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Thread: New guy needs some help
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06-04-2013, 01:11 PM #1
New guy needs some help
Hi all
Im not a refrigeration engineer by any means but really need some advice! I am trying to run a freezer from a battery and inverter set up, but not having any joy gettting it to run.
Here is the freezer specs
Voltage 230v
50Hz
1.3A
LRA 9.5 - 9.7
Battery
60Ahr
Inverter
800w modified sine wave
It will almost start up but not kick over, i think this is due to the large inductive start up current but not sure what inverter i need or what to do to over come it.
Please any help would be amazing!!
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06-04-2013, 04:40 PM #2
Re: New guy needs some help
Look for start capacitor that will fit the compressor, it will require a special relay which will disconnect it and kick in the running capacitor.
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06-04-2013, 08:24 PM #3
Re: New guy needs some help
thanks for the reply is the start capacitor on the freezer? Do you know what relay i would need?
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06-04-2013, 09:22 PM #4
Re: New guy needs some help
It's not that simple unfortunately.
You need to know what make and model the compressor is.
dependent on the type of compressor you might or might not
be able to use a different starter to start the thing.
Your 800 watt inverter will only deliver about 3.5 amps, your
comp will pull 9 amp for a fraction of a second to a second. So
you either need a bigger inverter or you need to drop the
start current to 3 amp.
Post the details of the comp and maybe we can advise on
if it will start with a capacitor or not?
Regards
Rob
.Last edited by Rob White; 06-04-2013 at 09:27 PM.
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07-04-2013, 12:23 AM #5
Re: New guy needs some help
Yes, your inverter is too small for the job + the battery won't last long enough to do any reasonable amount of work.
To the optimist, the glass is half full. To the pessimist, the glass is half empty.
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07-04-2013, 08:14 AM #6
Re: New guy needs some help
thanks for the help so far, the compressor is Embracco EMI 70UER. The battery is quite small but needs to be run on a bike as i have a portable ice cream bike so weight is a factor! What inverter would you reccomend if i was just to uprate the inverter?
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07-04-2013, 07:39 PM #7
Re: New guy needs some help
Additional dynamo(s)?
The problem you face is the huge starting current you are facing with any compressor.
As Rob stated above, it will be at least 9 Amp and maybe even more for a fraction of a second when the compressor just start to turn over.
To be on the safe side you would look at an inverter capable of supplying in the region of 15-20 Amp.
Another thing you need to be aware of is the battery's capacity. 230V x 1.3 A = 299W. 299W / 12V = 25A. Therefore a 100 AmpHrs leisure battery is likely to only last a couple of hours...
Tried to use dry ice or liquid nitrogen?