got a faulty light , checked all the connectios seems fine, got a multimeter but no instructions on how to use. should dial be set to volts or amps and which setting. should circuit be live or not. can i touch any connection with the red and black wires or red to red and black to ? please help because her indoors is annoying me to fix this light thanks
multimeter help
- Thread starter dally
- Start date
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B
breezer
you say faulty light, is it the light fitting itself?
is it wall / ceiling mounted, have you recently fitted it.
and where did you get the meter?
is it wall / ceiling mounted, have you recently fitted it.
and where did you get the meter?
Has the light worked at any stage in the past?
If the circuit isn't live, it won't make any difference whether you set the meter to volts or amps, as it won't move from zero.
You could, if the meter has a 'resistance' scale, use it to check continuity in the cables to and from supply to switch to lamp; the circuit should definitely NOT be live when you do this.
If checking voltage, it should be connected in parallel with the circuit under test - i.e across the points where you want to measure the presence of voltage. You're not really interested in checking current (amps) since you don't really need to know how much current is being drawn (if any(, just whether or not you're getting voltage to the unit.
If you're still not sure, check in again here before you start......
As someone said, where did you get the meter and what make is it?
Regards, Graham
If the circuit isn't live, it won't make any difference whether you set the meter to volts or amps, as it won't move from zero.
You could, if the meter has a 'resistance' scale, use it to check continuity in the cables to and from supply to switch to lamp; the circuit should definitely NOT be live when you do this.
If checking voltage, it should be connected in parallel with the circuit under test - i.e across the points where you want to measure the presence of voltage. You're not really interested in checking current (amps) since you don't really need to know how much current is being drawn (if any(, just whether or not you're getting voltage to the unit.
If you're still not sure, check in again here before you start......
As someone said, where did you get the meter and what make is it?
Regards, Graham
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Somebody once posted a link to a website which told you how to use a meter - can't remember who, though, but maybe they'll do it again.
B
breezer
i would say it is either a loose / bad connection or its a disco light and its meant to flicker.
have you checked / changed switch? i take it is an on / off switch as opposed to dimmer switch? what type of lamps does it have? (flourescents will flicker when old)
have you checked / changed switch? i take it is an on / off switch as opposed to dimmer switch? what type of lamps does it have? (flourescents will flicker when old)
tips on using a multimeter.
1: current measurement is little use when doing electrical work for two reasons firstly you have to insert the meter rather than just probing (which is a pain to do) secondly many multimeters can't measure very high currents anyway especially in AC mode (for example my meter has a 10A DC range but the AC range stops at 250ma),
2: resistance measurement is for checing how well current can flow through things on a dead cuircuit. DO NOT use the resistance range on a live cuircuit, with ELV stuff you might get away with doing it without frying your meter with mains i doubt you will be so lucky.
3: voltage measurement. This is for use on live systems and therefore obviously requires great care when working on mains. Also most digital multimeters have an extremely high imput impedance and will measure voltage on a core that is isolated and running alongside live cores. also whilst i have never tried it apparently you can get a reading by sticking one probe on a live terminal and the other against the wall.
4: ranges such as diode and transistor test are not at all relavent to mains wiring.
5: make sure you use the right sockets. Most multimeters have more than two sockets and it varies which sockets you need to use for which functions this is usually marked on the meter.
1: current measurement is little use when doing electrical work for two reasons firstly you have to insert the meter rather than just probing (which is a pain to do) secondly many multimeters can't measure very high currents anyway especially in AC mode (for example my meter has a 10A DC range but the AC range stops at 250ma),
2: resistance measurement is for checing how well current can flow through things on a dead cuircuit. DO NOT use the resistance range on a live cuircuit, with ELV stuff you might get away with doing it without frying your meter with mains i doubt you will be so lucky.
3: voltage measurement. This is for use on live systems and therefore obviously requires great care when working on mains. Also most digital multimeters have an extremely high imput impedance and will measure voltage on a core that is isolated and running alongside live cores. also whilst i have never tried it apparently you can get a reading by sticking one probe on a live terminal and the other against the wall.
4: ranges such as diode and transistor test are not at all relavent to mains wiring.
5: make sure you use the right sockets. Most multimeters have more than two sockets and it varies which sockets you need to use for which functions this is usually marked on the meter.
