Be gentle....first MOD questions!

Seniramsu · November 25, 2016

Hello,

Since the truck is home and now it's time to get it ready for the inspection with the Highway Patrol. I called and talked to the inspector and for my "separate 120V system," I was told I needed an inverter or generator. My 120V shore power connection would not do and my current inverter that is tied into the truck batteries will not be sufficient.

I've just about fried my brain reading up on inverter/chargers.............generator/inverters. All the different ways to connect and use them. I think I have decided on a 3000W generator/inverter. I would like to build a platform behind the fairings on the driver side and wire it into the truck.

My question is..........will it be an issue to run one of these portable generators going down the road? We take some pretty long trips and would like to keep the little ones occupied with some tv/movies.......spoiled I know.

This is how I am thinking of wiring things up. Truck is a 2013 Volvo 780 with the factory installed 15amp distribution center for shore power. I would like a setup that can grow if needed. I realize I could get by cheaper with a few batteries and an inverter.

I would like any suggestions on my setup as I know there are some really smart folks on here.

r/,

Brad

Darryl&Rita · November 25, 2016

The people that you need to talk to would be the inspector. What are their requirements?

"separate 120V system," I was told I needed an inverter or generator. My 120V shore power connection would not do and my current inverter that is tied into the truck batteries will not be sufficient.

What's wrong with the shore power connection? What about the current inverter is insufficient?

SIBERNUT · November 25, 2016

Here in MD, you need 4 out of 7 qualifiers to become a "Motorhome". Shore power, NOT a generator is one of them.

Shore power, toilet, cooking, sleeping, heating/cooling, pressure water w/sink & refrig I think. You pick the 4 that you like & fill out a MVA form, period.

rpsinc · November 25, 2016

Saw your sketch. A 3000W genie is pretty big for what you are trying to accomplish. A little 1000-1500W inverter style should do everything you want inside and hopefully satisfy the
"authorities". Sadly, asking them tehcnical questions is often futile. They arent technical people, they are rules and code people.

I dont understand how an inverter tied into your truck batteries isnt sufficient. That is what an inverter is SUPPOSED to do. Plus it would do all you want for the kids and only while driving. Might be good to install a disconnect or solenoid wired to the ignition so that you dont drain batteries in an accidental TV left on situation.

RandyA · November 26, 2016

Brad, nothing wrong with running a generator when cruising down the road. Last year on the way to Florida my inverter died. I ran the 3100W truck mounted inverter genny for two days of travel to keep the fridge cold. As noted above a 3KW inverter genny is overkill for what you want to power while driving. But, if you do not have a genny for your trailer it is nice to be able to pull the power from the truck mounted genny - which we do often in warmer weather when we stop to rest or have a snack in the trailer as we can run one of the rooftop A/C units and the bigger microwave. If you go with a genny be sure to get one with electric start and a wireless remote. Without those features it will be a real PITA. You may find that you will have to disconnect the low oil shutdown circuit on the genny while driving. Inside the engine crankcase is a float switch that often faults to the low oil shut down position due to movement, braking, hills, curves, etc. A typical gasoline inverter generator usually means carrying extra fuel in plastic gas jugs. If you stop for diesel for the truck you will probably need to move to another pump to get genny gas - another PITA.

The inspector not allowing you to count an inverter that runs off the truck batteries is a new one for me. I doubt that the requirement for yet another independent battery and inverter has any language as to the minimum wattage or battery capacity. Thus, you should be able to stick one of those small portable battery jump packs in the truck and plug in a 25 watt cig lighter socket inverter to meet the requirements :rolleyes: .

Your connection diagram for using a transfer switch is typical of what is usually installed. As I've noted in other threads it is safer NOT to have a neutral and grounding buss interconnected. Keep this in mind if you install a generator or another inverter - many of these units have an internal bond that negates the isolation. You will want a "floating neutral" on your aux power source.

Seniramsu · November 26, 2016

The people that you need to talk to would be the inspector. What are their requirements?

"separate 120V system," I was told I needed an inverter or generator. My 120V shore power connection would not do and my current inverter that is tied into the truck batteries will not be sufficient.

What's wrong with the shore power connection? What about the current inverter is insufficient?

