T.V. won't work off Inverter

[Tom]

Oops, I misread the part of the question about splicing and agree with Rolf that it's best not to splice. Just another connection to potentially fail. If you're unable to crimp the connectors, a battery or welding store will do it for you.

 

[John From Detroit]

They sell two types of fuse blocks for high amprage fuses (you need a very large fuse for an inverter that size, I'm guessing about six hundred amps) one type has standard bolt type studs you hook wires to (THIS IS WHAT YOU WANT) and a 3rd wire to hook up to it.  The other has wire clamps.  I have that kind.. IT works well too.  (The set screw in that clamp takes a chevy Brake Wrench believe it or not,  ONE BIG SCREW)

The switch I would suggest hooks to the battery post and the cable hooks to it, It is a knief switch,  Of all the disconnect switches I've seen this one has the following examples.

1: Simple, nothing simpler

2: Reliable, and should it need cleaning, easy to clean

3: Low cost, nothing less expensive

Everythign else I've seen is more expensive, harder to service and more prone to failure..  This is one case where you get more the less you pay.  Common disconnect switches are rated as high as 700 amps when this kind,  More expensive (and slightly better looking) are often rated no more than 200 amps and can not be fixed when they fail.

 

[Just Lou]

They sell two types of fuse blocks for high amprage fuses (you need a very large fuse for an inverter that size, I'm guessing about six hundred amps)

John, as usual, after reading one of your posts, I come away more confused than before. (i.e. you suggest a 600 amp fuse for a 1750 watt inverter ?)

Are you saying that I need to fuse my 2500watt inverter at more than 600 amps?  say 800 amps?

Why do I think that if I ever draw over 250 amps for any period of time that I've got a serious problem.  I would rather the fuse blow than the tires melt off the coach.  What am I missing here?

BTW - It would generally be cheaper (I didn't say desireable) for the disconnect switch to fail than for the fuse to blow.
Forget I said that, I was being silly.

lou

 

[Tom]

Lou,

Please don't fuse that inverter at 600 amps  ;D  200 amps will be about right for yours and 150 amps for the 1750 W inverter mentioned, although folks might check their owners manual. The one in the photos in the library article is a 3,000 W (continuous) inverter and IIRC I have it fused at 250 amps. The fuse hasn't blown in almost 6 years of heavy use.

I've never had one of the marine (sealed) style switches fail in over 20 years of use.

 

[judway]

With the 1750 Watt inverter. The input current exceeds the current carying capacity of the Harbor Freight switch. To get the spec, go to http://www.harborfreight.com/ and type in 92688 for the model number. I wouldn't hesitate using it with a 1 kW unit but the 1750 is too much. So the knife switch looks good. I would get a 200 Amp fuse which has rectangular electrode end pieces and drill a hole in each electrode to bolt to the cable. Wrap the unit with tape or put it in a piece of 3/4" PVC pipe to protect it and not get shorts. A fuse holder costs a lot of money.

I now use the Xantrex RS400 sinewave inverter to power all of my electronics. I run a 24" RCA CRT TV, the satellite receiver, a DVD recorder and a 20" LCD TV receiver all at the same time. I believe the RS400 is now below $300. Seems that CW had them a while back. I believe the XS400 includes the remote switch. The remote switch also had a pilot LED indicating "ON". The RS400 doesn't have lines in the picture like the quasi-sinewave ( we called 'em quasi-squarewave back when I used to design 'em) 1200 Watt unit. I have tried both.

Wayne

 

[judway]

Sorry. The XS400 from CW is now $409. They must have been on sale when I found the lower price. I paid $69 for the Xantrex 1200 at Sam's.

Wayne

 

[John From Detroit]

Sorry, yes, for a 2,000 watt inverter they suggest a 300 amp fuse (1.5 time the max draw) for the catastrophe fuse

So for a 1750, around a 200 250 should do it

Xantrex notes the inverter has one heck of an inrush surge when it first kicks over to inverter mode. A "Stand alone" inverter would not (more than likely) do this.

