Multimeter recommendation?

[Kansas_couple]

I'm looking to buy a multimeter, as my rig's refrigerator doesn't work on electric but still works on gas. There is power to its outlet (of course, that would be too easy of a fix..) and I know my next steps will involve going to the circuit board. I'm looking at the Klein Tools multimeters they sell at Home Depot. Noticed the CL 390 can measure DC amperage. Would this be something to have, or is measuring DC current not that important? If not, then I'd go with one of the less-expensive models. I'm open to thoughts and input. Thanks!

[theoldwizard1]

CA Traveler wrote:
A small 12V test light with ground wire, bulb and probe is a very useful tool because it's very visual and it puts a small load on the circuit.

TRUE ! There are some "tricks" you need to learn to get the maximum out of it. Get one that use an incandescent bulb, NOT an LED ! Some auto techs use a dual filament tail light bulb just because it can draw more current.

For a meter, decent middle of the road clamp meter, Uni-T UT210E.

[wa8yxm]

There are many meters that will do most of what you are able to use starting at around 5.00 at harbor freight... NOW.. These measure AC and DC current usually up to around 10 amps. AC and DC voltage.. Most are peak reading meters on AC then multiply by Square Root(2)/2 (.707) to give you RMS voltage... This is good so long as it's a clean sine wave...

More expensive meters actually do the math and compute the RMS.. but you do not often need that (if you get strange voltage readings on a MSW inverter... that's when you need the better meter. about the only time)

More expensive meters add Frequency (Useful) Temperature probes. (Usefull but less so) and other features (Ability to test some components, measure capacitors and such).

Then there are clamp on ammeters. These often can read up to 400 amps on the clamps (you do not need to insert them in the curcuit just clamp it over say a battery cable.. Most of these the clamp only does AC. came in handy to figure out what was going on with an Air Conditioner (20 amp range)

Some can do both AC and DC on the clamp (mine) It cost about 65 bucks and is a Craftsman model. The "Gold Standards" are Simpson and Fluke. But again you don't need that good. (just the carry case for a fluke is almost what I paid for my crafstman and it has no electronics.. Just plastic)

I've got meters up to around 250 dollars list... But Electronics is .. My hobby.
(Among other entries I'm a certified electronics technician and extra class ham radio operator) Actually other than ruggedness the 5-10 dollar Horrible Freight does over 90% of what I need.... If I were working in the field. (Not a shop) it is likely what I'd take in my tool box... I mean.. if it gets lost stolenm stepped on.. no great loss.

[CA_Traveler]

A small 12V test light with ground wire, bulb and probe is a very useful tool because it's very visual and it puts a small load on the circuit.

A cheap HF voltmeter is adequate for most DC checking

For AC a better insulated voltmeter should be considered, and one that physically holds one probe in plastic tabs is better since only one hand is near the circuit - attach the negative lead first. But truthfully most RVers should not be probing AC except perhaps with a no contact tester.

The 3 light plug in tester is also a useful tool. Consider one that has a GFCI test button.

[ktmrfs]

Thermoguy wrote:
Wow - hate to hear the comments, get the cheapest one you can afford. Remember, the only thing between you and the current you are measuring is the meter. If you buy cheap, you get cheap, which may cost you in the end. Also, it's like a calculator. If 1+1=3 then 4 then 6 then 2, is it reliable? No!!

Get a good meter, spend a few extra bucks. I like the ones that automatically detect AC or DC voltage, same setting, auto ranging. Just put it on voltage and you are good to go. I have both a clamp and DMM, but they both measure the same things, the clamp is just easier for clamping to a wire, like a battery cable.

Make sure it is rated to CAT IV 600 V minimum - this is to protect you from shock. If you plan to use it around the house also you might be measuring 120V AC to 240V AC.

As many have mentioned, Fluke is the gold standard and they are priced accordingly, but Amprobe (Fluke's cheap brand) FLIR, Klein, Ideal all are good quality manufacturers. They are all built in the same factories, but QC is different depending on who's name is on them. Stick to a manufacturer of electrical tools and you won't go wrong.

A non contact voltage tester is also good around 120v - not DC. I use it all the time around the house to make sure the power is off before changing a light fixture, switch, etc. A decent one is $20 or so, you can go cheap, but are you sure it works? I guess you can touch the wire and check.

I'd say CatII or CatIII is more than adequate. CatIV stuff get's expensive. CatIII covers main distribution panels, CatII wall outlets. It isn't just for shock protection, also make sure it doesn't blow up in your face or catch fire if you accidentally short across a battery bank in current mode and try to stuff 500A in the 1A range.



CAT III
Distribution-level mains (usually permanently connected).
Equipment at this level is typically in a fixed industrial
location.
CAT II
Local-level mains (wall sockets). Equipment at this level
includes appliances, portable tools, and similar products.
Equipment is usually cord-connected.
CAT I
Secondary (signal level) or battery operated circuits

Fluke has a really nice unit with detachable current head so you can get it around a cable in a tight place when measuring current.

Also if you happen to have a Klein tool non contact voltage tester around the house, PLEASE check Klein tool website for a recall on many of those units. I have two going back under the recall. Apparently they can indicate no power when power is present.

[3_tons]

I have the Klein 600a AC-DC meter and (though 600a is a bit of overkill), it’s one great meter that should be compared to Fluke…Due to future needs, I hate having to buy tools twice to get the one I end-up needing…

3 tons

[Lwiddis]

I vote for an inexpensive HF unit. That’s what I have.

