You can do that if you have a shunt. An ammeter is basically a voltmeter that reads the voltage as it passes through a resistor (the shunt) with a known resistance. The ammeter then displays the amps as converted by Ohm's law.

Excellent video, this is just what I needed to better understand how a shunt and an ammeter work together to measure current. Thank you for making this.

Thank you. learned more in your 3 minute video, then the last hour of research. Now I have a good direction to further study.

Hey thanks for this, buddy, I have to adjust the voltage regulator on my '61 Oldsmobile and this is needed, in conjunction with a load tester. This was a perfect video because like you said, those little ammeters come with no instructions. Cheers from MN!

Ah so I would have blown mine up almost instantly! That was helpful, thanks.

the only person i found explaining the shunt short and to the point. thanks alot..

I am not an expert. I do understand how many amps are being used and the importance of an amp gauge. Your video is very helpful. Thank you for being so simple in explaining it. Great video.

thanks man! very good of you to share your findings and knowledge. I want to do something very similar with a small power outage battery back. and you have helped me here.

Thank you this was great video may who ever above bless you for 2 burned up shunt, now we all can benefit from your exprience to not house catch fire . I really apricuate shearing your exprience sir. Its keeps me my family safer because of you thank you sir🙏😀.

Austin, current is measured in amperes and voltage is measured in volts. With your multimeter set to read voltage (say the 20v setting), putting the red positive lead on the positive side of a battery and the black negative lead on the negative side will give you how many volts the battery is pushing out. With your multimeter set to the 10A setting, you can measure amperage in the same way but only for a VERY short amount of time or you will burn out the leads. Less than 10 seconds.

Very well illustrated, thank you. Going to build a "car cooler" on steroids but want the whole thing to be reliable and not kill an 80ah battery. All of the decent ammeters I looked at were not through design but required a shunt. Thanks for the video.

last we my boss used 1.5mm gauge wire of about 30 meters long to hook up to 40/5 voltmeter and Ct but at a distance of 1 meter we were getting 14A on the ammeter and 0 at a distance of 30 meters . so i quickly measured the voltage and i told him sir , theres is a voltage drop . He said we are measuring Amps and you are talking about voltage. I got confused and didnt know what i could use to eplain to him. Now i can thanks ......And thats a shunt

Thank you very much for that very short, precise and informative video. Had an ammeter for some time and had no idea how to wire it in. Again, thank you.

Thanks for the share. May the force be with you

An ammeter shunt allows the measurement of current values too large to be directly measured by a particular ammeter. In this case the shunt, a manganin resistor of accurately known resistance, is placed in series with the load so that all of the current to be measured will flow through it. In order not to disrupt the circuit, the resistance of the shunt is normally very small. The voltage drop across the shunt is proportional to the current flowing through it and since its resistance is known, a voltmeter connected across the shunt can be scaled to directly display the current value. Shunts are rated by maximum current and voltage drop at that current. For example, a 500 A, 75 mV shunt would have a resistance of 0.15 milliohms, a maximum allowable current of 500 amps and at that current the voltage drop would be 75 millivolts. By convention, most shunts are designed to drop 50 mV, 75 mV or 100 mV when operating at their full rated current and most ammeters consist of a shunt and a voltmeter with full-scale deflections of 50, 75, or 100 mV. All shunts have a derating factor for continuous use, 66% being the most common. Continuous use is a run time of 2+ minutes, at which point the derating factor must be applied. There are thermal limits where a shunt will no longer operate correctly. At 80 °C thermal drift begins to occur, at 120 °C thermal drift is a significant problem where error, depending on the design of the shunt, can be several percent and at 140 °C the manganin alloy becomes permanently damaged due to annealing resulting in the resistance value drifting up or down. Here is some good reading on this. en.wikipedia.org/wiki/Shunt_(electrical)

thankyou for the video. So right the ammeter and shunt comes without any wiring instructions, so your instruct is greatly appreciated,regards collo

Dude, literally a perfect video of what I needed to see.

Thank you for explaining the connection, this cleared up my questions.

Thanks for keeping this to the point . Good job your time was appreciated.

thanks for simple and concise example. one can never be too careful when trying to measure 100's of amps (low voltage only, of course). thanks.

thank you this was exactly what i was looking for ;)

THANK YOU.. I BURNED 2 UP!! SO I FEEL YOU ON 3RD TIME LUCKY!! THANKS MATE!

