red31 wrote:
What is the minimum voltage @ the fridge required to maintain temp with ambient temps being 100F, 80F, 60F, 40f and say 50 mph?
The specs I often see are 10-11A for the firdge DC heater, can you provide info on currents higher than that or wattages?
Let us agree that not all PUs or vehicle are the same.
I'm happy to agree! Anyway, the DC Fridge heaters are simple resistance coils (sort of like old-style toasters). The resistance in a Norcold N300.3 is "12VDC" heater is 1 Ohm. Larger refrigerators have lower resistance, allowing higher current. When supplied with 12V, the N300.3 will generate 12V * 12A = 144W. When supplied with 14V, it will generate 14*14 = 196W. But voltage drops occur at high current, causing less Voltage to be seen the Fridge heater coil than you supply from the Batteries or Bargeman.
In hot temperatures, you need to have the heater spend a higher proportion of time "ON", and a lower proportion "OFF". The ability for an "absorption" fridge to maintain low temps depends on insulation and ambient temperature - above 90F, they need to be "ON" almost continuously. YMMV, of course. I used to own a Norcold N300.3, I replaced it with a compressor Fridge a few years ago, because the Norcold couldn't do a good job in Nevada summers (that's where I live).