Don't know where I got the other figure from. 

But you do need to go about 50 percent over what you expect to draw which in your case is 170 amps (roundly) so 250 would be my selection of fuse.

 

[Tom]

The input current exceeds the current carying capacity of the Harbor Freight switch.

Wayne, that's why I recommend the Guest, Perko, or Blue Sea marine switches. They're rated between 350A and 450A continuous.

 

[Shadowman]

The saga continues.

Since the local CW didn't have the items I needed to complete the project, and were completely useless, I don't think customer service is their strong suit, but I digress.  I ended up having to order the fuse, remote switch, extra length of cable, from the website that I ordered the inverter from.

So tonight I thought I would be smart and hook up the inverter to make sure it works before I start drilling holes. Probably the only smart thing I've done this season.  Well, got it all hooked up with the big cables. Plugged the TV in, which kicked right on, as I am glowing in my final success, the alarm sounds on the inverter and shuts down. When I initally turned it on it had over 12 amp showing on the read out, but within a matter of seconds it was down below 10.5 which is when the inverter shuts down. As I'm boxing the thing up to send it back I thought, what would cause it to drain the battery that quick? So I decided with my great wisdom, I might want to check the water level on the batteries. As I pulled the plug off, I noticed that the water level was a bit low. A bit low? Each of the batteries took almost 33 oz of water. So I filled them and put them on a trickle charge. I'll start the process over again in the morning with fresh batteries and hope that they actually hold a charge and I haven't fried them.

Anyway, if you are reading this and are not shaking your head in disgust, I hope you can learn from my mistakes, I'll post tomorrows results.

 

[John From Detroit]

Make sure the batteries are fully charged,  My pair of Group 31's powers a 2,000 watt inverter usually w/o problem

 

[rsalhus]

Trickle charging your batteries ain't gonna help!  You need to put a battery charger on those puppies and pray that they'll come back to life.  And it's not going to happen overnight.  According to an article I posted here last July, Battery Basics you'll have to charge those two batteries (I'm assuming you have two 110 AmpHour batteries with a 0% State of Charge and a 10 Amp battery charger) a minimum of 31 hours to get them back to a full charge.

And back to a previous question I asked you.  Have you thought about how you are going to ventilate the inverter compartment?  You don't want hydrogen gas (given off by your batteries) leaking into that compartment.  You have to think about that before installation.  You said there is an airtight compartment above the battery compartment but it sounds like both of these are within a common compartment.  To ventilate the inverter compartment, you might have to do that in a wall that is not common to the battery compartment (like the back wall).  John in Detroit mentioned how he ventilated his inverter compartment.  Maybe you should think about doing something similar or else move the inverter to an adjacent compartment.

 

[Shadowman]

Rolf,

Thanks for the tips on charging, I'm hoping the batteries come back to life, I'll search for your topic to make sure I've got everything covered.

As for the ventilation in the compartment, I've thought of a couple of ideas, where I can isolate the ventilation. The basement compartment that I'm mounting the inverter in goes clear through to the other side of the MH. It is a pass through part of the basement, so I can ventilate it on the opposite side. Since the area is pretty large I don't think there will be a problem. I also plan on building a "fence" around the inverter so that as items may shift in the comparment during travel, the will not fall into or on top of the inverter. The other option is to mount it on the basement door closest to the inverter I can mount a vent on the top section of the top which is isolated from the battery compartment as well.

Please let me know if you think this is sufficient or do I need to rethink the ventilation design.

 

[rsalhus]

Shadowman,

You won't need to search for the article on Battery Basics, just click on the underlined link here or in my previous post.

