Residential Fridge/Inverter Install

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Bobtop46

Well-known member
Joined
Mar 11, 2011
Posts
735
Location
Dunnellon FL
I finished prepping the space for delivery of the residential fridge and all the work under and behind the kitchen cabinets. 

The Fridge prep:  Removed old fridge (Dometic NDR1292) The space underneath was completely empty.  Removed mounting shelf and frame work, capped off and removed gas line, removed insulation on the sides, installed new outlet, cut and capped 12v DC wires and put back in wire loom, removed upper and lower RV fridge vents, used aluminum diamond back to cover outside vent holes (triple caulked), and used 3/4" insulation sheets to fill inside holes.

Inverter install: The inverter will go under the space shown in the pictures here.  I moved the converter outlet, moved a junction box to under drawers, moved converter over a little, installed 2 prowatt relays connected to two 15 amp breakers, made short extension cords (2 FT) to go down the hole I drilled in the floor, installed re-purposed plastic tube in the whole to protect wires (from old fridge gas line), installed inverter remote, and ran the cable for Trimetric-RV battery monitor.

In the pictures, Behind my breaker box (inverter1)- new whole in floor left front, relays center front, extra cable for inveter and battery monitor coiled up in the back
Under drawer (inverter2)- Moved outlet and junction box

Next up is to actually install the inverter down below.
 

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Rene T

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Joined
May 20, 2011
Posts
17,344
Location
Farmington NH
When I was looking for a residential fridge, I wanted one with the condenser on the back of the fridge. I left the side vents in place and just stuffed insulation on top, along the sides and the bottom of the fridge, This kept any drafts and bugs from the vent covers out of the RV.
 

QZ

Well-known member
Joined
Jul 17, 2017
Posts
556
Nice job and very neat. That's how I installed my whirlpool 10.7 with rear coil. I closed the vents and provided the required clearances on the top and sides. Trimetric is a great addition.
 

Bobtop46

Well-known member
Joined
Mar 11, 2011
Posts
735
Location
Dunnellon FL
Update, I have the inverter installed and fired up works great.  Trimetric works awesome also, I hooked up the optional wire to my engine battery, which allows me to monitor the voltage.  I can see when the converter charges it also. voltage goes up to 14.4 then back to 12.9v, after charging. 

We also took delivery of the fridge today and put it in the hole to see how it fit.  Pictures attached.  Now I need to take it out back and figure out how I want to secure it in the hole to keep it from rolling out going down the road. I have several ideas and must use a combination of all of them.

The only disappointment is I shouldn't have trusted the labeling on the breaker panel.  One of the circuits I picked to run off the inverter was "dining room/bedroom"  The dining room works and that was the goal, power the new fridge.  The bedroom doesn't and really is power off the bathroom breaker.  Not really a big deal as this is really only a concern going down the road.

I also overhauled my crap show of a battery well.  3 batteries sitting in open trays on 2 steel bars right behind my passenger front tire.  Lots of dirt and sand plus corrosion.  I relocated my engine battery and added 2 more Trojan T105s, for a total of 4.  I ground off the rusting old battery trays, wire brushed everything and repainted.  I installed 2 more metal bars on each side, and covered with diamond plate aluminum.  I left a 1/2" gap at each end for ventilation.  The metal compartment also has a 2x6" hole in the back near the top.  Then I mounted the batteries in these:  https://www.amazon.com/gp/product/B003VAUG5A/ref=oh_aui_detailpage_o01_s00?ie=UTF8&psc=1

to the diamond back using u-bolts around the original metal bars.  I meant to take before and after pictures of this but forgot the before pics.  The after don't look like much since all you can see is the side of the 2 battery cases. 
 

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QZ

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Joined
Jul 17, 2017
Posts
556
Good to hear that. You're doing a beautiful job and you'll love the resi.
 

