Inverter installation

[hank_moses]

Hey everybody. I'm looking for the experts to weigh in on the way
I plan on installing a 1500 watt inverter that will be dedicated to
running the new residential fridge that we just installed. Below is a
sketch of how we plan to set everything up. Seems like it would work.
Anybody's 2 cents, er.. I mean 2 $ (due to inflation), would be appreciated.

 

[hoosierguy]

That should work fine as long as your coach is connected to shore power or when you are towing. Make sure the tow vehicle wiring is actually aloowing for charging the coach batteries. When neither condition applies, you will have limited time until the batteries are discharged to a point that the inverter does not have sufficient battery input to maintain the output to the refrigerator.

 

[mhs4771]

You would be much better off with an Inverter that has a pass-through for 120 shore power. Our Inverter has two inputs: 12VDC and 120VAC, with an internal Transfer Switch. When on Shore Power 120 is passed through the Transfer Switch to the Fridge and the Inverter goes into a Standby Condition. When Shore power is disconnected the Inverter kicks in and supplies 120V through the Xfer Switch to the Fridge.
The setup you have drawn will be drawing power out of your Batteries all the time, granted the Converter will be charging the batteries but it makes for an inefficient setup. But if you already have the Inverter, I guess you use what you have.

 

[hank_moses]

That should work fine as long as your coach is connected to shore power or when you are towing. Make sure the tow vehicle wiring is actually aloowing for charging the coach batteries. When neither condition applies, you will have limited time until the batteries are discharged to a point that the inverter does not have sufficient battery input to maintain the output to the refrigerator.

Thank you guy. I recently purchased a 2024 ram 3500. Traded in my 2011 F-450.
I know the ford did supply power while towing, but I will connect ram to see if it
charges while towing.

Regards

 

[hank_moses]

Thanks Michelle & Ann.
Yes, I have already purchased the inverter with just the 12 volt input. I was
simply trying to keep things simple. I did add a third battery to keep charge
up, and the fridge should be the only draw on the batteries while moving.

Regards

 

[XCMARK]

I will jump in also , in my case I have found the truck is really only able to supply about 4~6 amps at 12.6 volts. The voltage drop from the truck wireing and the trailer has proven to really limit the current at a high enough voltage its suitable for the batterys to accept a charge. I would suggest installing a Victron Orion in the trailer close to the battery. Its able to take 10 volts DC and boost it up to 13.6~14.6 volts DC and put out 18 amps at that voltage.
https://expion360.com/products/vict...MIwK2Lgv7WiAMVrVpHAR3JxSEpEAQYFyABEgJVIPD_BwE

I would also suggest a Victron multi plus II inverter. Its wired in line with your incoming power cord and is able to supply 3000 watts at 120 volt to your RV from the battery and its able to supplement utility power, say you're a friend's house and you have a regular outlet at 15 amps. Thats no problem the inverter supply's an additional 3000 watts if you want to run the 2nd AC from the batteries. Once the load drops down below the amps you set it to (from 9.5 amps up to 50 amps) the battery charger comes back on and starts charging. We can travel down the road turn on our AC unit via the Micro air Bluetooth APP and have the AC running hours before we pull into our campground. I know this is more money but the forward compatibility is unlimited! Adding Solar , Lithium battery ( can be programed for any charge voltage) ,multible inverters to run two AC units is all possible . happy to help if your interested. Honestly the first step is to install a battery monitoring system , You dont want to use the meter the trailer has built into the control panel those things are very poor at best.
https://www.amazon.com/Victron-Ener...9&psc=1&mcid=d77367108e483425b5effe1c94a52e49

https://www.amazon.com/Victron-Ener...27024245&sprefix=multiplus+3000,aps,57&sr=8-8

 

[hank_moses]

