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I'm in the process of building a little grow cupboard for herbs and vegetables and want to make a row of 24-30W CFL's (compact flourecent lights) and have found these plug adapters:

http://pages.ebay.com/link/?nav=item.view&alt=web&id=281689827872

Are these safe to plug 5 of these into a power board that has a safety switch?

If not, can anyone suggest a safe alternative? I want to use multiple lower wattage bulbs instead of a few high output bulbs.

Thanks in advance!

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It's all about the watts, dude!

The safety concern surrounding the use of adapters, power boards, and the like is as you mentioned: wattage.

Power strip (board) safety 101:

  1. Add up the wattage of all loads (in your case, CFLs) plugged into the power strip.
  2. Look at the power strip for a wattage rating, and take four-fifths (or 80%) of it as a derating factor to prevent the safety switch (circuit breaker) from nuisance tripping.
  3. Compare that four-fifths-of-the-rating number with the total wattage of your loads; if it's less than that, you're good to go! If it's greater than that, you need to use more than one power strip/tap/board plugged into different outlets, or even multiple circuits coming from the panel.

Using a 1200W (240V 5A or 120V 10A) power strip/board and your example load of 5 30W CFLs:

  1. The total load is 5*30W = 150W
  2. The power board is rated for 1200W -- but we don't want to push it that far; the 80% is a derating factor as fuses and circuit breakers aren't exactly fans of operating at their rating continuously. So, 80% of 1200W is 960W.
  3. Since 960W (the amount of power the board should be handling on a continuous basis) is well over 150W, you are fine.
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  • Wow, thank you so much for that info! So if using multiple powerboards and plugging those into a larger powerboard, I'll obviously need to add up the total wattage of ALL the lights plugged into that larger powerboard, yeah? Would you happen to know the amp rating in a single Australian wall socket? Thanks again, it is greatly appreciated!
    – DommyCastles
    Commented May 12, 2015 at 23:33
  • @DommyCastles -- you'd need to add up the wattage of all the lights plugged into that larger powerboard, yes :) and typical AS 3112 sockets are rated for 10A. Don't forget to upvote/accept the answer!
    – ThreePhaseEel
    Commented May 12, 2015 at 23:51
  • @dommycastles I dont know the laws where you live, but there may be fire safety laws that prohibit chaining powerbars like that, reguardless of the total power draw.
    – Grant
    Commented May 13, 2015 at 3:10
  • @Grant -- the way he's talking -- he's talking about a star configuration, which is how you're supposed to handle the "I need lots of oulets for low-current loads" case vs. daisy-chaining power strips, which isn't really an ideal way to do things in any case (I'm not sure how said anti-electrically-illiterate laws regarding powerbars handle star configurations, myself...)
    – ThreePhaseEel
    Commented May 13, 2015 at 3:16
  • @threephaseeel Where I live in Canada, at least on commercial property (not sure about residential) plugging one powerbar into another, or into any other kind of outlet splitter, will get you a stern talking to by the fire inspectors. Supposedly from the risk of increased resistance at each connector. Silly as it might be, if you want more outlets they expect you to get a very large powerbar or install more outlets in the wall.
    – Grant
    Commented May 13, 2015 at 3:20

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