Using a multimeter

DIY_Johnny · Post by **DIY_Johnny** » Wed Sep 09, 2009 8:53 pm

Right from my post below on testing a live wire, I have dug out my old Multimeter (batteries still work - hasn't been used in 7 years at least!!!)

I have no clue how to use it to test a live wire and don't want to try until I run it past you guys.

It says in the instructions that it can measure AC current and Voltage but doesn't say which V what is for AC Voltage, similary with current

Any advice gratefully received!!

Post by **ultimatehandyman** » Wed Sep 09, 2009 9:13 pm

I have labelled up what each section is for apart from the small area at the top right, I can't make out what that is.

To Measure mains voltage, place the black lead in the com socket and the red lead in the V/ Ohms socket.

Then turn the dial to point to AC volts 700 then you should be able to take a reading.

Extreme caution must be exercised when testing live wires and if possible it is best to test with the electricity switched off.

What exactly are you trying to test?

deck · Post by **deck** » Wed Sep 09, 2009 9:19 pm

Live testing on something that not been used in seven years. Todays part p meters have to be checked and calabrated every year.
Buy something more up to date and more easy to understand. Theirs loads on the market for diy and pros alike
Deck

DIY_Johnny · Post by **DIY_Johnny** » Wed Sep 09, 2009 9:24 pm

Excellent cheers mate.

I was following on from scruffs comments in my previous post that the screwdriver volt meters are not great to use. I have busted it anyway!

I simply want to test if there is electricity flowing through a fused spur that you advised me on a week or so ago. The FCU is feeding undercabinet lightening in the kitchen and so comes from the sockets

Usually I turn off the electricity off at the mains when changing sockets but sometimes I can't see a thing so I leave the lighting circuit on and switch off the circuits from the sockets.

Where do i actually place the leads UHM

Deck,
just saw you post, given my simple requirement, do you think I can use this thing instead of a screwdriver volt meter?

DIY_Johnny · Post by **DIY_Johnny** » Wed Sep 09, 2009 9:36 pm

Top part is like this, (not worried about it though)

Been p*ssing about testing batteries , numbers are begining to make sense, its just a scaling thing i assume

deck · Post by **deck** » Wed Sep 09, 2009 9:36 pm

Hi Newbiejohn
What is it you want to test in your kichen
Deck

DIY_Johnny · Post by **DIY_Johnny** » Wed Sep 09, 2009 9:44 pm

more of a general comment on how to test for a live wire Dave so I don't electrocut myself

Just if the wire is live before I replace the light switch. I know it isn't but I like to give it a quick check in case I switch the circuit back on at the fuse box and it slips my mind to switch it back off

Mooncat · Post by **Mooncat** » Wed Sep 09, 2009 9:47 pm

The section shown here is for testing transistors. You have to identify the type NPN or PNP, and the lead arrangement, plug it in and the meter will indicate the gain.

deck · Post by **deck** » Wed Sep 09, 2009 9:56 pm

Hi newbiejohn maybe what you require is a voltage stick a simple wand that glows when mains voltage present
Hope this helps
Deck

thescruff · Post by **thescruff** » Wed Sep 09, 2009 10:50 pm

deck wrote:Hi newbiejohn maybe what you require is a voltage stick a simple wand that glows when mains voltage present
Hope this helps
Deck

Why he has a perfectly good multimeter.

sparkydude · Post by **sparkydude** » Thu Sep 10, 2009 5:09 am

a volt stick has its uses but not in this situation, the multimeter he has is perfectly useable but the only thing i would say is change the leads for a set of fused leads to protect yourself, i had a meter like that when i first started out doing DIY electrics and had no problems with it, But the leads were cheap and nasty and had long exposed tips about 10mm or more which were pretty dangerous when testing live terminals close to each other. Maplins sell a decent range of leads not to expensive either .

Nick

DIY_Johnny · Post by **DIY_Johnny** » Thu Sep 10, 2009 7:30 am

Thanks Nick, your right, never thought of that. the tips are about 3 inches long and bare.

So when testing to see if a wire is live, where do I place the tips?

dewaltdisney · Post by **dewaltdisney** » Thu Sep 10, 2009 7:54 am

I must admit I have a Maplin Multimeter and I have not a bleeding clue how to use it. The instructions are shite. I wanted to test some wiring on my tractor but did not know how to set it up.

Perhaps we need a UHM vid to show us basics

DWD

sparkydude · Post by **sparkydude** » Thu Sep 10, 2009 4:48 pm

To test if the terminals are live then you need to test between live and neutral then live and earth and then neutral and earth just to prove that all cores are dead.

Nick

DIY_Johnny · Post by **DIY_Johnny** » Thu Sep 10, 2009 4:51 pm

Hello nick, so to be sure I have this right

1) Its Red lead on Live, black lead on Neutral, reading should be ~240V
2) Its Red lead on Live, black lead on Earth, reading should be ~240V
3) Its Red lead on earth, black lead on Neutral, reading should be ~0V

Have I understood this correctly?