Inverter question

[handirifle]

I know this is a little out of the wheelhouse of "tractor" but I respect the knowledge and experience of you folks. The honesty too. So here goes.

I have a 2000w inverter I plan on installing in our 5th wheel. I ONLY went 2K because the wife wants to be able to use her hair dryer. Anyway, the way she does it is on about 5 min or less then off for 5 min or so and repeat, so it's not continuous use at that level. Here is 1875w, I looked.

After getting it and looking over the manual it also posed another issue I need to solve. They say not to mount it near gasoline or the batteries. ???? They also say to mount it as close to the batteries as you can. OK. I WAS planning on mounting it in the front storage compartment, BUT that is also where my 2K generator is AND the batteries AND 4, 20lb propane tanks. The batteries are both in completely enclosed and vented (top and bottom) to the outside, so I am not AS worried about them. The generator I will eventually move to the rear bumper, but honestly not right away. the propane tanks are there to stay, that is the only place for them.

So I am guessing that compartment is not a good idea. I am considering mounting it in the basement (the storage compartment right behind the above mentioned compartment) since there is a wall between it and the rest of the stuff above, but that will require a little longer and heavier cables. There are 2 aluminum square tubes that run through there that I would probably mount it to, upside down.

I assume you folks are going to tell me to go with the basement mount too? I would just run the cables through that wall and down to the batteries, and the rest of the equipment would be in the forward storage with the tank, generator, etc.

A fellow RV'er with same layout has his mounted up where all the tanks etc are and has had no issues, but I suppose it only take once?

OK that out of the way, I was also wondering about cable size. I have been reading charts till I am cross eyed but it still is not black and white. If I stay with the present 2 batteries, I will be running about 5-6 ft of cable each way, so possible 12ft total. From what I have read 2/0 will handle the amps easily enough, but I am concerned about voltage drop now, if I go with the alternate mounting location. I MIGHT be able to shorten that length if I can move the inverter closer to one end, nearer to a battery. I have to study the rig a bit more.

Do you think 2/0 would suffice? Also when I ordered the inverter, they recommended a fuse holder and 200 amp fuses, which I bought. Is 200 amp enough? I know it will protect the 2/0 wire, but will it handle the full inverter load?

Thoughts?

 

[RNeumann]

2/0 welding wire is fine. Your setup will draw well under 200 amps (about 153 amps at 2000w plus the inherent inefficiency of the inverter so maybe 180 amps) so the fuse size is also correct. Plus the hair dryer is closer to 1400w- not 2000w.

With the distances you are discussing don't worry about voltage drop.

It's hard to recommend installing the inverter against the manufacturer recommendations- with that said the concern is flammable gas from the battery or propane tank coming in contact with a potential spark from the inverter. I'm sure you can come up with a solution that allows you to sleep well in the RV without worry!

 

[3Ts]

I assume you folks are going to tell me to go with the basement mount too?

Yep! you got it. That's what I would do.

For 2/0 wire @ 68 deg F, the resistance is .08 ohms per 1000 feet. So for your application - 12 feet at 200 amps, your voltage drop will be 0.4 volts. Not significant, so you're good on that.

As for mounting location, RNeumann is correct. The concern is flammable gas (hydrogen from the batteries), protect it from that and you'll be ok. The inverter in my RV is mounted under the bathroom sink, next to the water pump. I suppose water leaks are safer than gas leaks.

 

[FredH]

Not sure I would mount it upside down , Still it is Horizontal , so that may be fine . I have had inverters in all 4 of my semi's . Most have been mounted some were between 6' and 8' from batteries . The " Kits " that you can buy to install a inverter are usually worthless as cable is to small for one thing , unless it is a small inverter .
For My application , the biggest issue is not were as in what is it close to , but " Were " I can mount it to be able to mount horizontal , ( Flat ) . Since most , if not all , have circuit boards in them , mounting on the side , against a vertical wall , results in early failure .

Most install instructions I have read , recommend horizontal mounting .

Fred H.

 

[handirifle]

Fred
Thanks, never thought position meant much to electronics. Will have a closer look at the manual. I plan on building my wiring from scratch, and soldering the terminals on. My best location on the basement side of the wall WOULD be a sideways mount on a vertical wall.
3TS
I took a closer look at my options and it looks like it might be closer to 4-6ft total, at least from the extra batteries I will have to install. Seems also most are recommending at least 400AH available for a 2000w inverter.
RNeumann
I was reading elsewhere that the wires in welding cable might be too thin? I don't know why that would make a difference IF you get them all in the terminal. Maybe since I plan on soldering, it might be harder to get them all coated.

