Have You Installed a Residential Fridge and Inverter in TT?

westend wrote:
For reference: I run a small dorm fridge with a 300AH bank and a Xantrex 1000W inverter. It draws 80 w at a 1/4 duty cycle in summer ambient temps. A larger residential fridge will use a bit more power but not much. The locked rotor draw is the reason to use a 1000W+ inverter and the Tripplite should overcome that easily. 4 to 5 hrs, of run time should be easily accomplished with two 12V batteries and the charging of the vehicle.

BTW, you won't miss solar until you have some.:B

Actually interestingly enough the compressor current draw of a 1.2 cu ft dorm fridge is nearly identical to my 10 cu ft apartment size fridge I used. Pretty much all fridges use the same compressor which draws 1A-1.2A run current.

What I have observed however is the small "dorm" fridges have LESS insulation than the larger apartment size fridges.

I compared a 1.2 cu ft fridge I have in my basement and my apartment fridge when I was initially testing my conversion setup..

The smaller dorm fridge was drawing 90W and the apartment fridge was also drawing 90W. Basically a dead heat..

BUT, the dorm fridge compressor would run for 20 minutes then shut off for TEN minutes so it had a duty cycle of 40 minutes ON and 20 minutes OFF for every hr.

The apartment fridge ran 20 minutes and was OFF 40 minutes.

Both were operated side by side in the same temperature conditions.

If you closely look at a dorm fridge you will notice that is has about 3/4" of insulation.

The apartment fridge I have looks to have at least 2 inches of insulation.. Makes a huge difference.

Couple that with my Tripplite inverter with the load sense and now you no longer have to account for wasted power due to the inverter idling while the compressor isn't running!

There have been folk who have been able to get a home fridge to run from 800W inverters but I do think that they are pressing things a bit.

A 1000W Tripplite should have plenty of surge capacity to reliably start the fridge. However you MUST use HEAVY ga wire on the 12V side AND keep it short. Otherwise the wire will drop too much of the 12V and the inverter will be close to low voltage shut off during the start up surge.

For reference: I run a small dorm fridge with a 300AH bank and a Xantrex 1000W inverter. It draws 80 w at a 1/4 duty cycle in summer ambient temps. A larger residential fridge will use a bit more power but not much. The locked rotor draw is the reason to use a 1000W+ inverter and the Tripplite should overcome that easily. 4 to 5 hrs, of run time should be easily accomplished with two 12V batteries and the charging of the vehicle.

BTW, you won't miss solar until you have some.:B

BuffaloIndian wrote:
Thanks for the link Gdetrailer! Muchos gracias to all for your input.

Your welcome!

Thanks for the link Gdetrailer! Muchos gracias to all for your input.

Gdetrailer wrote:

The OP could get away with a smaller Tripplite, even the 1000W should be able to start the fridge.

Thanks for the correction on that. Good to know.

BuffaloIndian wrote:
I have decided replace my failed Dometic RM2652 RV fridge with a residential unit. I have found and ordered a replacement (Summit F882W) that fits my space (after removing an upper shelf); have removed the old unit, capped off the gas supply, and cleaned up the space. Now I am just awaiting delivery. My rig is a 2007 Sunset Creek with two slides.

Since this is a unit that we set up and leave in one spot for two or three months at a time, and never dry-camp, having an inverter/battery set-up is not essential. I am usually at my destination within 4 hours or 5 max. However, it would be nice to have the unit cooling while we travel and have the luxury of making stop-overs at the rest area.

I am looking at a Tripp-Lite MRV2012UL PowerVerter to replace my stock converter (2000 watts continuous inverter power), but I am not sure how exactly to wire it. Also, how many batteries do I need? Do I have to go with a 6-volt bank, or can I function with two 12-volt batteries?

Has any of you modified a travel trailer for this kind of set-up? Thanks

BuffaloIndian,

I have done this very modification..

I have a document which has a few pictures of our setup that may be of interest to you..

HERE

For what ever reason Google forces you to use their online PDF viewer which is fine for text but for pictures makes a mess of them.. To see the pictures better you can download the PDF and open using Adobe Reader..

I also can not guarantee how long the above link will work, for some reason Google logs me out once and a while and when that happens the link quits :M until I log in again :h

GordonThree wrote:
I installed an inverter, but still have my ammonia absorption fridge.

I too had considered the Tripp Lite... I know the brand well from the information technology industry.