Bobtop46

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Joined
Mar 11, 2011
Posts
735
Location
Dunnellon FL
It is a  Samsung RF18HFENBSG-2 17.5cf.  I measured and looked around carefully.  When it was delivered the fridge doors had to be removed to get it in the RV door.  I got this from Lowes that assured me they would deliver it inside the RV.  The delivery guys hemmed and hawed, but followed thru.  Home Depot said they would only deliver it to the door. 

Once we got the doors back on it, we just slide it into place like you see in the pictures.  Weighs 1 pound more then the Dometic did, but I easily removed 1 pound of frame work the old one sat on.

I also required a french door fridge because when the slide is in I still wanted to be able to open at least one of the doors.  We tested it last night and the right door opens fully and the left one about half way, which was about the same for the Dometic.  The fridge could also not stick out to far, because we still wanted to be able to partially open the bathroom door and slip in when the slide was in.  This was the only fridge that met all the criteria for height, width, weight, door size, depth, slide in requirements, and still able to get it thru the front door.
 

Bobtop46

Well-known member
Joined
Mar 11, 2011
Posts
735
Location
Dunnellon FL
Final update:  I got the fridge secured in the hole.  Used 3 methods.  First I put in a board across the top to be as close to the top of the fridge as possible to keep it from tipping out (pic 1, bit dark sorry). Second I added a couple of small 1x2 in the back to create a standoff distance from the back for ventilation purposes and because the fridge actually sat too far back in the whole.  I had left part of the frame work at the bottom for a tighter fit.  I covered all the 1x2 with a cut up pool noodle, sliced in half long ways.  I did this so the fridge wouldn't rub on wood and make for a better fit. The new fridge has two vents in the back on the bottom, one the left side and one on the right.  I had to use a putty knife on one side to hold the pool noodle back when pushing it in. (pic 2).  Lastly I removed the black leveler feet off the front and took to the store to find bolts in the matching thread pattern (M8 x 1.25)  I slid a piece of trim from old install under the bracket for levelers ( snug fit not lifting or pulling down) drilled pilot holes in it and floor, then drove (3) #14 screws thru the board and carpet into the plywood below (below that is foam insulation) Then I took my bolts, threaded them from top down where the levelers were and drove those thru the board and into plywood floor.  I was pleased to find out that the lower front trim still fit.  (pic 3)

This job is complete.
 

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1anjl

Active member
Joined
Sep 7, 2018
Posts
35
Location
Western Washington State
Wow nice job! I have a newbie question....the inverter is so that the fridge will run off electric while you are traveling on the road? Just wondering if I switch out my fridge to residential fridge in a TT that won't be traveling... would I need inverter too?
 

QZ

Well-known member
Joined
Jul 17, 2017
Posts
556
1anjl said:
Wow nice job! I have a newbie question....the inverter is so that the fridge will run off electric while you are traveling on the road? Just wondering if I switch out my fridge to residential fridge in a TT that won't be traveling... would I need inverter too?

No, you won't need one because you will be running on shore power only. You could still move the RV or travel but just have to leave the fridge closed. It will stay cold enough for several hours. Some people install residential and plug it in at home to cool down then load up and travel to local spots and plug back in.
 

Rene T

Site Team
Joined
May 20, 2011
Posts
17,344
Location
Farmington NH
1anjl said:
Wow nice job! I have a newbie question....the inverter is so that the fridge will run off electric while you are traveling on the road? Just wondering if I switch out my fridge to residential fridge in a TT that won't be traveling... would I need inverter too?

NO you would not as long as your RV will be plugged into shore power.
 

Bobtop46

Well-known member
Joined
Mar 11, 2011
Posts
735
Location
Dunnellon FL
1anjl said:
Wow nice job! I have a newbie question....the inverter is so that the fridge will run off electric while you are traveling on the road? Just wondering if I switch out my fridge to residential fridge in a TT that won't be traveling... would I need inverter too?

