Need help setting up solar electric system on our converted bus/motor home

TellGRBill

DROK 200123 Digital Multimeter AC 80-260V 100A Voltage Amperage Power Energy Meter AC Volt Amp Tester Voltmeter Ammeter Watt Meter

With the CT around the 120 volt power wire coming off the inverter

Looking at this image I think I can see Wh in the energy corner.

The meter, and numbers are so small that I probably missed the h

BB.

Yes, that is Watt*Hour = Energy in the corner (Wh).

Guessing that the Voltage, Current, and Power are "instantaneous" readings (updated once a second or whatever).

The Energy is cumulative between resets. If you had a refrigerator running as:

120 Watts average
50% duty cycle (motor on 50% of the time)
And 24 hour period

120 Watts * 0.50 duty cycle * 24 hours = 1,440 Watt*Hours (Wh) per day (average)

Note that a typical frost free Energy Star refrigerator may have door heaters (to keep the door/gaskets from sweating in humid weather). And there is an approximately 300-600 Watt Calrod heater inside below the evaporator to defrost it once or twice a day (yes, I had a freezer apart as it got iced up and the defrost heater tripped and there is a dimly glowing red heating element inside the freezer to de-ice the evaporator). So you can see a few minutes (or longer) of 300-600 Watts on your meter as the fridge defrosts.

Don't disconnect the defrost heater... We had a member here that did the test. Yes, saved energy in the first 24 hours, but after that, the increasing frost/ice on the evaporator blocked airflow and ended up consuming more energy (compressor motor running more) to make up for the decrease in air circulation.

-Bill

706jim

Agree: Keep the defroster. (Former propane fridge owner)....

TellGRBill

Thanks Bill,

Our refrigerator was built to be a freezer but I put a universal refrigerator thermostat on it.  It has a back wall and behind it are the evaporator coils and a fan blowing across the coils.  There must not be a defroster because, if we don't turn it off regularly, the coils and back wall build up frost.  The bus/motor home at our farm is used like a cottage so we can turn off the thermostat at night, and on again in the morning.  Thus we save electricity use`with the door closed, compressor not running, and the freezer quality insulation.  The box and contents stay cold, and the frost doesn't build up. The water from turn off defrosting goes down a tube into the ground under the bus.

Ralph Day

I always used to shut down the freezer to defrost, not anymore.  Get a good (or cheapo) ice scraper like you'd use on your car or truck (depending in your location) and use that.  A little muscle and you can defrost in 5 minutes. 
Pull out everything, put into boxes or laundry baskets, chip off ( but don't hammer it off or damage the inside liner) the frost, scoop it out with a dustpan and fill it up again.  Done if 5 minutes.

TellGRBill

That is a dangerous practice.  My brother-in-law rushed his defrost by chipping the ice and had to buy a new refrigerator because he poked a hole in the evaporator freezer liner.  If you add to your advice:" let the frost soften before scraping"  you would have good advice for defrosting.  Hot water or hair dryer speeds it up too.

Our upright freezer has the evaporator behind a wall and a circulating fan blowing the air across it into the food compartment.so we have to just let it melt.