Plain and simple, the best kind of video.✌

Thanks. It really helps to see a practical example.

Excellent / Excellent video you made there sir.

thanks so helpful and useful

Some instructions say to wire the shunt on the negative side of the load. Yours seems to work fine on the positive side.

Outstanding vid. Simple, easy to understand. Thank you!

Simple setup now i understand how it works , nice video.

thank you, thank you.. bought it from china. been looking an researching a days.

Excellent tutorial. Quick and to the point.

Thanks for taking the time to make the video. Very useful.

Thanks for sharing

Thanks LD it really help us to complete our project.

Good on ya mate, I found the video very helpful, thanks.

So the positive on the meter connects to the power supply positive And the negative meter out connects to the load positive ? Thank you

Fantastic video. Very informative. Thank you

Thank you for that demonstration.

Thanks bro, you saved me from burning the second meter

Thanks for some good info, i made the same mistake and killed my first gauge lol.

Thank you, I needed this basic refresher

Thank you. I need to put a shunt+Ammeter for 400kva UPS with for 415Volts, 200Ampere load. What should be the specifications for shunt and Ammeter

Thanks for the video. I couldn't find info any other place. Now my problem is finding a 10 amp / 1000 volt shunt. I think electronic instructors should caution their students about using them. All I have noticed is them saying to check the amps of a circuit connect the meter in a series.

Thank you very much. Very simple but very helpful video!!!!!!!!!

Super, thanks Cheers from the low countries

thanks for sharing...

You should be a teacher. This was just for what I was looking. You are right; no instructions. Shunt? Connect what to where? Now I know. Thanks.

This has helped me understand a shunt and how it works. Thank you.

Very Nice tutorial ordering a 100 amp/volt meter combo & shunt & definitely don't want to cook anything as I just destroyed one of my 50 amp power supplies accidentally.

Glad I watched this, that + - on the meter would have caught me out.

thank you this was exactly what i was looking

A Nice simple explanation, Thanks for posting.

Wow great video thanks it helped a lot in my test and cleared all my doubts

negative sensing wire!!!! thank you I almost fried my 48v solar battery bank!!!! Thank you again!!!

after 2 hours of searching :D finally someone that tells me wtf is that - on it :D :))

Great video and explanation.

thanks alot

Thank you a bunch. Great video and to the point. I like it.

Awesome bro..... directly to mind

How do you wire an amp meter without a shunt on a car? I have a diagram that says the negative wire goes to the amp meter but the diagram isn’t detailed enough to explain exactly how the amp meter should be wired. Does the negative wire go to the negative terminal? What do I do with the positive terminal? It doesn’t say on the diagram?

Thank you very much for the Information

rat mong cac i kien dong tren video nay,thanks

P's... think of each set of terminals as separate devices... Not one device. So if you just cut the shunt in half you will have the artery then one set (pair) of terminals (input to the meter) then the meter then the set of output terminals then the load then back to the battery. Do that on paper in that order and you'll see the matter is in series.

uma duvida! tenho um amperimetro analogico corrente ac alternada, 30 amper, e vou colocar em um aparelho bem forte, ( um chuveiro) seria nescessario colocar um shunt no amperimetro para guentar altas tensoes, ou pode ligar direto passando por ele sem frescura,? pode seguir a regrinha da soma de multiplicarr o valor de 220v x 30a = 6600w suportaria isso sem queimar o medidor, minha tensao aqui e de 220 volts?

Tks for sharing. o bough a HAU AMP 50a and do not want to use Shunt. The thing is the needle jumps to 50A when i plug a load of 1A. May the ammeter be deffective? tks

So for my automotive application that I'm looking at doing something like this for, I would need a 12V 390A shunt and meter? I'm running a 390A alternator hooked up to a 3000 watt inverter that I pull around 1500 watts AC and wanted to keep an eye on my amperage and voltage draw.

Thank you man. Thats what make me unsure.. The negative on the back.