That's who I spoke to was the inspector. That's the reason I'm looking at adding another power solution. Was told by the inspector that the shore power wouldn't qualify and the inverter must be on it's own batteries. Didn't want to argue with the guy that's going to approve my hdt as a motorhome.

Here in MD, you need 4 out of 7 qualifiers to become a "Motorhome". Shore power, NOT a generator is one of them.

Shore power, toilet, cooking, sleeping, heating/cooling, pressure water w/sink & refrig I think. You pick the 4 that you like & fill out a MVA form, period.

I'm in Missouri.

Saw your sketch. A 3000W genie is pretty big for what you are trying to accomplish. A little 1000-1500W inverter style should do everything you want inside and hopefully satisfy the

"authorities". Sadly, asking them tehcnical questions is often futile. They arent technical people, they are rules and code people.

I dont understand how an inverter tied into your truck batteries isnt sufficient. That is what an inverter is SUPPOSED to do. Plus it would do all you want for the kids and only while driving. Might be good to install a disconnect or solenoid wired to the ignition so that you dont drain batteries in an accidental TV left on situation.

I tend to over do solutions........thought was if I was going to put something in I would put in more than I need. So might just end up going with a smaller inverter charger and a couple batteries for now. Didn't ask the inspector anything just had him go over the list and when I said I had shore power......he said that won't pass......then told him I have an inverter.......he asked if it was tied into the truck batteries....it is...he wouldn't pass that. So willing to do whatever it takes for him to sign off on this.

Brad, nothing wrong with running a generator when cruising down the road. Last year on the way to Florida my inverter died. I ran the 3100W truck mounted inverter genny for two days of travel to keep the fridge cold. As noted above a 3KW inverter genny is overkill for what you want to power while driving. But, if you do not have a genny for your trailer it is nice to be able to pull the power from the truck mounted genny - which we do often in warmer weather when we stop to rest or have a snack in the trailer as we can run one of the rooftop A/C units and the bigger microwave. If you go with a genny be sure to get one with electric start and a wireless remote. Without those features it will be a real PITA. You may find that you will have to disconnect the low oil shutdown circuit on the genny while driving. Inside the engine crankcase is a float switch that often faults to the low oil shut down position due to movement, braking, hills, curves, etc. A typical gasoline inverter generator usually means carrying extra fuel in plastic gas jugs. If you stop for diesel for the truck you will probably need to move to another pump to get genny gas - another PITA.

The inspector not allowing you to count an inverter that runs off the truck batteries is a new one for me. I doubt that the requirement for yet another independent battery and inverter has any language as to the minimum wattage or battery capacity. Thus, you should be able to stick one of those small portable battery jump packs in the truck and plug in a 25 watt cig lighter socket inverter to meet the requirements .

Your connection diagram for using a transfer switch is typical of what is usually installed. As I've noted in other threads it is safer NOT to have a neutral and grounding buss interconnected. Keep this in mind if you install a generator or another inverter - many of these units have an internal bond that negates the isolation. You will want a "floating neutral" on your aux power source.

I do have a generator for the camper......like the thought of having something for the truck if we decide to just take it and leave the camper at home for a short weekend trip. Wouldn't have to worry about batteries not being charged if we were somewhere without power. Some good points I didn't think about while going down the road with the generator. This is why I posted out here to pick the minds of those that know.

Yes, was a surprise to me as well as this wasn't something I was planning to do right away. I even thought of just adding a single battery I had around the house and just moving the wires over to it to get past the inspection.....just figured if I was going to do something I would over do it!

Thank you for the information on the floating neutral, I'll be sure to keep that in mind.

rickeieio · November 26, 2016

First, it sounds like the inspector is being a thorn in your side, possibly by intent. I seriously doubt there is a regulation that says the inverter can't run off truck batteries, or that shore power is not approved. Look at all the lower priced motorhomes out there which may not even have an inverter, but have shore power.

So, how many batteries do you have? Will the truck start okay on two? If you have 4 batteries, re-configure your cables to have two run the truck, and the other two supply the inverter. Get it inspected, and change it back.

billr · November 27, 2016

First, it sounds like the inspector is being a thorn in your side, possibly by intent. I seriously doubt there is a regulation that says the inverter can't run off truck batteries, or that shore power is not approved. Look at all the lower priced motorhomes out there which may not even have an inverter, but have shore power.

