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98 posts

Master Geek


  # 2278954 18-Jul-2019 13:14
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sir1963:

 

Rikkitic:

 

SirHumphreyAppleby:

 

Broken light also means light out :)

 

You need some sort of tool, even if there is some disagreement over what is suitable for the job. Older lighting installs often had phase connected while the swich was off, so you cannot assume it's safe. Personally, I don't assume anything is wired correctly.

 

 

Sorry, I was responding to the post before yours. When I have done this kind of thing in the past, I always switched whatever I was testing on and off a few times to make sure I was actually controlling the circuit. Yes, the light could suddenly burn out while being switched, but that is high on the list of improbabilities. Your meter could also break. If the circuit is turned off at the board, and the light goes out, then that fuse or circuit breaker is controlling that circuit. I think this discussion is approaching how many angels can dance on the head of a pin territory. Unlikely things can always happen so if you really want to be sure, then just switch off the mains altogether and hope lighting doesn't strike while you are replacing the fitting.

 

 

 

 

The "Correct" way to test with a multimeter is

 

Verify, test, verify .

 

So you verify the meter works correctly, do the test and verify it still works correctly.

 

Yes, the circuit breaker may control the phase, but it does NOT control the neutral, and if the neutral has been illegally wired so it is a back feed for another circuit it can be lethal , and yes I have come across this. NEVER trust the idiot who was there before you. And yes, I am a registered electrician.

 

My advice for home owners is to turn off the mains switch, and then STILL test between phase and earth and phase and neutral before and after.

 

 

 

 

Testing with an appropriate multimeter to ensure safe isolation before commencing repairs is still mandatory under ECP 51 anyway. Regardless of the advice of a number of highly qualified and experienced electrical professionals on this forum there are people who still think that cutting corners with electrical safety is perfectly fine. This appears to be because, based on their experience, they haven't been caught out yet so let's all follow their bad practices.

 

This scenario is just more proof that homeowners shouldn't have any exemptions at all.


1019 posts

Uber Geek


  # 2278994 18-Jul-2019 13:47
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Lizard1977: So the next question - fixing the light in the bathroom has thrown fresh light (pun intended) on how dim the single light fitting is in the main room of the sleepout, even with the brightest LED bulb available.  Is it possible to just swap out the single light fitting (ceiling mounted) with something like this with three lights instead of the single light?  Or is the wiring different for the two types of fitting?

 

Yes it is possible. It is good that you are familiar with the old/new colour codes, as these light fittings are usually done to the new standard so you will be converting between the standards when hooking it up. The occasional fixture pops up that is done to the USA colour codes (White=Neutral, Black=death=phase).

 

It is important with metal fittings such as this that you get the earth connected properly. If you stuffed up wiring on plastic single batten holders, worst case it doesn't work and blows the fuse. With metal fixtures, if you put phase to the chassis it will be immediately dangerous and if you don't connect the earth it will become dangerous at a random time in the future when a fault develops.  


 
 
 
 




1392 posts

Uber Geek


  # 2279075 18-Jul-2019 14:49
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Thanks for that.

 

Here's an illustration I drew to show the connection from the wall to the fitting.  The earth on the fitting side was a small metal "pole" that inserted into the connector and is connected to the chassis.  

 


595 posts

Ultimate Geek

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  # 2279142 18-Jul-2019 16:45
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Bung: Bunnings will be running the Australian line. The is no homeowner exemption there. You will come unstuck if the new fitting has an earthing terminal but your old wiring doesn't have an earth wire. To replace the existing fitting you may need a double insulated fitting. Check this before buying the replacement.

Edit It is bad practice to rely on turning off at switch. There may be live wiring still at fitting, the wall switch isn't real isolation and who knows someone could walk into the room and instinctively switch the light on.


Absolutely agree with this advise. I was fitting a new LED ceiling light in my sons room yesterday. He came in and turned on the switch. I was lucky on this occasion!!! Do yourself a favour and pull or flick off the fuse.

103 posts

Master Geek


  # 2280474 20-Jul-2019 21:52
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There is some bad advice in this thread. It is critical to both turn off appropriate breaker at mains and use a multimeter to validate that no voltages present. I’ve seen both earth and neutral faults than mean turning off the breaker doesn’t make the circuit safe. Most of the time it won’t kill you, but have a bad heart and if the current goes a particular path...

774 posts

Ultimate Geek


  # 2280575 21-Jul-2019 09:04
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BlueShift:

 

If you're the home owner, and you're replacing like with like, you don't need a sparkie.

 

You shouldn't need to turn off the main, as long as you turn off the wall switch to the light.

 

 

Correct. However I would turn the mains off anyway, or at least the circuit that controls that light. better to be safe, you never know if some kid or someone might come along and flick the switch back on while you are working.


894 posts

Ultimate Geek

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  # 2280592 21-Jul-2019 09:53
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zenourn: There is some bad advice in this thread. It is critical to both turn off appropriate breaker at mains and use a multimeter to validate that no voltages present. I’ve seen both earth and neutral faults than mean turning off the breaker doesn’t make the circuit safe. Most of the time it won’t kill you, but have a bad heart and if the current goes a particular path...

 

Agree 100% - my rule to anyone would be even the breaker isn't enough when your not an electrician turn the mains off, do it yourself don't ask someone (they might accidentally turn something other than the mains off) and verify with a multi meter.  Also nice to get a set of insulated screwdrivers.  Remember your not likely to be wearing boots rated for electrical hazards or have other things that will protect you compared to what an electrician uses if you make a mistake.

 

 

 

 


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