The answers above are correct, you will not need an inverter while plugged in at a campground and the trailer doesn't move. One other thing to consider is that you will save money with a residential fridge on electricity, if you are metered at the campground.  The RV fridge boiler on electric runs most of the time at about 400 watts.  My new residential runs at about 100 watts when on cycle and 0.5 watts when off cycle, depending on how often you are in the fridge.  This is a big electric saving.  Depending on how reliable the electricity is at your camp site an inverter would run it if the power goes out, until your batteries get low, but might not be worth the expense.
 

Bobtop46

Well-known member
Joined
Mar 11, 2011
Posts
735
Location
Dunnellon FL
Update:  We took our first test run with new upgrades of inverter, Samsung fridge, and replaced airbags.

  The airbags worked great and hold air with no problem.  I need to experiment with air bag pressures to find one we like I started with 50 psi and think I might try 60.  Does anyone have a pressure they use on W22 frame for front and rear?

The inverter and the fridge.  Things work but not as well as I hoped.  The fridge runs fine when power is supplied and the DW loves it.  Here is my issue with the setup and need help.  See diagram above in earlier post.  I did not change the diagram but all the load negative wires go to one side of the shunt, only one negative goes from other shunt to negative post of battery.
http://www.rvforum.net/SMF_forum/index.php/topic,115752.msg1046557.html#msg1046557
1. When AC is applied by generator or shore power the inverter is by passed and the fridge runs off either one (tested).
2. When there is no AC available the fridge runs off the inverter (tested), about 100 watts on cycle.
3. When attempting to go down the road, engine running, the GFCI on the output side of the inverter trips on the first fridge on
cycle.  I have unplugged everything on the circuit except the fridge.  I originally had two plugs, plugged into the inverter but unplugged the other one.  It goes to other outlets that have nothing plugged in.  I removed it from the problem to eliminate it as a source of the problem.  I also tried moving the plug for the fridge circuit to the other plug on the GFCI with the same result.  The circuit the fridge is on has no GFCI in line. This only happens when the engine is running.  I have a Trimetric battery monitor.  I can see the alternator providing 14.4v to both the engine battery and the house battery.  My battery bank is new and been on charge with Intellec converter/charger since installed. I can watch the voltage go from 14.4 to 13.7, to 13.3 after a test discharge of 25%.  We started this trip with fully charged batteries.  I traced the engine battery ground and it goes to the engine block.  The rest of the 12v battery grounds go to a stud on the frame, which I cleaned and added the inverter ground too. and torqued to spec.listed in the inverter manual.  I also rechecked all the torques on the battery post to spec. listed in the manual.  All battery wiring is 2/0.  3 FT from inverter to 250 amp fuse on the + side and 3 FT to the 500 amp shunt on the negative side.  18 inches from fuse and shunt to the battery.  I get no faults of high voltage or low voltage, no high temp, no overload, no low battery alarms.  No alarms or faults just a tripped GFCI.

Why does my inverter GFCI only trip when the engine is running.

Would moving the ground to the inverter make a difference, I don't see how or why it would? 

 

Gary RV_Wizard

Site Team
Joined
Feb 2, 2005
Posts
73,533
Location
At our Silver Springs FL home
The GFCI has nothing to do with DC power, so changing grounds or other 12v connections can't have any effect. A GFCI trip means that 120v power on the hot (black) wire in that circuit is going somewhere other than the 120v neutral (white) wire.  GFCI logic is simple - it measures the outgoing amps and the return amps on the neutral wire. If they are not identical, it trips because there is a short somewhere. Possible problems with the DC feeding the inverter are not relevant.

The only thing I can conceive of is that starting the engine (ignition key on) is activating some other gadget or circuit that is either creating a short n the 120v wiring from the inverter GFCI or activating another inverter that feeds power to the same circuit.  Diagnosing that is going to take some creative thinking, but you need to be looking at the 120vac side, not the DC side.  What does ignition on activate that might have an effect?

