Chopping some power bills

Discussion in 'Electronics & Electrics' started by AgB deano, Nov 3, 2009.

  1. Piroteknik

    Piroteknik Member

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    I got a good power board, 4 port, each with individual toggle on/off and a All off button, $40 from memory, bought it a year ago at bunnings.
     
  2. mareke

    mareke Member

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    You've been lucky so far. I've been using the same board from Bunnings and have returned 2 of them. I returned one recently because while the light was on indicating there was power there was no power. I’m still waiting for one to be made that doesn’t break down within 12 months of buying it.
     
  3. LethalCorpse

    LethalCorpse Member

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    If he's had one running fine for twelve months and you've had several blow up, the problem is probably not the boards.
     
  4. mareke

    mareke Member

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    Maybe. One possible cause is that the voltage at wall sockets in my place averages 255 volts instead of 240 volts and climbs as high as 265 volts at night due to being in close proximity to a transformer. The high voltage may cause the mechanism by which the remote switches the power on and off to become damaged.
     
  5. LethalCorpse

    LethalCorpse Member

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    Or that you're just running things on it that it can't handle. Never mind what it's supposed to be able to handle, you're not going to get anywhere by continually taking the thing back for replacement. Work out what it can happily run, and run that on it.
     
  6. mareke

    mareke Member

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    That's not the cause of the failures I've had. The board is rated at 10 amps and 2400 watts and I use it to run a plasma TV that uses around 300 watts and I have no other devices attached to it. If it can't handle that it's a piece of shit.
     
  7. [SweN]

    [SweN] Member

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    i wouldnt think the extra voltage you speak of would be damaging the device tho :confused: 260V doesnt seem terribly excessive. you would expect the board would be able to handle an insulation test of around 500v?

    i have been very very wrong before tho :Paranoid:
     
  8. LethalCorpse

    LethalCorpse Member

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    Certain the power supply of that plasma is doing what it's supposed to? Tried running something else off it that pulls about 300W to see what it does?
     
  9. mareke

    mareke Member

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    It's the on/off mechanism controlled by the remote that is prone to breakdown and this has nothing to do with the appliance you are using. Each time I switch the TV on or off with the powerboard’s remote there is an audible click within the powerboard as the remote signal activates the on/off switch in the powerboard. Unlike a physical switch that you push with your finger the on/off switch activated by the remote signal is more delicate than a normal physical switch and is prone to failure particularly if you use it a lot. I switch the TV on and off using the powerboard remote to save on standby power so the on/off mechanism in the powerboard gets used a fair bit.
     
  10. LethalCorpse

    LethalCorpse Member

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    Of course it bloody does. The type of load affects arcing across the contacts every time you make or break the connection. A plasma TV is a fairly big inductive load, which could certainly cause significant arcing. The board has relays in it (which is what you're trying to describe when you say "on/off switch activated by the remote signal") which can be of varying quality. Their operation, as far as the supply and load are concerned, is exactly the same as a mechanical switch (the one you push with your finger). Like switches, relays come in a wide range of qualities and tolerances. If the relays in the particular board you're using can't handle the particular load you're connecting to them, that arcing will, over time, cause the relays to fail. This will happen with all relays eventually, but when it happens depends on the quality of the relay and the abuse you're subjecting them to. Stop your whingeing (both here, and at the bunnings return counter) and either use the product for something it can handle, or get them to refund/exchange for something beefier.

    EDIT: and if you can't accurately describe a relay, how the hell do you know what voltage your mains is at?
     
    Last edited: Nov 23, 2009
  11. mareke

    mareke Member

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    I don’t see it as unreasonable to expect a product to do what it is rated to do. The board is rated at 2400 watts and 10 amps and if it can't handle a 300 watt TV it shouldn't be rated at 2400 watts. If it can't handle an appliance which is a small fraction of its stated maximum rating I believe I have the right to take it back to the place of purchase. Bunnings would not give me a refund (which was my preference) and gave me the option of an identical replacement or a conventional powerboard and I already have more conventional powerboards than I need so I chose a replacement.

    I used a multimeter to measure the voltage at the power points at my place.
     
    Last edited: Nov 23, 2009
  12. OP
    OP
    AgB deano

    AgB deano Member

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    While I agree with your points, pretty much all newer tv's will not turn on when regaining mains, they will remain in standby until switched on. If this is the case then there will not be a significant arc on the contacts as the tv will pull around 5-15W in standby and will be switched "on" when the tv is turned on. I would definitely put it down to really shit quality relays which is quite disappointing as 12VDC/240VAC 10A relays (assuming these are being used) would cost a lot less than the IR module and are the most likely components to fail through general usage.
     
    Last edited: Nov 23, 2009
  13. MUTMAN

    MUTMAN Member

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    i assumed they used solid state relays...triacs at a guess :confused:
     
  14. OP
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    AgB deano

    AgB deano Member

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    I'd bet they don't. Mareke stated that he can hear a click, probably made by an electromechanical relay.

    I'd also bet that if these boards used solid state relays, there wouldn't be anywhere near as many failures.
     
    Last edited: Nov 23, 2009
  15. desertstalker

    desertstalker Member

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    Could it be the inrush current of the PSU in the TV, AFAIK they can be pretty high?
     
  16. OP
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    AgB deano

    AgB deano Member

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    Armatures are usually built for a higher current than the ampere rating and a PSU pulling over 10A in a split second is extremely unlikely unless you have a failure. His TV isn't stuffed, the board is.

    On top of that the board would have an overload fuse in place which would blow before that armature would fry.

    It would be more likely that the relay is stuffed after a period of use which is usually the biggest point of failure for any electromechanical relay and is exactly why a SSR would be nice to have (or a better quality EMR)

    EMR's always fail in the open position, hence the 240VAC circuit would not complete. The user would think the board is stuffed because it would not make the clicking noise and there would be no power to the sockets. Sound about right Mareke?
     
    Last edited: Nov 23, 2009
  17. mareke

    mareke Member

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    That sounds right. When the powerboard failed the light that goes on when there is power was on but there was no power from the socket. This was the case with all four sockets. Also the light would not turn on or off using the remote but then the next day the remote did switch the light next to each socket on and off but there was still no power presumably because the relay had failed in the manner you suggested i.e. in the open position. The board has an overload switch by the way. If solid state relays are more reliable they should use them even if they had to charge more for the powerboard.
     
  18. MUTMAN

    MUTMAN Member

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    inrush isn't the problem, breaking under inductive load is (for old mech. relay)
     
  19. seb

    seb Member

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    THIS power meter looks like it is similar to the $170 Jaycar one and the Clipsal EzAudit $250 one.

    http://www.originecostore.com.au/efergy-wireless-smart-electricity-meter/HM01.htm

    $99

    I suspect my fridge is the culprit for my $700 power bill. It is 10+ years old and seems to play up a bit temperature-wise; I have a thermometer inside that I check regularly when I open the fridge to get something (don't open the fridge just to check the temperature...) and it seems to jump around a lot.
     
  20. Shion

    Shion Member

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    You might be pleasantly surprised. I've found the savings to be substantial since I started actively reducing my power usage about 3 years ago, using only simple measures such as those you've described. (Down from bills of $300+ to $150-180 per quarter in the share-house I used to live in, then miniscule bills as low as $30 per 2 months in the apartment I lived alone in after that.)

    Personally, I've found that the changes have made minimal difference to my comfort/lifestyle. I remember feeling silly for not having done this years earlier. :) Admittedly, even big energy savings translate to a relatively small benefit to the household budget, but that will change as power prices rise in the near future (and there's also the environmental benefits to consider).
     

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