Why did my multimeters blew up? (AC voltage)

[evlo]

I tried to measure AC VOLTAGE, 100% sure multimeter was set to AC voltage, i even have eye witness.

I tried to measure between L1 and L2 - result: spark, house elcb down, mutimeter does not measure. Hopefully fuse, it was my good meter.

So now, second meter AC voltage, unfussed between L1 and PE, same thing, spark, house main elcb down.
 
I was fault finding my installation, fault was not connecting Neutral wire to the distribution rail. I was doing measurements on the wires coming right from the electrical company  meter. Nothing after that was connected.

3 phase 230V connection.

[Grandchuck]

Can you supply a photo showing the leads plugged into the meter?

[schmitt trigger]

Please provide meter's brand and model number.
A photo of the damage inside would be nice, although not strictly necessary.

[CaptDon]

Probably had the leads connected to meter COM and AMP inputs. Surely did something wrong! If the meter was indeed set to A.C. Volts and not A.C. Amps then you had the meter leads plugged into the wrong holes.

[IanB]

I tried to measure AC VOLTAGE, 100% sure multimeter was set to AC voltage, i even have eye witness.

This is not sufficient to avoid mishaps. You also need to ensure the test leads are plugged into the right sockets on the meter. Some good meters will warn with an alarm if you plug the leads into the wrong sockets for the measurement.

[pcprogrammer]

Probably had the leads connected to meter COM and AMP inputs. Surely did something wrong! If the meter was indeed set to A.C. Volts and not A.C. Amps then you had the meter leads plugged into the wrong holes.

Sounds like the most likely fault. A normal multimeter set to AC volts and connected properly should not cause a short.

Some newer ones have mechanical protection to prevent such a fault. My old Agilent has an electronic warning setup for this. With the test lead inserted in the A connection it will buzz and show Aerr on the screen when dialed onto anything other then the A settings. Does not give the warning on the mA connector though.

[golden_labels]

Also mind that amplitude between any two phases is around 600 V in 3-phase 230 V network. I did see DT83x family members rated for less than that.

[evlo]

well i did measure 230V and even 400V in some wall sockets before, and pretty sure i did have it plugged in com the normal "20A" socket. I do not think there are special slots for the leads for AC volts.

The good one is owon ow18E



pretty sure it was connected to com and 20A and than sparks



It is possible that the times i did measure the 400V and 230V I did use different meters, well it is very probable. Now I'm very confus.


I did tried the com + V but that was ... too late I guess maybe just the probes might have burned out.




Other meter is this one
https://shop.fkt.cz/digitalni-multimetr-fk8550-ean7120272-skupsf0000000005.php - here I would guess that I used the "V", but at the moment I was very confused about how everything is behaving, so I'm not sure.
This one does have backlight toggle, no timeouts, etc. As interesting quirk.

I usually use owon and have leads in "20A" and COM "holes" (ports?) and it does continuity and voltage etc. for DC in that setup, maybe I should use the other hole for that and that 20a is for current measurement, really, but until now it always worked ....



Also I'm still very confused, how 230v LED "bulb" can turn on when it is only connected to N and L1 lead, but the N leads is never ever connected to anywhere final, like PE, just to the air. Well it does turn on for a bit and then dies. But still, i measured, between N and L1, hopefully correctly that time about 0,8V, so how can it light up?

[Veteran68]

well i did measure 230V and even 400V in some wall sockets before, and pretty sure i did have it plugged in com the normal "20A" socket.
...
pretty sure it was connected to com and 20A and than sparks

Then that is exactly your problem, as others have pointed out. You had the leads plugged into current measuring socket, not the voltage socket (the socket to the far right). By measuring from live to PE or live to neutral, you've shorted out the meter. Hopefully you only blew the fuse(s).

[evlo]

But still weird that when I use it for continuity, ohms, etc. I would not use the slot that is marked for that, maybe I just got confused by what people here are writing. Should it even measure ie. DC resistance when connected to "20A"?

[Gyro]

Probably a really good (actually, overdue) time to read the manual. It's all set out clearly there.

