Power Converter to power Inverter

The friendliest place on the web for anyone with an RV or an interest in RVing!
If you have answers, please help by responding to the unanswered posts.
See posts with no answers
S

synctek

Member
Joined
Jan 3, 2018
Posts
10
Hello all.  New to the forum.  There is a ton of info here - Im lovin it!!
One thing I did not find is the answer to the following question:

Can I plug a pop-up camper Power Converter (standard factory) into a Pure Sinewave Power Inverter (1500W/3000W Peak)? 

Background:  I will have a 120AMP/hour 12V battery connected to the Inverter.  The battery is being charged by a Windynation Charge controller connected to a 100W solar Panel on the roof.  My thought was while boondocking, I could run all of the 110v outlets and 12v lights connected to the converter using the power from the Inverter.  When shore power is available, I can remove the plug from the inverter and plug into it.

Thoughts?  Ideas?
 
It's a really wasteful way to do it, but it would work. The inverter is only 80-90% efficient in producing 120v from battery, and then the converter loses another 10-20% when converting back to 12v. Better to just put a pair of jumper cables from the inverter battery to the RV's own house battery. Or is that 120AH battery already the house  battery?  If so, you don't need to do anything - you already have it wired into the lights and such.
 
Thanks for the info Gary.

The battery and inverter will provide power for everything.  Power loss isn't really an issue as it's a small popup trailer and I won't be running any major appliances.  As of now, the camper only has 2 - 110 outlets.  I will have a laptop on occasion, cell phone and a lamp (110) and a 12v pump.  I just want to make sure there aren't any compatibility or electrical issues with running the converter from the inverter.
 
Is the inverter connected to a battery separate from the one in the trailer?  If so, plugging the trailer and it's converter into the inverter will work.

If the inverter is being fed from the trailer battery, or the two batteries are jumpered together, disconnect the converter before plugging the trailer into the converter or you'll set up a loop as the converter tries to charge the same battery the inverter is drawing from.  This is very wasteful as the converter will never catch up with power the inverter is pulling out of the battery and the cascading power will only stop when either the inverter or converter reaches it's maximum output.
 
- Lou

There is a single battery that will run everything and be directly connected to the Inverter.  My thought was to plug the converter directly into the Inverter for boon-docking.  This will power everything in the popup (outlets and 12v items).  When the unlikely option for shore power is available I can simply plug the converter in to the available outlet. 

That said, will there be an electrical or compatibility issue running the converter off of the inverter?
The inverter is 1500w steady, 3000 peak.  I don't want to burn anything up or remove the converter because of the potential of shore power.
 
If I understand correctly, you will be using the battery to power the inverter.
The output from the inverter will power the converter.
The output from the converter will be charging the battery.

Considering the less than 100% efficiency of both the converter, and (especially) the inverter, you can expect to run down the battery rather quickly.

If it actually works, you will have invented the world's first perpetual motion machine.

Joel
 
You have to disconnect the converter before plugging the trailer cord into the inverter, or like Joel said, you'll quickly drain your battery.

-- Unplug the converter if it plugs into an AC outlet

-- Turn off the converter breaker, or isolate the converter to it's own breaker if this also turns off other stuff.

-- Install an on-off switch on the AC input to the converter

Or don't plug the trailer's cord into the inverter.  Since this is a small trailer, either plug your stuff directly into the inverter's outlets or extend the inverter power to where you want to use it.
 
Synctek, what you're asking is a fairly common question, and an understandable one. On the surface, it seems to make sense, but like the others have said, it actually ends up creating an inefficient power loop. Doing what Lou said will work better.

Kev
 
Lou Schneider said:
You have to disconnect the converter before plugging the trailer cord into the inverter, or like Joel said, you'll quickly drain your battery.

-- Unplug the converter if it plugs into an AC outlet

-- Turn off the converter breaker, or isolate the converter to it's own breaker if this also turns off other stuff.

-- Install an on-off switch on the AC input to the converter

Or don't plug the trailer's cord into the inverter.  Since this is a small trailer, either plug your stuff directly into the inverter's outlets or extend the inverter power to where you want to use it.
Click to expand...

That's the approach that I tried, and it works, so long as you remember to to do it. Inevitably, I forgot once. That's how I know that leaving it on will run down the battery rather quickly.

I decided to make sure that it never happened again. I bought a relay with normally closed contacts. I connected the coil to the output of the inverter, and wired the hot leg of the power input for the converter through the relay contacts. Now, when the inverter turns on, it pulls in the relay, and automatically turns off the converter. Something like https://www.amazon.com/Zettler-Miniature-Power-120VAC-AZ2280-1C-120A/dp/B0030G8SC8/ref=sr_1_3?ie=UTF8&qid=1515097937&sr=8-3&keywords=relay+120v will work fine.

As an added touch, I got two 120 V neon pilot lights. The green one is across the converter power, ant the red one is across the relay coil. That isn't really required. but I can see the status of the system at a glance.

Joel
 
If there is only one battery, the simple way is to connect the RV 12v circuits direct to that battery. Also connect the output of a 12v power converter/charger to that same battery. Plug that converter charger in when you have shore power available; other wise it is not plugged to anything. That avoids the power loop problem.

Let the inverter power the two 120v outlets all the time, whether on shore power of not. The converter/charger will replenish the battery as fast as the inverter draws from it, and you already said that the 120v usage is limited.
 
Gary RV_Wizard said:
Let the inverter power the two 120v outlets all the time, whether on shore power of not. The converter/charger will replenish the battery as fast as the inverter draws from it, and you already said that the 120v usage is limited.
Click to expand...