I'm having trouble visualizing your basement battery compartment.  I understand it's a pass through compartment, but are the batteries completely isolated from the rest of the compartment?  If not, then I don't think you ought to put the inverter in that compartment.  OTOH, if the batteries are completely isolated and ventilated, then you can probably get by without any extra ventilation for the inverter mounted in the pass through compartment provided that you leave plenty of open space in the compartment for air to circulate.  That means not packing the compartment very full or taking things out that will remain out (like tables, chairs, BBQ, etc.) when the inverter is used.  Personally, I wouldn't like to put a vent in any of my compartments unless I was completely sure that it would filter out everything except air.  Cracking open the compartment door is always an alternative for ventilation.

As for where to mount the inverter, I would first want to mount it as close to the batteries as possible, within reason.  I would then want it to be near the roof of the compartment, if possible, so that things packed underneath it don't slide into it.  You should have easy access to it for removal, and still have room all around it (including the back of it if that's where the fan is).  I wouldn't even think about mounting it on the compartment door.  Does it come with a mounting bracket?  There are lots of things to consider here, and you need to really take your time in the planning stage.

 

[Gary RV_Wizard]

Shadowman,
Get back to basics with your battery(s). How many, how big and what condition?  An inverter has to draw 10x as many DC amps to produce the AC amps need for your tv or whatever. If the tv draws 300 watts @ 120VAC (2.5 AC amps), that means the inverter will pull 25 amps @ 12VDC from the batteries for the AC output plus a bit more because it is not 100% efficient. 25 amps is not a small continuous draw on a battery and many batteries cannot handle it for very long. Even a brand new and fully charged group 24 12V deep cycle will only sustain that about 2-3 hours before the voltage drops below the inverter's threshold (usually 10.5V). Older batteries or those needing water (like yours) may last little time at all.

 

[Shadowman]

Update on progress.

RV Roamer, to answer your question I have 2 deep cell 750 AMP marine batterries in parallel. After I filled them with water and left them on a trickle charge overnight (2amp), I had fully charged batteries. So before putting them back in the MH, I connected them together and attahced the inverter. Before I put any load on the inverter it was reading 12.7 Amps. When I turned the TV on, and it did turn right on, I went out and monitored the amp reading on the inverter for about 5 minutes. The inverter was reading 12.1 - 12.2 back and forth, for the entire time. So I think I have solved that part of the problem.

Now that I'm confident it works, I spent the remainder of the afternoon, drilling, and running wires from point A to Point D. I'm still waiting for the fuse, disconnect switch, and remote switch from the dealer, so I haven't closed everything up and sealed it off.  I've gotta tell you, it was a little nerve racking drilling holes in the MH like that, but I have everything run. I even ran the inside wiring in the MH, which I might add, turned out rather nicely.

I should have the rest of my materals today and if so, I will be hooking it all together. Thanks again to everyone who has offered advise, provided guidance and enjoyed the adventure with me. I'll check back and let you know how it all turns out once everything is up and running.

 

[Shayne]

Wrong batteries but I'll let the guys that know the facts tell you why you need Golf cart batteries.

 

[John From Detroit]

When you read the size of the batteries instead of reading the Cold Cranking Amps (CCA) which is what you 750 AH batteries are, read the 20 hour AH rate.. I'm guessing it's a bit lower, like perhaps 80... That is how much power you have

Golf Cart batteries come in 3 sizes 220,230 and 240 AH, and that is a bunch of power

However a pair of group 31 12 volt batteries in true deep cycle types will also give you ove 200 AH, 260 per the labels on mine, and one actually delivers it's share of 130 AH, the other is better.

 

[rsalhus]

After I filled them with water and left them on a trickle charge overnight (2amp), I had fully charged batteries.

No you didn't!  You'd have to live near the North Pole in the winter time to be able to fully charge two dead 80AH deep cell batteries (reading less than 10.5 V) OVERNIGHT with a 2-amp trickle charger.  You probably read the voltage right after you charged them, right?  Is that when you got the 12.7V reading?  You should let the batteries rest at least three hours before reading them after charging to get a proper reading.  Also, did you know that you do serious damage to a battery whenever the voltage drops below 10.5V?

