Replacing a pull switch for an extractor fan
- Thread starter Pearlyman
- Start date
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I've just done as described above and I've tested the wires that will connect to the fan...
The red, blue and yellow are all showing as live - regardless of whether the switch is on or off !
I'm no expert (!) - but this doesn't strike me as right !!
Any suggestions for where the problem might be...?
That depends what you are using to test it.
The normal 'neon screwdrivers' (which you touch the end of the handle to detect voltage) are not reliable.
There are newer ones (which you do NOT touch the end of the handle to detect voltage) which are just as unreliable.
Unless you are using a proper two lead voltage detector to a known earth you cannot be sure the wires are actually live - and, more importantly, - dead
Without the proper test equipment it is difficult to know what else to suggest.
The normal 'neon screwdrivers' (which you touch the end of the handle to detect voltage) are not reliable.
There are newer ones (which you do NOT touch the end of the handle to detect voltage) which are just as unreliable.
Unless you are using a proper two lead voltage detector to a known earth you cannot be sure the wires are actually live - and, more importantly, - dead
Without the proper test equipment it is difficult to know what else to suggest.
I am using a neon screwdriver to 'test' things...
In fairness, I've used the same method for each step I've taken so far: connect up and then test using the screwdriver - and the previous results were exactly as I would have expected...
With the permanent live attached, I've check each of the connections in the switch and L1 & N for both supply & load, appear to be live (based on the screwdriver test).
I do have a 'rapitest' power tester, which has 2 metal points, joined by a piece of wire (apologies for the lack of a technical description !). At one end, it appears to be able to tell me whether I'm connected to 110, 220, 240 or 380V.
Is there some way I can use it to test what is live ?
What are the chances of the switch being faultty (unlikely, I guess)
If I connected up the fan (ignoring the 'test') is it likely to blow if the wires are live as I described..?
I appreciate you are operating in the dark a bit here - but I'm grateful for your best efforts.
In fairness, I've used the same method for each step I've taken so far: connect up and then test using the screwdriver - and the previous results were exactly as I would have expected...
With the permanent live attached, I've check each of the connections in the switch and L1 & N for both supply & load, appear to be live (based on the screwdriver test).
I do have a 'rapitest' power tester, which has 2 metal points, joined by a piece of wire (apologies for the lack of a technical description !). At one end, it appears to be able to tell me whether I'm connected to 110, 220, 240 or 380V.
Is there some way I can use it to test what is live ?
What are the chances of the switch being faultty (unlikely, I guess)
If I connected up the fan (ignoring the 'test') is it likely to blow if the wires are live as I described..?
I appreciate you are operating in the dark a bit here - but I'm grateful for your best efforts.
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Yes. Set meter to 240V (AC - NOT DC) put the black probe on the earth wire (assuming it is connected to earth) and in turn touch the red probe on each of the terminals of the switch to test for 240V.
Obviously the load L should only register 240V when the switch is on.
The N supply should register 0V but there may be a few volts present.
Not impossible. Many hours wasted assuming NEW parts are good.
If you want to, remove the switch, set the meter to lowest Ohm (Ω
setting (beep ?) and put the probes on L supply and L load and operate the switch. Beep when on - No beep when off.Do the same with the N terminals.
No. IF they are all live nothing will happen but it is not likely they are.
The danger is connecting a live to a neutral and then switching on.
My Rapitest tester is a bit simpler than you've given it credit for being..!
It just consists of 2 black probes, linked by a wire - there is no ability to set it.
I think you are supposed to put the 'plain' probe on the earth and the probe with the indicators on the 'live'. When I do this however, it gives no reading.
I therefore guess that the tester isn't working - though I could possibly be using it incorrectly (maybe I should put the probes on the live and the neutral ?).
Anyway, I feel I'm now a little out of my depth, so I'm going to call in some professional assistance...
I hate to be beaten by this - especially when I think it should be quite straightforward - but something is not quite right and I can't figure out what it is...
I can afford to wait a few days, so that's not a problem - and I promise I will post the solution - whatever it turns out to be...!
It just consists of 2 black probes, linked by a wire - there is no ability to set it.
I think you are supposed to put the 'plain' probe on the earth and the probe with the indicators on the 'live'. When I do this however, it gives no reading.
I therefore guess that the tester isn't working - though I could possibly be using it incorrectly (maybe I should put the probes on the live and the neutral ?).
Anyway, I feel I'm now a little out of my depth, so I'm going to call in some professional assistance...
I hate to be beaten by this - especially when I think it should be quite straightforward - but something is not quite right and I can't figure out what it is...