I'm not sure I'm understanding what you're saying, but it is not a good idea to have both shore power and the inverter powering the same outlets at the same time. They almost certainly would not be in phase, and the result would be extremely unpredictable. At best, there would be large, rapid voltage fluctuations, and in all likelyhood, tripped circuit breakers. Damage to to the inverter would not be unlikely.
 
Hi everyone.  Thanks for all the responses!.  The battery will be charged exclusively by solar while I'm boondocking as mentioned in the OP. It (battery) is only going to be physically connected to the Inverter, not the converter. 

Hope that sheds some light on the subject. 

For those of you asking "why?"
I will dry camp more than anything and will almost completely rely on the solar system to charge the battery.  The converter however has 2 110 outlets connected to it which I want to make use out of.  There are a couple places I will go that have shore power though and want to use the converter for that rather than solar/inverter.  In that case I can unplug the converter from the inverter and plug directly into shore power.  Again, the battery is connected to the solar system for charging so I will still have access to the 12v items connected to the battery but the 110v will come from Shore power.
 
Hi Joel.

The camper has only one battery and it will be charged to and charged by the solar system.  The converter does not connect to the battery.  Instead, it will be plugged into one of the Inverter outlets while I dry camp.
I've never plugged a converter into an inverter but thought if there's no battery connected and no issue with overload, it could be made to run off the inverter, providing power to the 110v outlets in the camper and any other 12v items I connect.     

Great Horned Owl said:
If I understand correctly, you will be using the battery to power the inverter.
The output from the inverter will power the converter.
The output from the converter will be charging the battery.

Considering the less than 100% efficiency of both the converter, and (especially) the inverter, you can expect to run down the battery rather quickly.

If it actually works, you will have invented the world's first perpetual motion machine.

Joel
Click to expand...
 
I'm not sure I'm understanding what you're saying, but it is not a good idea to have both shore power and the inverter powering the same outlets at the same time
Click to expand...
You did indeed misunderstand - I did not propose connecting in that fashion. The 120v outlets would be powered exclusively by the inverter.

Synctek seems to have his heart set on doing it his way, though, so the point is moot.
 
thought if there's no battery connected and no issue with overload, it could be made to run off the inverter, providing power to the 110v outlets in the camper and any other 12v items I connect.
Click to expand...

A converter doesn't power 120v outlets - it is  a 12v power source. Are you proposing to use one of the integrated power center boxes, one that has 120v breakers (load center), 12v fuse bus, and a converter/charger all in one package?  For the set-up you appear to want, it would be easier to keep each of those functions separate.
 
Gary,

Dang! I thought for sure it was a converter.  The device that is mounted in the Popup that I referred to as a "Converter" is a [ [6AMP] Series 6400 Model 6406 Electrical Center Power Converter].  There is a three-way rocker switch labeled CONV-OFF-BATTERY.  There is also a 110 10 AMP power outlet on the front and a wired 110v outlet wired to back of the device that sits on the adjacent wall.  Also on the front panel is a 12 VDC fuse.  If this isn't a converter then I am mistaken and clearly have misled the group.  I am a worm and hear-by submit myself for a wet noodle flogging. 

Gary RV_Wizard said:
A converter doesn't power 120v outlets - it is  a 12v power source. Are you proposing to use one of the integrated power center boxes, one that has 120v breakers (load center), 12v fuse bus, and a converter/charger all in one package?  For the set-up you appear to want, it would be easier to keep each of those functions separate.
Click to expand...
 

Attachments

  • popup_power.jpg
    popup_power.jpg
    128.8 KB · Views: 7
The outlets on the front and back merely pass through power provided by the shore power cord.  They don't have any power otherwise.

It's unusual to have a power outlet on the front of a converter, but understandable to simplify the wiring in a small trailer.

A "converter" converts 120 VAC into 12 VDC to charge your batteries.  An "inverter" goes the other way, taking 12 volts in and producing 120 volts ... the inverse of converting.

The "Converter - Off - Battery" switch allows your 12 volt loads to run from either the converter or from the battery.  Older converters like this have a rough, unfiltered output, so you have manual control to switch the 12 volt loads to be powered directly from the converter or battery.  If they draw more than 6 amps from the battery, they'll draw more power out than the converter can supply in charging current, so the battery won't charge.
 
Lou,

Exactly!  So the question is.....can I -safely- plug the converter into the inverter and run it?
Will there be any long term issues?
 
Not unless the Conv-Off-Batt switch turns off the converter in the "Off" position.  Most likely it just changes where the 12 volt lights get their power, in which case the converter will still be connected to the battery and you'll still have the current loop described above.

No long term issues, just short term ones ... draining 6+ amps from the battery in addition to any other load as long as the current loop exists.
 
Lou - To clarify, the battery is not connected to the converter.  It's an old pop-up and has several wiring issues so I'm basically starting over with it.  The battery is connected to the inverter and solar charge controller.  The loop problem mentioned is a non-issue.  The converter has a power cable that is meant to connect to shore power and runs a couple 110 outlets.  The dome light in the ceiling isn't even connected at the moment. 

I think I may leave the Converter alone, remove the 110 outlet from it and wire it to the Inverter.  That setup will still allow me the use of the single 110 plug on the converter when shore power is available. 

I appreciate everyone's input on this.  Thanks ALL!   
 
You must log in or register to reply here.

Latest posts

Members online

Total: 1,020 (members: 24, guests: 996)

Forum statistics

Threads
131,923
Posts
1,387,516
Members
137,674
Latest member
SPK550
Back
Top Bottom