Running fridge/freezer on inverter

[AC/DCdude17]

We got our share of snow in my area and many people had an outage
lasting quite a while. I'd like to be able to power a freezer on
inverter powered from car battery for extended outages. My freezer takes
115W, 145VA to sustain operation, but the compressor is rated at
7.5LRA(locked rotor amps, which you can use to estimate your
fridge/freezer's peak power requirement) and I guess that comes to 900
peak watt.


The 140W inverter I mainly use for charging digital camera
batteries in my car definitely won't start this freezer, but my
700W(1000W peak) inverter can start it(barely.. it beeps when the freezer
starts). Is there anyway I can run a freezer/refrigerator on an inverter
short of getting an inverter with a peak wattage that can accomodate 120V
* compressor's LRA? It's really foolish having to dedicate a 700W(1000W
peak) inverter for a 115W freezer.


Searching the internet showed there's an "easy start kit" that lower's
peak current by starting compressor slowly, but I haven't been able to
find any.

I suppose I could use a series reactor to restrict the starting current
but could the comrpessor start up with restricted starting current?

 

[Chris Hill]

We got our share of snow in my area and many people had an outage
lasting quite a while. I'd like to be able to power a freezer on
inverter powered from car battery for extended outages. My freezer takes
115W, 145VA to sustain operation, but the compressor is rated at
7.5LRA(locked rotor amps, which you can use to estimate your
fridge/freezer's peak power requirement) and I guess that comes to 900
peak watt.


The 140W inverter I mainly use for charging digital camera
batteries in my car definitely won't start this freezer, but my
700W(1000W peak) inverter can start it(barely.. it beeps when the freezer
starts). Is there anyway I can run a freezer/refrigerator on an inverter
short of getting an inverter with a peak wattage that can accomodate 120V
* compressor's LRA? It's really foolish having to dedicate a 700W(1000W
peak) inverter for a 115W freezer.


Searching the internet showed there's an "easy start kit" that lower's
peak current by starting compressor slowly, but I haven't been able to
find any.

You aren't losing much by using the inverter that is properly sized
for the job. Remember too that the wiring to the inverter must be
properly sized for the job, I suspect that is what your problem really
is.>

 

[SQLit]

We got our share of snow in my area and many people had an outage
lasting quite a while. I'd like to be able to power a freezer on
inverter powered from car battery for extended outages. My freezer takes
115W, 145VA to sustain operation, but the compressor is rated at
7.5LRA(locked rotor amps, which you can use to estimate your
fridge/freezer's peak power requirement) and I guess that comes to 900
peak watt.


The 140W inverter I mainly use for charging digital camera
batteries in my car definitely won't start this freezer, but my
700W(1000W peak) inverter can start it(barely.. it beeps when the freezer
starts). Is there anyway I can run a freezer/refrigerator on an inverter
short of getting an inverter with a peak wattage that can accomodate 120V
* compressor's LRA? It's really foolish having to dedicate a 700W(1000W
peak) inverter for a 115W freezer.

You can buy lots of extra stuff and try to lower the amps or watt
requirement for starting. I will bet that when you discover the cost of the
soft start equipment it would have been cheaper buy a 1000w inverter. They
are not that expensive. Besides it will give you something else to run when
the freezer is not. I personally would not be to worried about a freezer
when the temps are low. I had a power outage in Arizona ambient was about
100 F. I did not open it up until the power came back, 2 days. I kept a min
max thermometer in it and it never rose high enough to be in danger.

 

[ptaylor]

You aren't losing much by using the inverter that is properly sized
for the job. Remember too that the wiring to the inverter must be
properly sized for the job, I suspect that is what your problem really
is.>

Hmm,I'm slightly suspicious of the wire size too,it sounds like it might
be too small.
I tried to run my PC from my 300W inverter,and it would start
booting,then mysteriously turn off after 2-3 seconds.
After using larger 10AWG wire,and a much shorter run (8-10
inches,instead of 2-3 feet!) I can now run the PC *and* monitor just
fine! I strapped the inverter to the side of a 12V 17Ah SLA battery I
got for $10 surplus,so it's one nice unit,and I could keep the wires
short.I also made a set of "jumper cables" for it from some heavy wire
and alligator clips,for recharging,tying into the other
batteries,jupstarting the car,etc.Kinda like a homebrew version of one
of those Coleman/Prestone jumpstart power pack things,with a 300W
inverter to boot.It works great!!