I can afford to wait a few days, so that's not a problem - and I promise I will post the solution - whatever it turns out to be...!
You can get a useful multimeter without breaking the bank.
http://www.toolstation.com/shop/Hand+Tools/Electricians+Tools/Digital+Multi+Meter/d10/sd170/p11867
You can't do electrical work without one.
Third in line after the screwdriver and scissors.
http://www.toolstation.com/shop/Hand+Tools/Electricians+Tools/Digital+Multi+Meter/d10/sd170/p11867
You can't do electrical work without one.
Third in line after the screwdriver and scissors.
Cheers - I'll get one of those regardless...
My next door neighbour is a commercial electrician and he's said he'll have a quick look/check. I think that's all I need to be honest: just for someone to say the switch is OK (or otherwise).
My guess is that if I connected the fan, it would work. However, the 'testing' has put some doubts in my mind - and I'd rather be safe than sorry.
I always find this kind of thing quite interesting anyway. I like to try and understand how things work - even though I'll never be an expert(certainly not with electrics, anyway )...
My next door neighbour is a commercial electrician and he's said he'll have a quick look/check. I think that's all I need to be honest: just for someone to say the switch is OK (or otherwise).
My guess is that if I connected the fan, it would work. However, the 'testing' has put some doubts in my mind - and I'd rather be safe than sorry.
I always find this kind of thing quite interesting anyway. I like to try and understand how things work - even though I'll never be an expert(certainly not with electrics, anyway
)...
This is a better one.
http://www.test4less.co.uk/details....Fluke 1653B Multifunction Installation Tester
Probably wisest.
Yes but I'm not allowed to suggest the BANG test method.
Perhaps neighbour will show you how to do it.I always find this kind of thing quite interesting anyway. I like to try and understand how things work - even though I'll never be an expert(certainly not with electrics, anyway
I fear that one would be wasted on meThis is a better one.
http://www.test4less.co.uk/details....Fluke 1653B Multifunction Installation Tester
It is very tempting to just wire it up and try it - but I'm resisting !!
Like I said, I'm in no rush, so a couple more days will make little difference.
I've found the same multi meter for sale with Amazon - and they don't charge me postage.
A fiver well spent, I think
This looks ideal for a household starter set - multimeter, voltage indicator and dedicated continuity tester, all in a handy case: http://www.amprobe.eu/de_DE/showproduct/115/Junior-Set/I fear that one would be wasted on meThis is a better one.
http://www.test4less.co.uk/details....Fluke 1653B Multifunction Installation Tester
PDF brochure: http://www.amprobe.eu/de_DE/downloadfile/115/beschreibung_1/
All in German, unfortunately, as is the blurb on each product:
Multimeter: http://www.amprobe.eu/de_DE/showproductdata/487/Hexagon_55/
Voltage indicator: http://www.amprobe.eu/de_DE/showproduct/116/2000_α_(alpha)/
Continuity tester: http://www.amprobe.eu/de_DE/showproduct/481/TESTFIX/
but it is sold in the UK - the company is now owned by Fluke, and I guess they haven't got all the websites sorted out yet - contact them (http://www.fluke.co.uk) for info on where to buy.
Right now the English specs are still lurking on the Internet Time Machine from when Beha was an independent company:
http://web.archive.org/web/20060920022629/http://www.beha.com/files_uk/multimeter/93549.pdf
Also see another discussion here: //www.diynot.com/forums/viewtopic.php?t=26282 It's a few years old, so specific model number advice may be obsolete (and prices will be higher), but the generic advice is still sound.
My neighbour called round yesterday evening and got the fan working...
It had been wired up correctly - the problem was with my tester (which he also suggested I threw away - LOL !).
When he tested the circuits properly, the yellow (live switch) was showing around 40V, which he said was 'pick-up' from the permanent live.
The blue was not required (as it was a neutral for the now non-existant neon indicator in the old switch) whilst the black was required as a neutral for the fan and was being picked up from the ceiling rose.
In short therefore, he didn't really need to come round, as the explanation/directions from the forum (or more specifically EFLImpudence) were spot on.
Thanks again for the help.
It had been wired up correctly - the problem was with my tester (which he also suggested I threw away - LOL !).
When he tested the circuits properly, the yellow (live switch) was showing around 40V, which he said was 'pick-up' from the permanent live.
The blue was not required (as it was a neutral for the now non-existant neon indicator in the old switch) whilst the black was required as a neutral for the fan and was being picked up from the ceiling rose.
In short therefore, he didn't really need to come round, as the explanation/directions from the forum (or more specifically EFLImpudence) were spot on.
Thanks again for the help.
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