My fuse holder arrived today, so for now I have the inverter, fuses and holder. I should get a disconnect switch as well. One friend has both a fuse AND a breaker in the hot line. I am not sure that is needed unless the breaker was weaker than the fuse. I imagine when a 200amp fuse goes there can be some serious sparks, no?

 

[handirifle]

OK I looked over the manual and there is no mention of mounting position. They only discuss clearance, which it will have plenty. So it will be mounted on a vertical wall, in horizontal position. I would like to be able to mount it flat, but there isn't space. Floor space is at a premium in the basement, and non existent in the front storage area. The 2 extra batteries will eat up a lot of what I have.

 

[FredH]

Another tip is if the temp is low , Do Not turn on the inverter and use right away . Basically let it build some heat inside by itself or maybe something that is a very light load . For instance , in my truck , My 17" flat screen t.v. only draws 40 watts but my laptop pushes almost 140 on start up . Both are light loads relative to my inverter size , but are not a heavy load like a 1000 watt microwave .

I can't tell you what size cable I have , Stuff is about 1" in diameter though . Have had them in every truck I have owned , so when installing a new one in a truck , I just go to the local electrical / plumbing store and buy 8' - 10' of red and black . :confused3:

For connections , I use these type :

Stick it in a vise , use torch to heat and fill with solder , then shove the wire down into it and hold for roughly 10 to 15 seconds while solder cools . Never had one come out . Only peel back insulation on wire no more than depth of connector , actually a little less , thus when solder cools , no inside wire is exposed and makes for a neat , tidy connection .

I have only used fuses before and currently . 100 amp in line . Word of advise there , HAVE SPARES !! Nothing like blowing a fuse and not having a spare , ( Not to mention that all the local hardware and auto stores have no idea what you are talking about ) . Know a few owners who have went the circuit breaker route rather than a fuse , only difference is no spares are needed .

Fred H.

 

[handirifle]

Fred
Thanks. Excellent tips.

 

[RNeumann]

Fred
Thanks, never thought position meant much to electronics. Will have a closer look at the manual. I plan on building my wiring from scratch, and soldering the terminals on. My best location on the basement side of the wall WOULD be a sideways mount on a vertical wall.
3TS
I took a closer look at my options and it looks like it might be closer to 4-6ft total, at least from the extra batteries I will have to install. Seems also most are recommending at least 400AH available for a 2000w inverter.
RNeumann
I was reading elsewhere that the wires in welding cable might be too thin? I don't know why that would make a difference IF you get them all in the terminal. Maybe since I plan on soldering, it might be harder to get them all coated.

My fuse holder arrived today, so for now I have the inverter, fuses and holder. I should get a disconnect switch as well. One friend has both a fuse AND a breaker in the hot line. I am not sure that is needed unless the breaker was weaker than the fuse. I imagine when a 200amp fuse goes there can be some serious sparks, no?

The thinner the strands, the more flexible the cable. Plus the insulation on welding cable is of higher quality. Whoever said the wires were too thin for auto or RV use is incorrect. It's up to you what wire to use- this is just what I did.

If you want a means of disconnect (which I did as well) I use one of these-

SB(R) Connector Housings - 5 Amp

As you found out the inverter can be mounted in any direction. The internals (no matter design- transformer, inverter etc) don't need a position or time to warm up.

Typically when you solder you heat both ends together.

I have heard no mention of how you are keeping the batteries charged. It will probably be a bit of a letdown if all you are using is the little 10ga or so wire through the trailer plug. Also, I assume it is, but make sure the house batts are isolated from the vehicle batts to prevent a total loss of power- plus dissimilar batts tend to "equalize" to the weakest one.

 

[handirifle]

When dry camping, for now, the batteries will be charged with a generator, during generator hours. Eventually I would like to do it with solar panels. I will also need to upgrade the converter/charger to a better one, a step down type. That will be before the solar, but will be a little bit in the future. The better charger will be to add longevity to battery life.

This is a 5th wheel, so the only batteries involved are for the 5th wheel. Even if I just stop for short overnight, I usually unplug from the truck.

As for separating them, I will be looking more for a typical battery cutoff switch, if one is heavy duty enough, for a 200 amp circuit.