Inverter/small refrigerator

filrupmark wrote:
We purchased a 4.3cuft. Whirlpool refrigerator for additional refrigerator space. I want to install an inverter for traveling. Our rig currently has dual AGM batteries . The tag on the frig states .8 amp draw ? Really ! Seems lower than I thought it would be. Anyway I was thinking about a 1000 watt inverter with a double pole double throw switch for switching from inverter to shore power while hooked up. Only one circuit from my breaker panel will be hooked to the inverter. Any thoughts would be appreciated.

1000 watts should be fine. I recommend sine wave only.

A small automatic transfer switch is just $50
http://www.donrowe.com/KISAE-TS15A-Automatic-Transfer-Switch-p/ts15a.htm

Thanks, guys! Glad to know that what I read about dimmers was wrong BEFORE I tried it! The thermostat looks good -- although I know from experience I will get a LOT of frost buildup if I run a wire through the door.

Naio wrote:
Thanks Roy Ken and GdeTrailer for the two options and the very clear illustrations! I know those took time and effort, especially Roy Ken's.

A simple way to get more insulation efficiency: Use a freezer instead of a fridge. Turn it down all the way, and if it still freezes I hear a dimmer switch works.

Using a chest freezer as a fridge can be done but the T stat typically will not have enough range to get it warm enough so the food doesn't freeze..

Off grid folks have successfully modded chest freezers in to a fridge by bypassing the built in T stat and using a PID type adjustable T stat.. Allows precise temperature control and take advantage of a chest freezers efficiency..

Dimming controls are not compatible with heavy induction loads and will either burn up the dimmer or compressor in the process.

On edit..

Found some instructions of converting a chest freezer FYI..

HERE

Naio wrote:
Thanks Roy Ken and GdeTrailer for the two options and the very clear illustrations! I know those took time and effort, especially Roy Ken's.

A simple way to get more insulation efficiency: Use a freezer instead of a fridge. Turn it down all the way, and if it still freezes I hear a dimmer switch works.

A dimmer switch would not work for a compressor-driven fridge or freezer. If the dimmer switch functions with an inductive load (many will not), it would very likely burn out the compressor motor in short order. If the fridge/freezer has digital electronic controls, those may cease to function first, possibly not fatally.

Freezers and fridges, like air conditioners and furnaces, are generally either on or off, and the duty cycle is controlled by the thermostat to maintain temperature.

Thanks Roy Ken and GdeTrailer for the two options and the very clear illustrations! I know those took time and effort, especially Roy Ken's.

A simple way to get more insulation efficiency: Use a freezer instead of a fridge. Turn it down all the way, and if it still freezes I hear a dimmer switch works.

RoyB wrote:
Blue sea sells this manual selector switch which would be perfect for your manual selection.


Google Image

You can add additional switches to this to control additional circuits as the needs grow...

Typical installation might look like this google image from a different company manual switch photo...


This would be a typical schematic for multiple banks of manual switches...


This would be the SAFTEST way to do this following all of the Wiring Install rules etc. This looks nice sitting beside the typical Power Distribution Chassis like shown here...


Google Image

I use a couple of pure sine wave Power Inverters along with my OFF-ROAD setup for operating things OFF-ROAD when needed. Nothing fancy like shown above for manual switching into the system. I just run a couple of HD Extension cords with a mulit-head power taps from the Power Inverter location to a couple of cabinet tops close to the appliances I want to run off of the Power Inverters. Then just simply plug them into the multihead power taps...

My poor man's manual transfer switch hehe...


My Power Inverters are installed as close to the larger battery bank to operate them as I could get ans still be inside my trailer. I am about 5-6 feet away from my main Battery DC switch setup. A 1000Watt PSW Power Inverter will require additional batteries to operate it for sure...

I get away with a 600WATT PSW Power Inverter for running the Home Entertainment items, a bunch of cell phone chargers, computer chargers, a couple of fans, lights etc when camping off the power grid... My small 3-mode fridge without a freezer compartment runs just fine from 120VAC-Propane-DC.