Thanks Mark

I could check and calculate voltage drop based on RV and truck wiring, but
for peace of mind, and inexpensive cost of the booster, I totally agree with
you. Also the batt monitor is a must. Just ordered both of those. Like I
stated above. I was just trying to keep things simple by installing a pure sine wave inverter to be dedicated to the fridge only.
As far as the 3000 watt inverter, sounds like a great plan for me. I used to keep my fingers crossed every time I hooked into shore power at some rv
park because of fluctuations in the parks power, so I installed an EMS Smart
surge protector, and am wondering would the 3000 watt inverter go before
that system or someplace after.
Thank for that great info. I wished RV manufacturers would consider these as
options they could provide to customers.
BTW I've recorded 89 volts on the digital monitor at one RV park I stayed in
once when the system shut power to RV to protect it. That event lasted over an hour. Couldn't wait to get outta there.

Regards

 

[XCMARK]

With Regards to the 89 volt lock out , Do you have an auto transformer to boost the voltage? The Hughes auto transformer can boost up to 12 volts and it adjust the level of boost in two steps. We stay at a place in Maine that has voltage drop problems on hot days. I end up using solar and my inverter to run the AC, once the sun starts to get low in the sky then swap back to utility power. 89 Volts is very low and should avoid running anything expensive ( AC , Refrigerator, TV, ECT.)

 

[hank_moses]

Mark...

I do not have a booster for DC voltage. I'm currently trying to install the new
"Victron" 12 -18 booster for the truck connection to RV for traveling. I have
RV'ed for about 15 years and never experienced a voltage drop like I stated
above, which happened in Louisiana. Installing a DC voltage booster for the
whole 12 V RV system probably would be something that I would have to
consider and research thoroughly. The 3000 W Victron multi plus II inverter
that you suggested above is what I'm currently researching at this time. As
far as setting up in an under performing RV in the feature. If I see fit, I will
simply pull up stakes and move.
Still running wire and conduit for the fridge inverter. It's kind of complicated
trying to mount the 1500 W inverter in the space above the fridge, because
you then have to run the conduit and conductors from the expansion keepers
on the slideout then into conduit towards the front and into the battery
compartment. Not such an easy job as I thought it would be, but I'm almost
there. Also running "Victron" batt monitor feed at the same time to mount
display above fridge.
Thank you for the information that you have been providing, it's helped me
greatly.


Regards

 

[XCMARK]

The charging voltage drop issue is a big deal when you consider multiple day in a row traveling and NOT connecting to a generator or shore power over night when you have a residential refrigerator. It's not a issue with propane RV style refrigerators because the power demands are less then 3~5 amps at 12 volts. Residential 120-volt refrigerators draw 3~5 amps at 120 volts, ten times the amount of power when they run. Most owners 5 years ago didn't have any way to really measure the battery state of charge , we just ran with the old manufactures voltage gauge and called it good. Today's RV have hydraulic legs that need 50~70 amps at 12 volts DC and we sometimes wonder why the system has problems ( low voltage on the 12-volt DC controls) or sometimes the slide outs don't work correctly when we are not plugged into park power. Sometimes its just weak battery's.

I had 200-amp hours battery that were in good shape back a few years ago, my refrigerator without power on the RV would run the battery's down to 50% in about 16~20 hours depending on the temp inside the RV. Driving and a overnight without park power I was down to 30% battery by the end of the 2nd day of traveling with just the truck alternator charging the RV. With the Victron 18-amp charger installed I am unlimited back-to-back days traveling, its just enough of a Constance charge that i park the truck at 5PM and the next day before we get on the road the battery are about 75% and by 1pm are full charged again.

For what it's worth I have been an electrician for 40 years .

 

[hank_moses]

Good morning Mark.