Edit: It's not possible for you to have been measuring continuity, voltage, etc. via the 20A jack as that would be connected to the COM jack by the very low resistance high current shunt and fuse.

[ArdWar]

I usually use owon and have leads in "20A" and COM "holes" (ports?) and it does continuity and voltage etc.

This doesn't make any sense at all.

Granted electrometer-type current sensing in theory can do that but I'm pretty confident that 99.999% of handheld DMM ever made is not that.

I also pretty confident that 100.00% of them can't do voltage and continuity from 20A port.

Some serious misunderstanding is definitely on play here.

[wraper]

[BeBuLamar]

Replace the fuse in the meter then try to measure resistance with it and see.

[wraper]

Replace the fuse in the meter then try to measure resistance with it and see.

That fuse is only relevant to current range. The rest is completely separate. Condition of the fuse does not affect any measurements other than current.

[IanB]

well i did measure 230V and even 400V in some wall sockets before, and pretty sure i did have it plugged in com the normal "20A" socket. I do not think there are special slots for the leads for AC volts.

This is a huge mistake on your part. You do not ever want to plug the test lead into the 20 A socket, or even the μA mA socket, unless you are an expert who knows exactly what you are doing. You always plug the red lead into the VΩHz socket. You should put tape over the other sockets to prevent you from plugging into them again.

[tunk]

And stay far away from high voltage until you have learned far more. It can be fatal.

[amyk]

I like how everyone immediately identified, and the OP confirmed, the cause of this.

The 20A and uA mA sockets are for measuring current only, not voltage.

Please do read a bit more on how your meter works before using it!

[CaptDon]

Unbelievable how anyone would plug a lead into the current jack to measure volts!!! Buy a couple more meters and measure how many OHMS your power company has. Second thought......DON'T!!!

[xrunner]

And stay far away from high voltage until you have learned far more. It can be fatal.

A good "tip for young players" as has been said around here. 

[themadhippy]

And stay far away from high voltage

Not just high voltage,but high energy .12v sounds harmless enough,until its able to kick out a few hundred amps,it might not kill you,but  at the very least your going to need some clean underwear if you accidentally short it out

[BennoG]

The previous measurements of the OP where probably done between the 2 outermost jacks.
so the 20A and the Volt Ohm connector.
Because the 20A is connected to the COM the measurement worked as expected.

He later used the com jack and blew the meter.

Benno

[pcprogrammer]

Replace the fuse in the meter then try to measure resistance with it and see.

That fuse is only relevant to current range. The rest is completely separate. Condition of the fuse does not affect any measurements other than current.

Yep, but I guess BeBuLamar was hinting that it would show impossible to measure resistance or continuity with the leads in 20A and COM connections, like the OP was sure he had done before.

The OP can count his blessings that nothing bad happened while measuring directly after the power companies meter on two phases. Fused at maybe 64A it will have been quite the blast. The fuse in the meter might not have helped against damage caused by the flash, but maybe the fuse contained it. Only way to know for sure is to open up the meter and see.

A simple test to see if the meter survived is to plug the leads in the proper connectors, COM and V..., The two connections on the right side of the meter and turn it on to continuity and see if it beeps when the probes touch each other.

[Doctorandus_P]

Unbelievable how anyone would plug a lead into the current jack to measure volts!!!

Not unbelievable at all. First, there is the ignorant, who have not read the manual or know much about electronics or DMM's. Second, there is simple user error or absent mindedness. This mistake is so common that most of the "better quality" meters have a protection against exactly this mistake. A few have a mechanical interlock, which covers those banana plug holes when the meter dial is in a non-current measurement mode. But far more common is that the DMM turns on the beeper when a cord is jacked into an amps socket when it should not be. The first meter I bought with this feature (Dynatec 112) is now in my possession for over 30 years, and in that time it has saved a bunch of meter fuses.

[GLouie]

Confirming, as BennoG noted, that on some meters you can get volt and ohm readings with the probes in the high Ampere jack and the V-Ω jack. An Aneng 8008 will do this, but the EEVBlog-Brymen beeps an error with this configuration. OP thinks it was COM and 20A, but must be mistaken.