Losing time with Magnum 4448

Dapdan
Dapdan Solar Expert Posts: 330 ✭✭
in Off Grid Solar & Battery Systems #1
Hello all,

I have a magnum installed at my residence and another at a client and they both loose about 1 min per day. Has anyone else experience this and is there some thing else that can be done about it. It is not the digital clock because I had a different PSW installed at both locations and the clock keep perfect time previously. One was an Apollo 4048 and the other was an Schneider SW4048.

Cheers...
Damani
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  • BB.
    BB. Super Moderators, Administrators Posts: 33,613 admin
    #2
    Re: Losing time with Magnum 4448

    1 minute per day / (60 min per hour * 24 hours per day) = 0.0007 = 0.07% error

    That is probably is to be expected accuracy of 60 Hz for the inverter.

    If that, for example was an old Xantrex SW inverter, the spec. was +/- 0.04% (crystal regulated)

    For an MA4448PAW, the specification is 60 Hz ± 0.1 Hz. Or:

    0.1 Hz/ 60 Hz = 0.00167 = 0.2 %

    So--Well within the specifications for the inverter.

    Usually, better off with a simple clock that uses its own crystal. Or get one of the "atomic clocks" that sync with:

    https://en.wikipedia.org/wiki/Time_signal

    You are just not going to get the long term accuracy that you would from 60 Hz line frequency (line frequency can drift during the day as utility load vary, but the utility usually tries to bring it back to "zero" at the end of the day).

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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  • waynefromnscanada
    waynefromnscanada Solar Expert Posts: 3,009 ✭✭✭✭
    #3
    Re: Losing time with Magnum 4448

    I agree with BB. To take that further, I never expect an affordable consumer inverter to provide the accuracy required to keep perfect time on an electric clock. Knowing it's not going to happen, I don't use such clocks. If I were ever to get an inverter that had such accuracy, I'd consider it a total fluke, an accident.
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  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    #4
    Re: Losing time with Magnum 4448

    Utility power often isn't that accurate either. Usually they keep track of the frequency shifts and adjust so that it averages out.

    But not all the companies bother.
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  • Dapdan
    Dapdan Solar Expert Posts: 330 ✭✭
    #5
    Re: Losing time with Magnum 4448

    In other words...take what you get with high quality consumer grade inverters with respect to time drift on hz dependent clocks. I have found that with all of the inverters that I have used including the cheaper go power and xantrex rv type inverters digital clocks kept the right time. The magnum seems to be the exception as oppose to the norm for PSW. My limited experience with different PSW inverters seem not to be pointing towards "luck" or "accident" when it comes to keeping the right time and I can't change the crystal in my microwave or stove. I have been living with it but I asked the question because my client did and I could not give her an answer.

    Cheer...
    Damani
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  • Vic
    Vic Solar Expert Posts: 3,208 ✭✭✭✭
    #6
    Re: Losing time with Magnum 4448

    None of the off-grid inverters keep reasonably accurate time, it is NOT their primary job.

    AND, keep in mind that the good quality Inverter/Chargers will need to sync their AC waveforms to Gensets, on occasion. This means that that could introduce some additional errors, especially if the genset is used frequently.

    We use a number of battery-operated Quartz clocks, and "Atomic" (WWVB-synced) clocks most places. FWIW, Opinions, Vic
    Off Grid - Two systems -- 4 SW+ 5548 Inverters, Surrette 4KS25 1280 AH X2@48V, 11.1 KW STC PV, 4X MidNite Classic 150 w/ WBjrs, Beta KID on S-530s, MX-60s, MN Bkrs/Boxes.  25 KVA Polyphase Kubota diesel,  Honda Eu6500isa,  Eu3000is-es, Eu2000,  Eu1000 gensets.  Thanks Wind-Sun for this great Forum.
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