Inverter install

Cookie

Cookie

Well-known member
Joined
May 5, 2021
Messages
1,628
Reaction score
1,815
OK, I bought a Renogy 3000 watt inverter on Amazon last week.  I want to install in my Motorhome, I am looking to power the TV's and the surround system with DVD player. Hate running generator for something like this.

My question, if I wire it directly to the 110 outlets, when the gennie/moho plugged in will it damage the inverter?  The plugs will have to be wired to both to make work on both, right?  I looked on the internet and I couldn't really find this answer.  I hope this makes sense.

Thanks GD experts

 
No, you don't want to wire both shore power and the inverter to the TV outlet. Just wire the inverter to the TV and stereo outlets. When the gen or shore power is on, it will power all of the other 110v loads and charge the batteries. The batteries will feed the inverter, which is then taking 12v and powering the TV/stereo. 

 
Lord of the Dunes said:
No, you don't want to wire both shore power and the inverter to the TV outlet. Just wire the inverter to the TV and stereo outlets. When the gen or shore power is on, it will power all of the other 110v loads and charge the batteries. The batteries will feed the inverter, which is then taking 12v and powering the TV/stereo. 
Click to expand...
Seems logical and easy, thanks

 
My inverter has a built-in transfer switch to pass the shore power or generator power through when available.  If yours doesn't have that feature, you'd have to do what Steve said. The only downside is that it will slow the charging of your batteries by however many amps the inverter draws.

 
That's why I usually recommend an inverter/charger. They have a built in transfer switch, it's usually much faster than a mechanical transfer switch and they're adding to the other charger to charge the batteries faster while the genny is running.

 
Put a 30amp (or 50) outlet near where you plan to install your inverter - and power this new outlet from your inverter...you should have lugs on the inverter to allow you to hard wire this new outlet.

Plug your motorhome into this new outlet such that when you turn on your inverter your entire motorhome/ trailer is powered by the inverter.  IF you do this, you need to do a few other steps...

1. Make sure your fridge is on propane only, not auto -otherwise your fridge will be powered by the inverter.  Make sure no other high powered devices are being used, unless expected of course (coffee maker), compressor, etc.  Worst case inverter will shut off but wont harm it...i have a renogy 1000w and it just turns off for a few minutes.

2. This one sounds tricky  -and if you google it enough you'll find it...Since you're entire motorhome in plugged into this new outlet (running off the inverter now) - it thinks it's plugged into shore power and a a result your converter starts up / thus trying to charge your batteries...You don't want that to happen of course - meaning, you dont want to charge your batteries while you're using them...double usage.  You can stop this by installing a relay - and activating that relay when your inverter turns on...you should also have a normal 3 prong house style outlet on your new inverter, use it to do this...and tap into where your converter gets it 120v power from - such that when your inverter is on, it turns off power to the converters outlet.   All of this can be done with a more expensive unit that's an all-in-one -but this is the cheapest way to do it and allows all outlets in your motorhome run on a inverter.  Anyway, hope this helps - i did this last year...pretty tweeker, but its easy to do...and only cost ~ 100 bucks for all the parts.

Watch this:




 
At first glance, this would seem like a good idea. If you are the only person who uses the trailer by yourself, it might work. But if you ever bring the wife or GF out in the trailer with you, it might not work.

Here's what happened to me. The first time I installed an inverter in my trailer, I installed it so that the inverter powered 1/2 the loads (one leg) of the loads in the breaker panel, this included one of the A/Cs. One day while I was on a ride, the GF decided she wanted to run the A/C and fired it up. The A/C overloaded the batteries and damaged the inverter, but didn't blow the fuse. She knew she screwed something up, because everything else went off when she turned on the A/C, but she didn't say anything because she didn't want to admit she did it.

When I got back from the ride, I turned the inverter back on and turned on the stereo and the TV, they fried. I didn't know why. I tried the microwave later, it fried. By the time I figured out what had happened and she (finally) admitted to it, it cost me $800 to replace the stereo, TV, microwave and inverter due to the over voltage the inverter provided. The moral to my hard earned lesson is: if you wire up anything in your trailer in such a way that anyone else can screw it up, it will happen and they will deny it.

Another thing I recommend due to this fiasco is an actual battery monitoring system, showing the actual amps put into the battery and amps drawn out, showing battery state of charge in %. My favorite is the Victron Smart Shunt for $130. It's extremely accurate and uses BT to connect to your phone, instead of mounting a display on an inside wall of your trailer.

 
True, but in my case the inverter has overload protection...so worst case they keep trying and it shuts itself off over and over.  Trying to wire half of the outlets was more work than it was worth for me.  Hopefully i dont eat my own words someday 🙂

 
It would really help if you gave us a few more details.  Much like a lot of toy haulers you have an actual plug to use the generator vs shore power, motorhomes are also wired different.  Do you already have a transfer switch?  A little extra planning can make the system work seamlessly.  

 
Another easy way if its just an inverter is to mount it close to batteries and run the thick cables Pos and Neg.

