One more Kill-A-Watt question

PhilS
PhilS Solar Expert Posts: 370 ✭✭✭
in Advanced Solar Electric Technical Forum #1
Mine came today and I could use trial and error but prefer to ask here so I can start out measuring correctly.

Will it work properly and give valid measurements if the inverter is in "search" mode? Or will it just be resetting itself everytime "search" starts? This question just refers to loads on my "lights and entertainment" inverter and circuit, as it's in search most of the time.

My new fridge was delivered Sat and it works great!! The Magnum was going into search mode but I noticed that when the inverter came out of search, the fridge would start what I think was a defrost cycle.... read 30ADC on the Magnum remote. For instance, turn on range light, it "ramps up", meaning the inverter was in search. Turn off range light and inverter should go back into search. It doesn't and there's that 30A draw. Gotta be a heater in the fridge as normally it's drawing 15A according to my Fluke (reads "zero amps DC" on the remote). Some time later (a couple of hours maybe?) the inverter will go back into search when the fridge cycles off. Bring it out of search and the same cycle starts again.

I tried it a few different times with the same result. So I turned off the "search" mode, thinking that "no power" is resulting in a reset of the fridge programming and starting the defrost cycle. Since the Magnum claims only 3 watts with no load it's not a big deal anyway. And since turning off search, the fridge has been sounding and operating normally (as well as I can tell having used propane refrigerators for the last 30 years).

Does anyone here agree on what is happening between the fridge and "search"? Or have another idea?

Phil
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  • mike95490
    mike95490 Solar Expert Posts: 9,583 ✭✭✭✭✭
    #2
    Re: One more Kill-A-Watt question

    What's the voltage of your system (30A x ??V = Watts)

    How many watts does fridge normally draw ? (120VAC)
    Powerfab top of pole PV mount | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
    || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
    || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

    solar: http://tinyurl.com/LMR-Solar
    gen: http://tinyurl.com/LMR-Lister ,

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  • PhilS
    PhilS Solar Expert Posts: 370 ✭✭✭
    #3
    Re: One more Kill-A-Watt question

    Hi Mike,

    12V system. I checked the 30A Magnum reading against my Fluke and IIRC the Fluke said 35A (it wasn't a huge difference). Most of the time the fridge is running, it's drawing the 15ADC tho, so the increased draw I'm thinking must be for a defrost cycle?

    Oh, and I should mention that when it's drawing that 30A, the fridge doesn't appear to be doing anything (no noises at all).

    Phil
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  • PhilS
    PhilS Solar Expert Posts: 370 ✭✭✭
    #4
    Re: One more Kill-A-Watt question
    mike90045 wrote: »
    How many watts does fridge normally draw ? (120VAC)

    THAT I'll tell you later in the week after I've tested it with the Kill-a-watt.

    Phil
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  • System2
    System2 Posts: 6,290 admin
    #5
    Re: One more Kill-A-Watt question

    Interesting. Both my 10 cu ft chest freezer and my modified chest fridge, each draw about 9 amps on the 12 volt DC side of the inverter. 15 amps sounds pretty heavy, not to mention the 30 amps. Guess I'm lucky.
    Wayne
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  • mike95490
    mike95490 Solar Expert Posts: 9,583 ✭✭✭✭✭
    #6
    Re: One more Kill-A-Watt question
    PhilS wrote: »
    Hi Mike,

    12V system. I checked the 30A Magnum reading against my Fluke and IIRC the Fluke said 35A (it wasn't a huge difference). Most of the time the fridge is running, it's drawing the 15ADC tho, so the increased draw I'm thinking must be for a defrost cycle?

    Oh, and I should mention that when it's drawing that 30A, the fridge doesn't appear to be doing anything (no noises at all).

    Phil

    30A @ 12.5V = 375 Watts [silent, defrosting ?]
    15A @ 12.5V = 187 watts [normal run cycle ?]
    Powerfab top of pole PV mount | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
    || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
    || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

    solar: http://tinyurl.com/LMR-Solar
    gen: http://tinyurl.com/LMR-Lister ,

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  • PhilS
    PhilS Solar Expert Posts: 370 ✭✭✭
    #7
    Re: One more Kill-A-Watt question

    Hooked up my new Kill-a-watt to the fridge last night. As soon as I transferred the plug to the meter, the fridge immediately showed a 300w load but made no noise. After about 5 minutes the load dropped to 140w as the compressor kicked in. The load gradually dropped to about 100w until the compressor shut off (another 5 minutes?). So.... this fridge MUST be on an inverter that doesn't 'search' or it'll immediately begin a defrost cycle everytime the inverter comes out of search.

    In the first 12 hours with the Kill-a-watt, KWhr was .46 which so far is within my goal of less than 1 KWhr per day. MOST of the time the fridge reads 00w which means it's drawing little power until it starts a cycle, which normally doesn't include the 300w heat load. I'm not sure if I'll be able to tell how often the heat cycle happens other than chance glances at the meter. On the other hand, it doesn't matter much as long as the total consumption is acceptable.

    After a few days on the refrigerator I'll start moving the Kill-a-watt to other loads.

    Phil
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