Converter Questions

[brclark82]

The current 5th Wheel I?m looking at has 50 amp service but a 65 amp converter.

I understand that 50 amp service is actually a 100 amp 120V service since it?s 50 amps at 240v split in 2.

Does this mean that can only safely use 65 amps or 7800 watts instead of the full 12000 watts possible from a 50 amp service or am I missing something and these things don?t correlate?

I ask this because other models I?ve looked at don?t advertise the converter amps and this one seems to be advertising it as a positive feature leaving me to wonder if it?s soemthing I need to be aware when making a decision.

 

[John From Detroit]

You are looking at apples and potatoes (not even oranges)

The 50 amp. is "Up to 50 amps per leg. 120/240 volt A/C)
The 65 amps is 12 volt DC. two almost isolated systems (The common point is the converter)

But the only effect the converter has on over all A/C is this.
IF the batteries are HUNGRY and I mean 50% or lower SOC for GC-2 type. (75 for most others). then the converter will likely be putting out right close to the full 65 amps. an likelu drawing arimd 7 amp from ONE of the 50 amp legs.  Or about the same as an ELectric Skillet.

Once the batteries have had some "lunch" (about 2-3 horus) the current drawn by the convertert drops to around 1-2 amp. A/C  Output may go that low as well.

But the converter rating is DC OUT to charge batteried and run DC stuff.

 

[brclark82]

Well I barely understand what your saying but I get the jist. I?ll look into dc and what batteries are used for while on shore power a little more and see if I can wrap my head around it a little better.  But good to know they are completely unrelated.

Thaanks

 

[Larry N.]

To expand on John's comments a bit: the 50 amps of AC are at 120 VAC, while the 65 amps are 12 VDC (battery). DC amps (at 12V) represent around 1/10th the power that AC amps do at 120 V, since power = volts times amps. So that 65 amps at 12V DC would be in the neighborhood of 6.5 amps converted to AC at 120V. I use rough figures because conversion inefficiencies and other things make that not exactly 10:1. Just trying to keep this part simple.

In reality, as John says, on 1 50 amp RV service, there are actually two legs of 50 amps at 120V AC, making 100 amps total, where a 30 amp RV is only one leg of 30 amps at 120V AC. The whole thing can be confusing to those not used to working electric.

 

[John From Detroit]

I see a lot of confusion in a few areas (not just electrical).

I will state one problem I have is that I have been working with electrical, electricity and electronics. for over 50 years. I have a certification in ELectronics so this stuff is darn near instinctive for me.

So I have problems understanding how people can NOT understand.

But then I recall that when it comes to Diesel Engines I know the basics. but I'd never want to try and fix one less it's a "St Joseph of Cupertino" issue.  I have had one of those (he is the patron saint of test takers.. WHY.. Well he had one test where the odds of him knowing the answer was like 1 in many THe question was chocen at random by taking a Bible putint it Spine down and letting it open to whatever page it opened to. then pointing at random... To the only passage in the entire BIble he was 100% sure of).

Though the poor mechanic was stumped. I identified a Fuel Filter (Simple observation of the fuel path) and knew about Algae in Diesel fuel.. 1 New filter. One bottle of Algae be gone and it was good as new. 25 years old, genuine "Antique RV" but good as new.. Blue Bird Bus.. Fantastic ride. Looks new too.

 

[Lee Ann1]

I want to go the other direction. I have a fema trailer with no batteries, no AC and no heat. My converter is bad and is a 55amp. Can I replace it with a 35amp to power lights only? 35amps are cheaper .

 

[QZ]

I want to go the other direction. I have a fema trailer with no batteries, no AC and no heat. My converter is bad and is a 55amp. Can I replace it with a 35amp to power lights only? 35amps are cheaper .

You might look at something like a Meanwell power supply. They sell lesser brands called megawatt but if buying that brand don't push it hard. I have both and the megawatt didn't like being run hard

 

[John From Detroit]

I want to go the other direction. I have a fema trailer with no batteries, no AC and no heat. My converter is bad and is a 55amp. Can I replace it with a 35amp to power lights only? 35amps are cheaper .

Likeley yes. especially if you upgrade to LED lighting. IN fact a 35 amp with LED lights might be as good as a 55 without.

THe major power sucker on the 12 volt side of life is the furnace and I don't know what kind they put in FEMA trailers so... You may not even ned 35 amps.

 

[Lee Ann1]

Thanks, This fema trailer has been gutted and there is no heater. The hot water seems to be all electric as is the full size fridge. I'm not even going to mess with the AC have already bought a portable unit I'm using while fixing it up. Will order the 35am right now. Thanks

 

[QZ]

Thanks, This fema trailer has been gutted and there is no heater. The hot water seems to be all electric as is the full size fridge. I'm not even going to mess with the AC have already bought a portable unit I'm using while fixing it up. Will order the 35am right now. Thanks

Are you sure it will do what you want without a battery?

 

[John From Detroit]

Do you even HAVE a 12 volt system? Or all the lights 120 v.

SO long as all you are running is lights you don't need a battery.. You can put in a couple of heavy duty 120 volt outlets as I did (15/20 amp outlets 12 ga wire one to a circuit breaker) and use electric heat.

 

[Lee Ann1]

Yes, I have a 12v system and a bad converter. I hooked a battery up yesterday to make sure the lights would work before I spent money on new converter. Lights did come on. The only other thing that came on was a switch under kitchen cabinet with a red light. I think that might be the switch to original hot water heater. The hot water heater it has now plugs into the 120v outlet and has a new switch. It seems to be working with no battery or propane.  Thanks

 

[John From Detroit]

Ok if lights work off battery the best Converter for use without battery is the Progressive Dynamics 9100 series.. IF all you need is power for lights and perhaps a fan or 2 I'd got with the smallest one thy make..

TAPE OFF battery leads and IDENTIFY them (use red and black tape).

Now.. why the 9100.. Less expensive than teh 9200 and if say 5 years from now you decide you really need a battery (You can convert the 9200 into a 3 stage charger plus for about 25-35 dollars. Takes a screwdriver, that's all. and a plug in Charge Wizard.

Depending on the mounting of the converter can take as little as 5 minutes and 4 of 'em are opening the package.