[enblethen]

At times it would be beneficial to have a clamp on DC amp meter. The one from Home Depot is rated to 400 amp. This one from ebay would serve you well. An inexpensive one will not have DC amerage level that will not handle some of the testing.

[Thermoguy]

Wow - hate to hear the comments, get the cheapest one you can afford. Remember, the only thing between you and the current you are measuring is the meter. If you buy cheap, you get cheap, which may cost you in the end. Also, it's like a calculator. If 1+1=3 then 4 then 6 then 2, is it reliable? No!!

Get a good meter, spend a few extra bucks. I like the ones that automatically detect AC or DC voltage, same setting, auto ranging. Just put it on voltage and you are good to go. I have both a clamp and DMM, but they both measure the same things, the clamp is just easier for clamping to a wire, like a battery cable.

Make sure it is rated to CAT IV 600 V minimum - this is to protect you from shock. If you plan to use it around the house also you might be measuring 120V AC to 240V AC.

As many have mentioned, Fluke is the gold standard and they are priced accordingly, but Amprobe (Fluke's cheap brand) FLIR, Klein, Ideal all are good quality manufacturers. They are all built in the same factories, but QC is different depending on who's name is on them. Stick to a manufacturer of electrical tools and you won't go wrong.

A non contact voltage tester is also good around 120v - not DC. I use it all the time around the house to make sure the power is off before changing a light fixture, switch, etc. A decent one is $20 or so, you can go cheap, but are you sure it works? I guess you can touch the wire and check.

[navigator2346]

EE here. Go with a cheap Harbor Freight meter.Most of your work on an rv will be continuity, either you have it or you don't type trouble shooting. Someone mentioned dropping a cheap meter so buy 2.

[ktmrfs]

even the cheap ones are pretty good now UNTIL you drop it. (which you will). But the mid priced ones from brands like Klein tools are IMHO robust enough with moderate care. For occasional use a very good choice IMHO and available at Lowes, HD etc.

Make sure the meter you get is rated for at least CATII better if CATIII, 600V. If no rating, pass big time. Even with only 12V DC accidental wrong connection can cause big issues with safety (fire etc) with a meter not meeting safety standards. Remember, a 12V battery can supply 300-700A or more in short circuit, you want a meter than won't catch fire if it fails or you hooked it up wrong.

Then there are the Fluke and older Tektronix TX series handheld DMM's. Drop them from 20 ft, no problem, have it on current mode and connect across a 240V line or across a 12V battery bank, no problem, pop in a new fuse, need a unique set of leads, no problem, but you will pay more, but they will be passed on to your grandkids.

[Matt_Colie]

Kansas,

You have a lot of great advice here. Some of us are like BB_TX. I am one of those.

I will guess by the way you asked that you currently have nothing. Let me make some suggestions.

At Hazard Fright, you can get a truly cheap Mutlimeter. That cheap CCV will do 95% of what you can do within your current experience level. Get one of those. (~7$us when not on sale.)

Then go to a storefront car parts place and get a socket with two wire leads (not a tail light base they have two leads for a two filament bulb), and a 12V bulb to fit that socket. If the have plain alligator clips there, get at least 2. Put this together and you have a test light that can clip on. "Does it have power?" can instantly be answered and this is better than a meter because the bulb actually requires that the circuit can supply power.

Those two items will allow you to do most of the diagnosis of what needs in an RV.

Want more? For 120V things a non-contact voltage detector is nice. Cost less than 10$ and you can't get hurt. Just hold it near the wire.

If you think you want more, learn more first. Then we can help you spend a lot more money. A lot more money.

What is with this guy?
Prior becoming a licensed ships engineer, I sailed as electrician. After I retired, I set up a company that did a lot of electrical work on boats. I did a lot of trouble shooting at that.

Behind me is a full Fluke case that is insured for 800$. In the drawer next to me is one of the cheapo Mutli from Harbor freight. It all has its place.

Matt

[path1]

Good question. When faced with the same dilemma I ended up with about a $300 fluke which wasn't a very good decision because I have to get out the instruction booklet every time I use that thing it's so comprehensive/ complicated. If I used it everyday I'm sure I wouldn't have to break out the book, however i know very little about electricity...fluke also has or used to a free online school that's very helpful for about every thing electrical .

[BB_TX]

I am also an EE and spent my career designing and testing solid state and microprocessor based control systems. Company had all the latest gadgets to test all scenarios. What do I use for my testing now that I am retired? Low priced meters from Home Depot and more often than not my “get one free with any purchase” meters from Harbor Freight. That’s all you need. You don’t need expensive meters for an RV. Have never needed to measure current flow when troubleshooting my RV even though one of my meters does have that capability.

[valhalla360]

For starter, a cheap $10-20 unit will be fine.

Checking amperage is far less commo but even the cheap ones will typically do 12v up to around 10amps. The downside is you have to put it in the circuit. The more expensive clamp on meters don't require the wires to be disconnected.

[MNRon]

I’m an EE and have used lots of lab equipment for my job. At home I have a couple of DVMs and even an old analog one with a clamp-on current measurement capability. With that said, easily 80% of the measurements I’ve taken at home or RVing are simple voltage measurements (both AC and DC); the other 19.99% are resistance measurements (usually just looking for continuity); and the last 0.01% are current readings. My recommendation is to get a voltmeter and carry it, if it’s a cheap one it will probably do everything you ever desire; if you buy a nice expensive Fluke you’ll be able to admire it and be proud of it, but RV use probably won’t distinguish between the two.