My game plan to run all we want to run during the day/night run off the batteries and then hookup the Popup trailer Shore Power cable to my 2KW Generator each morning when allowed to run generators and let the on-board PD-9260C Converter/charger unit re-charge my battery bank back up from its 50% charge state to its 90% charge state so we can do all of this all over again for the day/night run off the batteries. We can do a good 12-14 of these 50% to 90% three hour charge cycles without having to do a full 100% charge state which would take around 12 hours of generator run time to do. Been doing these routines since 2009 and just now having to replace my battery bank...

This is us camping off-grid at Doris Camp at Medicine Park, OK with no Shore Power. Note the two extension cords running over to the picnic table to run a few things especially the box fan to keep mosquitoes away from us hehe...


Roy Ken

Roy,

That is absurdly over the top ridiculous cost wise...

Why put so much burdens on a simple task?

OP simply needs a DPDT (Double Pole Double Throw) toggle switch WITH CENTER OFF POSITION..

Looks like this..



Handles 20A and costs maybe at the most $3 at Home Depot or Lowes..

Op would need to put in a electrical box but once again, those are cheap at perhaps $1.50 anywhere electrical supplies are sold..

Source power is connected to the outside terminals (hot and neutral), the fridge gets connected the the two center terminals (hot and neutral), making sure that the hots line up with all the hots and the neutrals line up with all the neutrals..

It isn't like they are going to power up a space craft and a simple regular toggle switch is plenty sufficient for the job..

To operate, the OP will flip from one power source to the center OFF..

Wait a couple of minutes (this allows compressor time to cool and the pressure to equalize before restarting).

The flip from the center OFF position to the other power source.

Easy peasy, low cost, readily available.

You can get a better compressor in a mini fridge but it cost you a extra $100 to save 0.14a at 120Vac over the next best. Most are rated to use almost as much as a 9 or 10 ft apartment fridge because they use the same cheap compressor in everything from a cube fridge on up.

1,000 watt inverter will be plenty. That is what I used on our chest freezer in our 5er while traveling all day for 3 weeks.

Thanks for all the ideas and thoughts.

Blue sea sells this manual selector switch which would be perfect for your manual selection.


Google Image

You can add additional switches to this to control additional circuits as the needs grow...

Typical installation might look like this google image from a different company manual switch photo...


This would be a typical schematic for multiple banks of manual switches...


This would be the SAFTEST way to do this following all of the Wiring Install rules etc. This looks nice sitting beside the typical Power Distribution Chassis like shown here...


Google Image

I use a couple of pure sine wave Power Inverters along with my OFF-ROAD setup for operating things OFF-ROAD when needed. Nothing fancy like shown above for manual switching into the system. I just run a couple of HD Extension cords with a mulit-head power taps from the Power Inverter location to a couple of cabinet tops close to the appliances I want to run off of the Power Inverters. Then just simply plug them into the multihead power taps...

My poor man's manual transfer switch hehe...


My Power Inverters are installed as close to the larger battery bank to operate them as I could get ans still be inside my trailer. I am about 5-6 feet away from my main Battery DC switch setup. A 1000Watt PSW Power Inverter will require additional batteries to operate it for sure...

I get away with a 600WATT PSW Power Inverter for running the Home Entertainment items, a bunch of cell phone chargers, computer chargers, a couple of fans, lights etc when camping off the power grid... My small 3-mode fridge without a freezer compartment runs just fine from 120VAC-Propane-DC.

My game plan to run all we want to run during the day/night run off the batteries and then hookup the Popup trailer Shore Power cable to my 2KW Generator each morning when allowed to run generators and let the on-board PD-9260C Converter/charger unit re-charge my battery bank back up from its 50% charge state to its 90% charge state so we can do all of this all over again for the day/night run off the batteries. We can do a good 12-14 of these 50% to 90% three hour charge cycles without having to do a full 100% charge state which would take around 12 hours of generator run time to do. Been doing these routines since 2009 and just now having to replace my battery bank...

This is us camping off-grid at Doris Camp at Medicine Park, OK with no Shore Power. Note the two extension cords running over to the picnic table to run a few things especially the box fan to keep mosquitoes away from us hehe...


Roy Ken