[wtd] Backup Power

Discussion in 'Wanted' started by a-jap, 19 Mar 2013.

  1. a-jap

    a-jap

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    Hi

    I need a pure sine inverter 800w or higher and deep cycle batteries.

    Second 8 hour outage for the month, looks like its going to get worse.

    Thanks
     
    Last edited: 19 Mar 2013
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  3. jclaas

    jclaas

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    Hi

    I am interested in an inexpensive automatic backup power system.

    (Inverter type seems cheapest)
    What is your opinion on the modified sine wave inverters for pumps and heaters?
    *pure sine wave seems expensive.

    Equipment to run:
    200w heater
    32w return pump
    9w skimmer
    15w & 5w undergravel pumps
    3 w wavemaker


    Calculations learned from the following website:
    http://www.sinetech.co.za/invselect.htm
    Total power: 200+32+9+15+5+3 = 264w.
    Continues power: 264w + 20% = 316.8w.
    Peak power: Total power (264w) x 3 = 792 w (peak power.)

    BUT AFTER SOME PRICING THE ABOVE EQUIPMENT TO RUN ADDS TOO MUCH COST.

    What should i run?

    Please be kind to advize me advize me on an adequit inverter & battery combination.
     
    Last edited: 26 Jul 2013
  4. lIghty

    lIghty

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    Modified Sine is fine for resistive load, such as heaters and incandescent light, but not good for inductive loads such as pumps etc.

    The peak power "factor" only comes into pay for inductive load, Of those you have listed the all but the heater is inductive, but there wattage is not high. 32+9+15+5+3 = 64W time that by a factor of 3 (would be fine) only equates to a peak of 192W, not add the resistive load of 200W (heater) you only total peak of about 392W.

    in saying that, if you had to calculate the continues power with 20% margin, it would work out to 317W. A DECENT 300W inverter should run this (as true draw should be around 264W) and they generally have a surge / peak rating of 1.5-2 times the rated power, BUT YOU NEED TO CHECK THE DATASHEET FOR THE INVERTER IN QUESTION!

    Looking on the sinetech web site the SK350-212 should do the job fine!
     
    Last edited: 26 Jul 2013
  5. mariusmeyer

    mariusmeyer

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    Only problem with the SK series is that they don't have a built in auto transfer switch. A person will have to manually switch he inverter on when the power fails. he ST series comes with transfer switch.
     
  6. Quintin

    Quintin

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  7. Aquetas

    Aquetas

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    @Quintin is AliExpress not the old Alibaba site?

    Have you had any issues with buying from the guys on there? I know its like Ebay but heard a lot of guys complaining about sellers on that site.
     
    Last edited by a moderator: 26 Nov 2015
  8. Quintin

    Quintin

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    No idea.
    I started using them myself when we moved to SA from the UK about 3 years ago.
    Here is my thread with links to all the stuff I purchased from them...
    New Tank Build plus electronics - Marine Aquariums South Africa

    Just remember that like anything you buy cheap and nasty will always be cheap and nasty so rather spend a bit of extra cash upfront and get something decent that going for the $10 specials....

    I have no issues with any of the stuff I purchased from these guys.

    Where do you think the guys selling on Ebay get their stuff from?
     
    Last edited by a moderator: 26 Nov 2015
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