 

[Dimitris Tzortzakakis]

20 hours on 3.4 gallons!!!Even a tank at full speed doesn't consume so
much.Better buy nothing, save the money because power outages happen every
now and then.Do you have a lot of goodies in the freezer?

 

[Spehro Pefhany]

20 hours on 3.4 gallons!!!Even a tank at full speed doesn't consume so
much.

M1A1 60 gallons per hour cross-country (1200 gallons in 20 hours).
*Idling* it would use 200 gal. in 20 hours.

Better buy nothing, save the money because power outages happen every
now and then.Do you have a lot of goodies in the freezer?

3.4 gal of gas costs just a few dollars, what are you talking about?

Best regards,
Spehro Pefhany

 

[Spehro Pefhany]

Not in Greece it doesn't....(c;

Say EUR0.80/l * 3.8 (US gallons) * 3.4 ~= EUR10. I doubt you can get
a bottle of Ouzo for that. ;-)

Best regards,
Spehro Pefhany

 

[AC/DCdude17]

X-No-Archive: Yes

By the time you buy enough battery power to sustain the freezer for
even just 8 hours and the charger to recharge it and the maintenance
of having to replace the dead batteries every 3 years.....

Who said I need to sustain the freezer on normal cycle? I need to sustain the
tempreature low enough to prevent spoilage of food inside.

A freezer can often keep it below freezing for a whole day, but being able to
run the compressor every 12hrs or so for 30min is going to help quite a bit.
We seldom have power outages lasting more than a few min. It will not be
powered from a dedicated battery bank. The inverter will simply get hooked up
to my car and fridge will run with the engine running.

This freezer only takes 115W nominal, so input to inverter is about 140W or
12V 12A.

If I run it on a fully charged car battery for 30min, it will use up 6Ah from
the battery and that amount houldn't interfere with the ability to start the
vehicle.

Once I do this, I can just do this again after I used the car so the battery
is brought back to full charge.

you're much
better off buying a nice genset that can power lots more stuff and has
nearly zero maintenance just sitting there....

This isn't correct about a gasoline powered generator. Ever had trouble
starting a lawn mower that was stored until the next season by simply putting
it away normally?

Gasoline don't keep very well and it's known to gum up the fuel system.

I recommend tossing caution to the wind and buying the Honda EU3000is
super quiet, electric start at around $1800 on the net. It's a honey!
http://www.hayesequipment.com/eu3000is.htm

It won't even come off economy speed crankin' that freezer.....
With a 750W load, it will run 20 hours on 3.4 gallons of gas! Mine
does, easy.

Oh please. There is no way I'm going to justify spending nearly two grands
for rare power outages.

 

[Dick]

X-No-Archive: Yes

Larry W4CSC wrote:




Who said I need to sustain the freezer on normal cycle? I need to sustain the
tempreature low enough to prevent spoilage of food inside.

A freezer can often keep it below freezing for a whole day, but being able to
run the compressor every 12hrs or so for 30min is going to help quite a bit.
We seldom have power outages lasting more than a few min. It will not be
powered from a dedicated battery bank. The inverter will simply get hooked up
to my car and fridge will run with the engine running.

This freezer only takes 115W nominal, so input to inverter is about 140W or
12V 12A.

If I run it on a fully charged car battery for 30min, it will use up 6Ah from
the battery and that amount houldn't interfere with the ability to start the
vehicle.

Once I do this, I can just do this again after I used the car so the battery
is brought back to full charge.

Many RV owners run apartment size refrigerators on inverters. The duty
cycle of a refrigerator is low enough that they can get by with just a
few batteries. However, they use deep discharge batteries, often 4
golf cart types. Deeply discharging car batteries drastically reduces
their life.

Oh please. There is no way I'm going to justify spending nearly two grands
for rare power outages.

You don't need that size for a freezer. Honda makes a nice 1KW unit
that sells for about $700. It is a DC generator that drives an inverter.

For your use a Coleman 1.8KW unit for $500 would be adequate.

 

[East-of-lake]

Just a thought that I've had before:

If your power outage is due to SNOW and you're trying to keep things cold
why don't you put it in a box outside in the snow? Here in the northwest
we've had a few outages that lasted over a day with temperatures in the
teens and twenties. I just put the frozen stuff in a box outside.
Refrigerated stuff had to be cycled into the garage which was cold but not
freezing.

 

[Q]

How would Bush's oil company cronies make any money at 50 cents per gal? The
last thing Bush wants is cheap gasoline.

Q

 

[Ray Drouillard]

If you have a bunch of snow, why are you worried about your freezer?
Just put all your frozen stuff out on the porch.


Ray