So, how many batteries do you have? Will the truck start okay on two? If you have 4 batteries, re-configure your cables to have two run the truck, and the other two supply the inverter. Get it inspected, and change it back.

Yup!!??

Dollytrolley · November 27, 2016

First, it sounds like the inspector is being a thorn in your side, possibly by intent. I seriously doubt there is a regulation that says the inverter can't run off truck batteries, or that shore power is not approved. Look at all the lower priced motorhomes out there which may not even have an inverter, but have shore power.

So, how many batteries do you have? Will the truck start okay on two? If you have 4 batteries, re-configure your cables to have two run the truck, and the other two supply the inverter. Get it inspected, and change it back.

Oh comrade....you must stand back and consider your fellow comrades.....

In the stone age, in a far away land I found myself charged with herding a OLD airplane around that was built in Poland... It was ugly and really odd on a lot of ways but it came with a Ruskie-engineer (mechanic) and he had to ride in the darn thing so he had a inventive to keep it running fairly well...

This thing had engines with air powered starters....ugly...so...if the air tanks ran down you had two choices, first choice was to find a aircompressor ....or the last choice...use the explosive charge shellscharge system to turn the engines over .....grim choice.

I ask the Ruskie-engineer who in heck thought up the lame shotgun starting system and he would grin and said, "well COMRADE, it gets verrrry COLD in the Motherland and we have a lot more gunpowder than airplane batteries AND the chief Comrade designer's brother was the manager of the starter shell plant... COMRADE......

So COMRADE, does the "INSPECTOR'$ brother own the Battery store or manage the inverter factory.... COMRADE....we do know his brother has nothing to do with shore power.

Welcome to design by.... COMRADE'$....

I was in China during part of the Bank bail-outs and our driver Mr Chin would listen to the news about the US Banks being mailed out by uncle Sam and he would say...."oh Mr Mikeee, us in China try that and it Does NOT work,fo not do what we do".

Now we have Comrades here telling us to build our trucks their way... COMRADE..

We used to joke about the Russian's ...now the joke is on us.....sadly.

Drive on.....(Keep the "Inspector" ... happy)

EDIT: Ok I was a bit grumpy with COMRADE remarks and I am assume that the inspector is doing his job as he sees fit or perhaps his or her boss($) see their mission.

In my grumpy fashion I am pointing out that "Dictating" TWO AC electrical systems in the RV can involve grave consequences if not engineered AND installed properly...so...IS the "Inspector" really qualified AND willing to take the effort to truly assure that the "dictated" secondary AC system SAFE...

Seems the public is fairly safe from the operation of factory installed Volvo electrical systems .... I suppose that could change if one installs too many "dictated" systems....

Ok I am off to get some Dr Pepper then all will be good again

Sorry for the grumps...

Drive on.....(Grumpy... not good)

rickeieio · November 27, 2016

Oh Comrade D/T, it wasn't just our friends from Russia and Poland who used gun powder to start their planes: https://en.wikipedia.org/wiki/Coffman_engine_starter

Star Dreamer · November 28, 2016

I figured Phoenix would chime but I couldn't resist. They also used them in the original movie Flight of the Phoenix. Not sure about the remake

Dave

Dollytrolley · November 28, 2016

Oh Comrade D/T, it wasn't just our friends from Russia and Poland who used gun powder to start their planes: https://en.wikipedia.org/wiki/Coffman_engine_starter

Oh Rickooo don't get me started on inertia -starters on some of the old birds ...being a old farmer you would be right at home cranking the flywheel up just like the old hand crank cream separator on the farm.....

When I was a kid one of grumps drivers had a couple of surplus B-17 converted to retardant applicators for fire fighting some times a starter would fail and I would climb the step ladder to put the prop cuffs and then I would get to drive the Jeep to pull the rope that pulled the prop blades around to start the engine(s).

Great fun.... pretty sure if you had a kid do that today you would be in jail with Buba long time.....

Drive on.....(don't throw the starter shells in the campfire...)