Next / Get 2 thick extension cords and plug them into the inverter (cut the outlet ends off)  / Run those cords inside the coach to a new  110 wall outlet by the tvs,,.....you will mount where is best / Those 2 plugs will only be powered by the inverter

The TVs will only run off inverter / when you are on shore or genny power the batteries are charging...DONE

OR just buy 2 small inverters and plug them in in the 12V plug by the TVs and use those//  That works great too

 
Last edited by a moderator:
Like anything, there is more than 1 way to skin a cat.  In the past, I have also built a small transfer switch using a 120v relay.  When the inverter turns on, it powers up the relay coil and switches the power over to the inverter circuit.  Most toyhaulers only have a couple of outlet circuits, and I powered the circuit or circuits that powered all the tv receptacles I wanted.  Works well, and simple.  a 2 - 4 pole relay will allow powering up multiple circuits easily, and when the inverter is off, they return to being powered by the original power source.  

As mentioned, always mount the inverter as close as possible to the batteries and using a heavy extension cord is not a bad idea to get power to your new gear.

If you want/need help with the relay and wiring it, I can help with that.

 
This is a motorhome, so lots of 110 plugs.  I am thinking the inverter power to the circuit panel, and then run the inverter power to the circuit breakers I want Inverter power (some 110 plugs), they are all separated already.  Water heater, micro, Ac, fridge, washer/dryer will not be touched. and will only run off 110 from gennie or shore.  When I need any 110 plugs to charge phones or TV's, I just need to make sure the Inverter is on.  Seems pretty easy.

Only reason I didn't go inverter/charger is I am being cheap for sure, haha

Next step, where do people add extra batteries for Motorhomes, my two coach batteries are under the steps, no more room there..............

 
wesinls said:
True, but in my case the inverter has overload protection...so worst case they keep trying and it shuts itself off over and over.  Trying to wire half of the outlets was more work than it was worth for me.  Hopefully i dont eat my own words someday 🙂
Click to expand...
If you read my post, the problem wasn't the inverter. The A/C load was about 1600w, the inverter was 3000w. The problem was the battery voltage sagged, like FLA batteries do and the low voltage damaged the inverter, even though it had a low voltage cutoff feature. Just because it has protection circuits doesn't mean they always work. If the inverter had shut off and reset, or just blown up, I would have been better off.

Since then, I've wired up my inverters so they only power the wall plug circuits and tried to make them as idiot proof as possible. Murphy's Law seems to kick in more often in trailers or when you're in the desert. 

 
Cookie said:
Next step, where do people add extra batteries for Motorhomes, my two coach batteries are under the steps, no more room there..............
Click to expand...
Here's my recommendation: switch over to LiFePo4 batteries. A 200Ah LFP battery is just slightly larger than a regular car battery but gives the same amount of power as 3 GC batteries. 2 x 200Ah LFP batteries gives 320Ah of usable power (80% depth of discharge) which is the same as 6 GC batteries. 6 Trojans cost about $900 and will last 4 yrs if watered monthly. They weigh 252 lbs. The LFP batteries weigh 92 lbs, and take up about 1/3 the room. They will last 15 - 30 yrs, depending on how often you use your moho. From a cost vs performance and lifetime perspective, they're the best value in batteries by far. The Ampere Time batteries are down to $665 (prices drop all of the time) but there are plenty of choices, I'd go with whichever one has the best reviews, or best warranty.

 
^^^ good call, will my converter charge fast enough for them?

 
It depends on what amperage it can provide. If it's 50A or so, you could add another 50A or 75A battery charger with Li output setting, up to 14.6V. If it's closer to 100A output, then it's good enough. Chances are it's about 50 or 55A.

Another option could be solar. That's my favorite option, since it's silent and free once it's installed.

 
How did you end up installing it?  Pretty sure I have the same Rv and am curious to see how you went about it as I'm starting to research inverter/charges to install in my rig. 

 
Lord of the Dunes said:
At first glance, this would seem like a good idea. If you are the only person who uses the trailer by yourself, it might work. But if you ever bring the wife or GF out in the trailer with you, it might not work.

Here's what happened to me. The first time I installed an inverter in my trailer, I installed it so that the inverter powered 1/2 the loads (one leg) of the loads in the breaker panel, this included one of the A/Cs. One day while I was on a ride, the GF decided she wanted to run the A/C and fired it up. The A/C overloaded the batteries and damaged the inverter, but didn't blow the fuse. She knew she screwed something up, because everything else went off when she turned on the A/C, but she didn't say anything because she didn't want to admit she did it.

When I got back from the ride, I turned the inverter back on and turned on the stereo and the TV, they fried. I didn't know why. I tried the microwave later, it fried. By the time I figured out what had happened and she (finally) admitted to it, it cost me $800 to replace the stereo, TV, microwave and inverter due to the over voltage the inverter provided. The moral to my hard earned lesson is: if you wire up anything in your trailer in such a way that anyone else can screw it up, it will happen and they will deny it.

Another thing I recommend due to this fiasco is an actual battery monitoring system, showing the actual amps put into the battery and amps drawn out, showing battery state of charge in %. My favorite is the Victron Smart Shunt for $130. It's extremely accurate and uses BT to connect to your phone, instead of mounting a display on an inside wall of your trailer.
Click to expand...
but did you keep the gf?

 
You must log in or register to reply here.
Back
Top