A few things I didn't like about the tripp lite was lack of rv specific features; especially low battery voltage cut out. it will suck your batteries all the way to 0 if you let it. more expensive inverters like xantrex and magnum have protection against that sort of thing.

the charger is also a bit weak in the tripp lite. if you're getting a 2000 watt+ inverter, you need 600+ amp-hours of battery bank, and with that much battery, you want a 100+ amp charger... like the Magnum's 125A 4-stage charger.

as to how to wire it, instructions are provided in the installation manual. I can help with specific questions if you like.

many folks recommend just wiring the inverter to the batteries, and plugging your rv's power cord into the inverter. I went a step further and utilized the transfer switch built into my magnum. the power cord for the rv (shore power) connects to the magnum's input, and then the magnum is connected to the breaker panel where the rv power cord was connected before.

I like 12v batteries myself, big group 31 agm to be specific. lots of folks prefer 6v golf-cart batteries. it all depends how much space you have, how many batteries can you fit in there? if I had all the space of a huge motor home, I'd go with 2 volt "jars" instead of 6 or 12v batteries... the jars are designed for massive current and very long life, compared to 6 or 12v batteries.

6 or 12, you'll want at least 4 batteries to have enough amps to satisfy that inverter... do you have that much room?

:h

Really?

Honestly, I don't know where folks come up with these ideas AND POSTING such drivel WITHOUT truely taking a few minutes to FULLY research..

Tripplite like ALL other inverters DOES have 12V LOW VOLTAGE shutdown protection..

From the FIRST PAGE of the Tripplite manual for my PV1250..

And I quote..

HERE

Congratulations! You’ve purchased the most advanced, feature-rich
Inverter designed as a mobile energy source for your vehicle.
PowerVerter Inverters efficiently convert DC (battery) power into
120V AC (household) power, allowing you to use equipment you
commonly use at home—appliances, entertainment systems, computers,
power tools and more—while cruising the open road.
PowerVerter Inverters, through a high-efficiency conversion
process and a charge conservation setting, draw the highest
level of performance from your batteries without overtaxing them, lengthening their service life. An automatic low battery shutdown feature ensures you'll always have plenty of power for starting purposes.

You can also keep those group 31 AGMs, nothing than a very expensive yuppy toy.. especially with what the OP is needing which is for only 4-5 hr DRIVE.. Heck even a simple group 27 RV/marine battery will suffice for what they are wanting to do..

Why FORCE folks to spending top dollar on something (a expensive AGM)that is not needed.

The OP CAN EASILY go 12-24 hrs without an inverter provided they simply do not open the fridge more than a couple of times and they could simply get away with a frozen gallon jug of water in the fridge along with precooled food..

For what it is worth..

I USE a Tripplite PV1250 to run my home fridge conversion while traveling and overnighting.. And I do it ALL on ONE PAIR of Sams 6V GC batts (non AGM)..

We typically spend 10 hrs driving for two days and one overnight stop without power.. The charge line helps to offset the power used by the inverter/fridge. I set my inverter to use the load sense feature which turns the inverter on/off with the fridge compressor demand. I set the inverter to turn on with a 9W load so when I open the fridge door the light inside will trip the inverter on and the light will light up.

The OP could get away with a smaller Tripplite, even the 1000W should be able to start the fridge. Just make sure though you place the inverter CLOSE as possible to the batteris and use LARGE ga wire. I used 1/0 and only have 6ft total wire used (three foot each for pos and neg).

FUSE that wire NEAR the batteries, I used a 200A ANL fuse that is about 18" from the batteries..

The setup is priceless! :D

I have a tripplite and it will definitely shut down when voltage is Too LOW
In fact low voltage will cause it to trip Off with the compressor surge when the fridge cycles

smkettner wrote:
I would step down to the TL RV1012ULHW with just two batteries. Logistics of wiring are easier too and every post I read says 1000 watts is plenty.

I thought 1500W was recommended?

I would step down to the TL RV1012ULHW with just two batteries. Logistics of wiring are easier too and every post I read says 1000 watts is plenty.

http://www.tripplite.com/sku/RV1012ULHW

Box is fine for a couple group 27 and should operate fine on the five hour+ drive.

I always recommend 100 watts roof solar to keep the batteries maintained when off grid. This is mostly for storage and would not be enough to run the fridge alone. Would still provide a good supplement to the vehicle charge while in transit.