Truck mounted 220 volt inverters

[rarebear.nm]

There are 12 volt to 220 volt inverters on the market. I wonder about installing double 440 Amp alternators on a RAM 3500, this is a factory option, and providing 220v power to the trailer. We don't have a generator or solar system, yet and see this as a possible way to provide trailer power for short periods. I'd only use this while in an isolated dry camp environment. I know this one large power plant just for some watts. Questions I have include: 1) will these alternators produce full power at idle speeds, 2) how will a Progressive Industries built-in power protection unit handle the output from such an inverter (true sine-wave vs. modified sine wave) and 3) what is a realistic 220 volt load with 12 volt & 880 amp source? Maybe this is one of those really bad ideas, but what the heck for thinking about it?

[1bigmess]

120v at 880 amps is 10,560 watts. You'll never be able to ever get more than 10,560 watts (theoretically). Period. 120 volts will get you about 88 amps. 220 will get you roughly half the amps.

Vehicle engines are not designed to idle, and alternators don not give full output at idle. Check the cost of wiring for 50 amps at 220 and see if that changes your mind. Is the cost of a good generator so outrageous that you'd rather pay for a 220v inverter?

[twinboat]

Be careful about a 240 volt inverter.

Many just put out 240 volts and not 240 volts, split phase power, that your RV is designed for.

They are for 240 volt items only and have no neutral for 120 volt output.

As far as output of your 880 amp alternators, going from 12 volts to 120 volts is, simplisticly, going to give you 88 amps. That is with a 15,000 watt 240 volt, split phase, inverter.

If you have an actual split phase 240 volt inverter that figured out to 44 amps per side.

Alternators put out there max rating at high speed so you will need to rev up the diesel to 1800 RPMs, to get maybe 3/4s of what the rate them at. Once the get hot, output drops.

You will also need quite the battery to absorb the surges between the alternators and inverter when something kicks on.

If you do all of the research of alternator output, inverter types, engine speed control, batteries and cabling, to do this, you'll probably see that a generator is a better idea.

Disclaimer, this is off the top of my head, actual numbers may be different.

[charliez]

Just curious, what do you need 220 v for?

[rarebear.nm]

You guys answered enough to consider this a bad idea. These some other points I'd thought about as issues. A Honda genset would be cheaper and simpler. Thanks for the weigh-in.

[ResidentEvil]

Another thing to think about:

Not sure what year your truck is, or what engine it has in it, but it may not be a good idea to let the truck sit and idle for long periods of time.

I run a '15 Ram 3500 with the Cummins 6.7l diesel engine, and the manual says in no uncertain terms that you aren't supposed to let the truck idle for longer than 15 minutes at a time.

It may be an easier and cheaper option to set up a small solar array, or go with the genset you mentioned.

[wingnut60]

I think long idling periods is really bad on all the new emissions diesels--the commercial engines are tuned for less HP/TQ and adjusted to account for longer idling.
Nope, you do not want one of the 'Big 3' HP wars engines idling just to output power to an accessory tool/appliance.
The gen is the better way to go.
Joe

[Selah]

Idleing newer Diesel engines for long periods is a big no no. Not advise able.
I think you would be money ahead by simply purchasing a portable Honda generator. No special inverters, truck mods, special wireing,,etc.
This would also allow you to take the truck to the store and still have power at the RV.

[Walt Bennett]

Reading some of this thread leads me to believe a few people think there's 220v being used in their coach. NOT true. A 50 amp service RV uses two separate 30 amp circuits through the power cord to your breaker panel. At the panel, you'll find two 30 amp breakers ganged together, not a 220v single breaker. The power is then somewhat evenly split between the misc. 120v breakers that are actually on two separate circuits. I can state this as fact since I took mine apart when installing solar and leaving one 30 amp circuit straight through (AC and other high current devices) and routing the other through the new inverter and other half of the panel. Since the two supply circuits could be wired to form a 220v single circuit (with a 220v breaker), this causes a lot of confusion with some.

[twinboat]

Originally Posted by Walt Bennett

Reading some of this thread leads me to believe a few people think there's 220v being used in their coach. NOT true. A 50 amp service RV uses two separate 30 amp circuits through the power cord to your breaker panel. At the panel, you'll find two 30 amp breakers ganged together, not a 220v single breaker. The power is then somewhat evenly split between the misc. 120v breakers that are actually on two separate circuits. I can state this as fact since I took mine apart when installing solar and leaving one 30 amp circuit straight through (AC and other high current devices) and routing the other through the new inverter and other half of the panel. Since the two supply circuits could be wired to form a 220v single circuit (with a 220v breaker), this causes a lot of confusion with some.

You should be wired to 2, "50" amp breakers in the MH panel.