I just happened to be logged in and read your post. I totally agree with you
on the 3000 W inverter, and plan on installing one. I am not an electrician
and I have to research electrical items before I install them as I'm a " do
it your selfer". I could afford to have an installer put in these items, but don't
trust installers nowadays to install my stuff correctly. Sure guarantee is good,
but I believe having to drag RV back to shop for rework is not worth it to me
when I can do just as good a job plus acquire a better understanding and be
able to troubleshoot malfunctions in the systems that I install myself.
I'm Still researching 3000 watt booster........
So far I have replaced both AC units, Overhauled the furnace, installed new
gate valves on the black and gray tanks, changed new seals on all three
slides, installed four G rated 14 ply tires, almost finished installing new carpet
that was sunfaded in the living room, Replaced all pluming, and fan vents,
removed old sealant from front and rear RV caps and resealed, and changed
out hydraulic seals on legs as well as flush old hydraulic fluid to replenish,
and a bunch of other thing to many to keep on listing. I have never did these
things before, always left it to "experts at the RV shops????" HUMPH.
As I stated above I'm still installing the fridge inverter, The Victron battery
monitor, and the 12 V DC booster. Just having trouble trying to find out
where the wires are on the RV to hook to the ''input'' side of the booster.


Regards

 

[hank_moses]

Mark..

Re-reading your last post. I am at this time attempting to install the
Victron 12V 18AMP booster feeding power from the towing truck. Just
want to make sure that is clear. Also trying to find out which wires on
the RV that I should plug into the "INPUT" side of the booster.

Regards

 

[XCMARK]

Mark..

Re-reading your last post. I am at this time attempting to install the
Victron 12V 18AMP booster feeding power from the towing truck. Just
want to make sure that is clear. Also trying to find out which wires on
the RV that I should plug into the "INPUT" side of the booster.

Regards

the cord that plugs into the truck typically has a splice up at the pin box. I would bet you find the battery positive on the cord to be a 12-gauge wire that is spliced to a red #6 wire that goes to the bus bar that feeds the hydraulic motor for the landing gear. That RED #6 goes to the input side of the Victron. The red #6 from the truck side will only connect to the Victron Input, you output will share the ground on both input and output. the output from the Victron should be fused right at the Victron and should be a #10 wire that connects to the battery as close as possible. Depending on your battery type you will need to set up your charge voltage on the output side. you can do this with a smart phone and the Victron APP . I used the parking lights as the "turn on trigger" to the Victron. The voltage drop is too high to set up the Victron for 14.7vdc running trigger. I have to turn on my parking lights to turn on the DC to DC charger , not a big deal I drive when towing with parking lights on anyways. The

 

[hank_moses]

Mark.

After examining the wires on the pin connection from the Ram that I
will be using to tow, I'm pretty sure that I am possibly gonna have
an over current issue with that type of setup.
What I'm planning to do is to run 4awg wire from truck battery to
back bed of truck near rv connector and install an Anderson connector,
then find some way to run conductors to the booster that I am
mounting in the batt compartment. Seems like the simplest way of doing
things.
I believe the wires on the 7 pole connector are only meant to provide
power to rv running and brake lights as well as electric brakes.
A question for you though. Would you hook the NEG cable to the farthest
battery terminal from the output of the booster and the POS terminal to
the opposite end of the parallel batteries so as to balance charge thru all
3 batteries? Also what size fuse at the booster on the POS before "input"?


Regards

 

[XCMARK]

My GM trucks has a wire for the 12 volt positive and Negative that are slightly larger then a 12 gauge , I dont think they are #10. The wire that comes from the trailer to the truck plug, My old one had a #14 for 12 volt positive and a #10 for the ground. I just replaced that with a new bergman heavy duty (severe weather Blue cord) , it has #10 for positive and negative ground and #12 for brakes. The GM trucks have a 30 or 40 amp maxi fuse on the trailer plug 12 volt line. If your Ram has a 30+ amp fuse on the truck side, I would just use that and skip the Anderson plug and extra wiring. It's just one more thing to install the next time you swap trucks or need someone to move your trailer. That's why I only have the 18-amp output charger installed in my RV. I see 10.4~ 10.9 volts on the input side when the Victron is bulk charging at 18 amps. Figure about 280 watts on the input side, that 27 amps at 10.4 volts while is putting out 18 amps at 14.7 volts.