dometic in our coach has the compressor in the freezer side plugged into the inverter in the outside compartment and the Dometic chest refer was on underneath the coach. I assume it runs 12 volt with the engine on but not sure.

Versus run the gen to run the refer compressor and the crock pot I thought I would test everything.

Worked fine

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