DC compressor fridge power usage question
Hey guys - Looking for some help on a fridge topic. First post and have been reading as much as possible on this forum as well as others on the topic... has been very helpful. Quick summary of my ...
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Almot wrote:+Denny & Jami wrote:
One thing to remember when looking for a fridge with a 12v compressor is the compressor is still 120v AC it just has a dedicated inverter.
Nope. Danfoss is a DC compressor. This is the beauty of it - there is no high peak of start-up current and no inverter losses.
When 12V DC fridge comes with AC option, it has a converter that takes 120V AC and makes DC to run a compressor. Though I think that paying extra for AC option doesn't make sense because a camper or trailer usually has a converter already.
Not exactly correct. The compressor is not a 12V compressor in the true sense of the word. The electronic module takes a 12V input and converts it to a low level, split phase voltage. Because of this phase split, you can not measure it with standard test equipment. Some of the fridges, like Vitrifrigo, also accept 120V at the electronic module, but it steps it down and converts it to that same split phase voltage.
The Danfoss compressor will draw around 10V peak at startup, but that lasts less than a second, then it will draw approx 5A running. Total power consumption is dependent on the duty cycle which is largely affected by he insulation around the box. A 50% duty cycle would be perfectly acceptable, less would be a bonus.