It is actually a 50 amp 120/240 volt service. Look at your plug !

They are not seperate, they share a common neutral.

The 50-amp*120/240-volt*3 pole 4 wire grounding Service

This*50-amp*service*has 4 wires with two 120-volt HOT feeds.*It is a*misconception*that this 50-amp RV service is something special.*This service is a STANDARD 120/240 50-amp 3 pole with 4 prongs used for*numerous*applications.*

From this common service we can draw 120 or 240 volts. Each leg is 50 amps @ 120 volts. 50-amp X 120-volt = 6000 watts. But since there are 2 HOT 120-volt* legs at 6000 + 6000 = 12,000 watts to use in the RV or 50-amp X 240-volt = 12,000 watts when used as a 240-volt service.*

Almost ALL 50-amp wired RV's use both sides of the service separately as 120 volt on each leg. Only a few mostly high-end coaches utilize the 240-volt from this*same*service.

The 50-amp 3-pole 4-wire service is superior to the 30-amp service because of the total amperage available.

30-amp 120-volt service = 3,600 watts
50-amp 120/240-volt service = 12,000 watts

[Mark-]

Hello,

Originally Posted by Walt Bennett

A 50 amp service RV uses two separate 30 amp circuits through the power cord to your breaker panel. At the panel, you'll find two 30 amp breakers ganged together...

I can state this as fact...

I can state this as fact; my power cord, after the transfer switch, goes to two 50 amp breakers.

[Walt Bennett]

Originally Posted by twinboat

You should be wired to 2, "50" amp breakers in the MH panel.

It is actually a 50 amp 120/240 volt service. Look at your plug !

They are not seperate, they share a common neutral.

The 50-amp*120/240-volt*3 pole 4 wire grounding Service

This*50-amp*service*has 4 wires with two 120-volt HOT feeds.*It is a*misconception*that this 50-amp RV service is something special.*This service is a STANDARD 120/240 50-amp 3 pole with 4 prongs used for*numerous*applications.*

From this common service we can draw 120 or 240 volts. Each leg is 50 amps @ 120 volts. 50-amp X 120-volt = 6000 watts. But since there are 2 HOT 120-volt* legs at 6000 + 6000 = 12,000 watts to use in the RV or 50-amp X 240-volt = 12,000 watts when used as a 240-volt service.*

Almost ALL 50-amp wired RV's use both sides of the service separately as 120 volt on each leg. Only a few mostly high-end coaches utilize the 240-volt from this*same*service.

The 50-amp 3-pole 4-wire service is superior to the 30-amp service because of the total amperage available.

30-amp 120-volt service = 3,600 watts
50-amp 120/240-volt service = 12,000 watts

Sorry, the PLUG does not determine how many VOLTS one gets - it's how the circuits are wired in the coach. If you've got two separate (but ganged) 50 amp breakers, I'd suggest you had better have a heavier gauge shore cable than is standard, or perhaps someone gave you two larger capacity breakers than is needed. ALL fifth wheels I've seen do not have 220v anywhere. If you claim some 'high-end' ones use 220 volts inside for anything, I've never seen one do so. They all have 120v appliances and lighting. Haven't seen a 220v heat pump, water heater or furnace in any.

[Rockwood27]

Originally Posted by Walt Bennett

Sorry, the PLUG does not determine how many VOLTS one gets - it's how the circuits are wired in the coach. If you've got two separate (but ganged) 50 amp breakers, I'd suggest you had better have a heavier gauge shore cable than is standard, or perhaps someone gave you two larger capacity breakers than is needed. ALL fifth wheels I've seen do not have 220v anywhere. If you claim some 'high-end' ones use 220 volts inside for anything, I've never seen one do so. They all have 120v appliances and lighting. Haven't seen a 220v heat pump, water heater or furnace in any.

A 30A RV will be supplied with a 10 gage, 3 conductor cable, whereas a 50A RV will be supplied with a 6 gage, 4 conductor cable. Both of these cables are of sufficient size for their intended usage.

[Duoglide1]

Originally Posted by Walt Bennett

Sorry, the PLUG does not determine how many VOLTS one gets - it's how the circuits are wired in the coach. If you've got two separate (but ganged) 50 amp breakers, I'd suggest you had better have a heavier gauge shore cable than is standard, or perhaps someone gave you two larger capacity breakers than is needed. ALL fifth wheels I've seen do not have 220v anywhere. If you claim some 'high-end' ones use 220 volts inside for anything, I've never seen one do so. They all have 120v appliances and lighting. Haven't seen a 220v heat pump, water heater or furnace in any.

The coach I am selling has a 220 (240) volt dryer in it with placards stating not to be used on 30amp service.


2007 Monaco Executive 45' 525 ISX