One thing to try: instead of actually starting the engine, just turn the ignition ON. See if the GFCI trip occurs.
 

solarman

Well-known member
Joined
Feb 8, 2018
Posts
417
Location
Texas
Bobtop46 said:
Update:  We took our first test run with new upgrades of inverter, Samsung fridge, and replaced airbags.

  The airbags worked great and hold air with no problem.  I need to experiment with air bag pressures to find one we like I started with 50 psi and think I might try 60.  Does anyone have a pressure they use on W22 frame for front and rear?

The inverter and the fridge.  Things work but not as well as I hoped.  The fridge runs fine when power is supplied and the DW loves it.  Here is my issue with the setup and need help.  See diagram above in earlier post.  I did not change the diagram but all the load negative wires go to one side of the shunt, only one negative goes from other shunt to negative post of battery.
http://www.rvforum.net/SMF_forum/index.php/topic,115752.msg1046557.html#msg1046557
1. When AC is applied by generator or shore power the inverter is by passed and the fridge runs off either one (tested).
2. When there is no AC available the fridge runs off the inverter (tested), about 100 watts on cycle.
3. When attempting to go down the road, engine running, the GFCI on the output side of the inverter trips on the first fridge on
cycle.  I have unplugged everything on the circuit except the fridge.  I originally had two plugs, plugged into the inverter but unplugged the other one.  It goes to other outlets that have nothing plugged in.  I removed it from the problem to eliminate it as a source of the problem.  I also tried moving the plug for the fridge circuit to the other plug on the GFCI with the same result.  The circuit the fridge is on has no GFCI in line. This only happens when the engine is running.  I have a Trimetric battery monitor.  I can see the alternator providing 14.4v to both the engine battery and the house battery.  My battery bank is new and been on charge with Intellec converter/charger since installed. I can watch the voltage go from 14.4 to 13.7, to 13.3 after a test discharge of 25%.  We started this trip with fully charged batteries.  I traced the engine battery ground and it goes to the engine block.  The rest of the 12v battery grounds go to a stud on the frame, which I cleaned and added the inverter ground too. and torqued to spec.listed in the inverter manual.  I also rechecked all the torques on the battery post to spec. listed in the manual.  All battery wiring is 2/0.  3 FT from inverter to 250 amp fuse on the + side and 3 FT to the 500 amp shunt on the negative side.  18 inches from fuse and shunt to the battery.  I get no faults of high voltage or low voltage, no high temp, no overload, no low battery alarms.  No alarms or faults just a tripped GFCI.

Why does my inverter GFCI only trip when the engine is running.

Would moving the ground to the inverter make a difference, I don't see how or why it would?

firstly, the inverter should not be bonded to the chassis, it should have a return to the negative distribution bar that you installed ( right ? ) that is fed from the shunt.
secondly, in your other post, the diagram shows a chassis bonding on the negative terminal of the battery.. the chassis should be bonded at the hot end of the SHUNT, and only the shunt, the negative terminal of the battery should only have one thing connected to it and that's the other end of the shunt.

correct the wiring issue first then retry your experiment
it could be odd chassis return currents upsetting the GFCI through the ground..


 

John From Detroit

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Joined
Apr 12, 2005
Posts
24,798
Location
Davison Michigan
The diagram you linked to you have (Simplified showing one side)

Main breaker box----- Outlets---- INverter----- Batteries

SHould be
Main breaker box. dedicated branch breaker ----Inverter---_Batteries.

Inverter----- Sbbpanel----Outlets

The inverter should have an internal transfer switch. if not you need a 2nd (and possibly 3rd) transfer switch for the outlets with the inverter taking the place of shore power and the dedicated 30 amp line from the main box taking the place of the Generator on that added transfer switch.

My "job" of the day today was upgrading my inverter.. When I put in the Freedom XC-2000 I had to use the 12 volt leads (4ga) I had on hand. they are double Zero's now.


 
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