FYI, Many speakers on KZfaq have a bad habit of smacking their lips while talking between sentences, try and refrain from doing this, it will improve your presentation skills. Thanks for the simple analogy on a circuit that includes an amp meter

My battery charger had the old ammeter with the sensor? encircled/wrapped around the negative cable. Is this a different system? Sorry I don't know what the terminology of the type I had. If I buy this style of ammeter with the shunt, as pictured in your video, does all the output have to pass thru the resistor, or does the resistor just protect the ammeter and allow unrestricted current to flow to the battery? Thanks in advance!

Thank you

thanks but from my understanding of measuring current you need to measure current in series and therefore you can take as much time as you want without damaging the fuse in the multimeter

Thanks so much for posting this! You are an awesome teacher :)

Thanks, that is all I needed to know.

hi, thanks for the vid, the only thing i cant figure out is what would be the load an a car be when only the ignition is on,( eg, were would i connect the load too presuming earth is just to earth ) would appreciate some help with this ? thanks again.

can you use the negative wire on the shunt instead of the positive like in your video?

Thank you very much. Exactly what I was looking for. Why don't the instructions come with the meter?!!?

thankyou you were a big help !!!

thanks’

Thank you.

Is it possible to install a Shunt on the the Negative Side of a 110V AC. To 12V DC. Converter to read the DC. Battery voltage , Current and Amperage of the system ?

so the amp meter, in order to work correctly needs a 75mA right? how can someone calculate what shunk he needs for a specific amp load?

Would you please tell me can I use the same Shunt to measure 12 Volt 45 AMP Car Battery?

Thanks that is what I want to know

I recently purchased an old Triplett 0-5 Amp AC meter on E-Bay and was wondering if the AC meter requires a shunt before installing it in series with the AC house line I also have ordered an AC 0-150 volt meter to go with it. I guess if it does I'll play hell getting the info on the milliamps and meter resistance. The voltmeter should be a nobrainer though. Thanks, Ed Allen

I have a 100v/500amp I want to use on my welding leads. So I would put the shunt in the positive welding lead to measure the amps?. But measure the voltage between the the positive and negative welding leads?

hello..! I made a testing rig to set the preset on some desire Current of my device. I want to replace my electric motor(10A, 220V, 2HP) by any other electric load. Can you suggest me which kind of load suites on my app.? Thanks.

Helpful video

you are measuring dc amps when inverter is truned on? How would hook up a dc amp meter , to measure amps, coming from your solar panels? Another question, measuring the dc amps going going too your battery bank? thanks

When do I need the shunt....for a solar charger in my Ford?

thank you.,i wish i could have seen your video before i burn my meter .,thanks for sharing

thanks for showing this , Question, since the Shunt has resistance, so we need to calculate with the resistance right ?

You have to use a shunt. The ammeter gauge will not work without one. The shunt decreases the amps that the gauge reads down to a safe level that will not damage the ammeter and then the ammeter calculates the real amperage by multiplication. The ammeter gauge itself does not read actual voltage, in other words. Unfortunately, you have probably fried your ammeter like I did.

Thank you for posting this L..

to measure amp from Solar panel, can I connect + panel to shunt and from shunt to solar + in solar controller and - panel goes directly to solar - in solar controller ?

So what caused the other two to burn up? Was it because you didn't have the shunt? Do you really need a shunt? How would you hook this ammeter to a AC 240v circuit?

In a DC circuit should the Ammeter or Load be connected to the Positive connector?

Thanks, good vid.

Thank You LDSerliance, I have a question, I'm trying to measure a 12-14DC Amp output with a multimeter that has a 10 Amp DC maximum tolerance. My question is the following: Can I use a shunt with a resistance or approximately 2 ohms and measure the DC Volts; once this is done, use Ohm's law to calculate the DC Amps? Once this is done, the DC amps that I measure using the shunt will be less than 10 amps. Then just work the backwards to find the DC Amps without using the multimeter. Would this work?

LDS, since the meter and shunt are essentially in parallel, can both sets of leads actually be on the meter and not the shunt ? I had a situation with a control panel the other day that was simple enough to do if this was OK but would be a rewire nightmare if not. I still have the "+" wire from the source going to the "+" side of the meter, the "-" wire from the meter going to the load. The Shunt is wired with separate leads from the meter in parallel. Gauge and meter specs match (0-25 ADC, 50 mV).

thank you