If you're using a digital meter you'll see that the voltage reading will fluctuate if it's "pick up". In the hands of someone who's got some experience and knowledge they'll know what they're looking at. It's all a question of understanding. Please don't start the neon screwdriver debate again!!
No no no Shaggy I think you are plonker pulling, n'est pas?
The multimeter will tell you the actual voltage, e.g. if it is at 240V - and about to kill you - or inductive pick-up (a few volts say) and possibly survivable.
.....but only if you have the thing set to measuring voltage, at the correct range setting, with the leads in the correct sockets (as Plugwash says).
I think you are plonker pulling, n'est pas?The multimeter will tell you the actual voltage, e.g. if it is at 240V - and about to kill you - or inductive pick-up (a few volts say) and possibly survivable.
.....but only if you have the thing set to measuring voltage, at the correct range setting, with the leads in the correct sockets (as Plugwash says).
Me? I was trying to make a serious comment. As you say, if the user doesn't connect the multimeter correctly then could get no reading on a live cable. I think the same inexperienced guy has a good chance of using a neon screwdriver and showing a voltage. This really is a safety issue and anyone who asks how to use a meter may have a go and make a mistake.
(not that I wish to start the excellent neon thread again of course)
I was trying to make a serious comment. As you say, if the user doesn't connect the multimeter correctly then could get no reading on a live cable. I think the same inexperienced guy has a good chance of using a neon screwdriver and showing a voltage. This really is a safety issue and anyone who asks how to use a meter may have a go and make a mistake.(not that I wish to start the excellent neon thread again of course)
Agreed 'tis easier to cock a measurement and misinterpret the results with a complex piece of equipment, than the 'go/no go' indication from something simpler.
(note that I craftily avoided mentioning what the simpler thing might be .....)
'tis easier to cock a measurement and misinterpret the results with a complex piece of equipment, than the 'go/no go' indication from something simpler.(note that I craftily avoided mentioning what the simpler thing might be .....)
got a multimeter but no instructions on how to use
I stand to get flamed for this but on reading the initial post, my reaction was to tell the poster to stick the multimeter where some people think everyone else should put their neon screwdriver
I am aware that this is a DIY help forum, but where do you draw the line
I do not believe that anyone can teach someone how to use a multimeter SAFELY in a couple of sentences, never mind instruct them how to use it to fault find
I know all the electricians on this forum do their very best, sometimes under very trying circumstances, to give good advice, but they must always think "what if the guy follows this and I have left out something vital, and as a result he gets injured "
Morally, if not legally, this must always be of concern
I served a four year apprentiship and spent four years in college getting a HNC and sometimes wince when I read some of the questions asked here
I am currrently renovating my bungalow
This has involved wiring, rough block work ( to fill in old doorways ) carpentry, plasterboarding, laying carpets and wood flooring, foundation laying for a conservatory and concrete flooring/screeding BUT I got a corgi registered plumber to put in my new central heating system
I was told during my apprentiship that if I could run conduit including using a bender and sweating flexible conduit joints, I could plumb in a water system but COULD I DO THIS SAFELY. I dont know the regs so leave it to the experts
got a multimeter but no instructions on how to use - BIN IT
I stand to get flamed for this but on reading the initial post, my reaction was to tell the poster to stick the multimeter where some people think everyone else should put their neon screwdriver
I am aware that this is a DIY help forum, but where do you draw the line
I do not believe that anyone can teach someone how to use a multimeter SAFELY in a couple of sentences, never mind instruct them how to use it to fault find
I know all the electricians on this forum do their very best, sometimes under very trying circumstances, to give good advice, but they must always think "what if the guy follows this and I have left out something vital, and as a result he gets injured "
Morally, if not legally, this must always be of concern
I served a four year apprentiship and spent four years in college getting a HNC and sometimes wince when I read some of the questions asked here
I am currrently renovating my bungalow
This has involved wiring, rough block work ( to fill in old doorways ) carpentry, plasterboarding, laying carpets and wood flooring, foundation laying for a conservatory and concrete flooring/screeding BUT I got a corgi registered plumber to put in my new central heating system
I was told during my apprentiship that if I could run conduit including using a bender and sweating flexible conduit joints, I could plumb in a water system but COULD I DO THIS SAFELY. I dont know the regs so leave it to the experts
got a multimeter but no instructions on how to use - BIN IT
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