One more thing.  You shouldn't have to remove your batteries from your RV to charge them.  If you have room to get the battery charger clamps on them where they sit in your basement compartment, and you have access to 110V, you can charge them where they are.

Before I put any load on the inverter it was reading 12.7 Amps.

I went out and monitored the amp reading on the inverter for about 5 minutes. The inverter was reading 12.1 - 12.2 back and forth, for the entire time.

I think you mean Volts here and not Amps, right?  A reading of 12.1V means the SOC (State of Charge) of your batteries was less than 60%.  So that means your batteries probably weren't fully charged to go from 100% SOC to 60% SOC in five minutes.

 

[Gary RV_Wizard]

RV Roamer, to answer your question I have 2 deep cell 750 AMP marine batterries in parallel. After I filled them with water and left them on a trickle charge overnight (2amp), I had fully charged batteries. So before putting them back in the MH, I connected them together and attahced the inverter. Before I put any load on the inverter it was reading 12.7 Amps. When I turned the TV on, and it did turn right on, I went out and monitored the amp reading on the inverter for about 5 minutes. The inverter was reading 12.1 - 12.2 back and forth, for the entire time. So I think I have solved that part of the problem.

rsalhus has it right - those batteries were no where near fully charged. A fully charged 12v battery will usually read around 13.3-13.6v immediately after removing the charger. And that's volts you are reading, not amps.

And that 750 amp CCA rating is irrelevant - you want to check the Reserve Capacity (minutes) or the amp-hour amp rating  to get an idea of how long the batteries will actually provide power for inverter power usage.  Yours sound like typical Group 24 or maybe Group 27 "marine" batteries, which are usually only fair to middling at deep cycle applications. I would guess 80-100 amp-hours of total power each and a practical use of 50-60 AH each.  Here's a good place to learn battery basics:  Battery Stuff

But at least you got the system running and hopefully the batteries will take a full charge. Plug the RV in and let the charging system charge them for a a couple days and they should come up to full power. Then experiment to see how long you can actually run the tv plus a few lights and the usual 12v loads, e.g. the fridge powered on.

 

[Shadowman]

No you didn't!  You'd have to live near the North Pole in the winter time to be able to fully charge two dead 80AH deep cell batteries (reading less than 10.5 V) OVERNIGHT with a 2-amp trickle charger.  You probably read the voltage right after you charged them, right?  Is that when you got the 12.7V reading?  You should let the batteries rest at least three hours before reading them after charging to get a proper reading.  Also, did you know that you do serious damage to a battery whenever the voltage drops below 10.5V?

One more thing.  You shouldn't have to remove your batteries from your RV to charge them.  If you have room to get the battery charger clamps on them where they sit in your basement compartment, and you have access to 110V, you can charge them where they are.

Sorry for being so liberal with my wording, based on the technical nature of the advice I've been given, I should have guessed Type A Engineering personalities. Which, I'm not knocking in the least bit. I'm not an electrical expert, but plan to be after this adventure. At any rate, I would have been more specific in the charging times and verbiage etc... had I known better.

Your all correct, I was talking about volts and not amps, my bad. When I said overnight, I should have been more specific in that it was 23 hours and 15 minutes of charging at 2 amps after an initial 10 amp charge for 1 hour.  I realize I don't have to take the batteries out, however my big head would not fit in the remaining space of the battery compartment, so it was difficult for me to check the level of the water and fill if necessary, I don't have all the fun gadgetry. As for full charge, I should have been more spefic and indicated a 92.465% charge.

I hope no one takes offense. I really do appreciate all the advice and schooling I get here and all the great folks there are. However, I have worked with engineers a lot and I love to give them a bad time. In the future I will not be so liberal in my explanations. Again, please don't take offense I love the advise and I appreciate the time everyone takes to help others.