Previous in Forum: Changing Transformer Usage   Next in Forum: Transformer Details
Close
Close
Close
27 comments
Guru
United States - Member - New Member

Join Date: Mar 2010
Location: In the pool because it is too hot.
Posts: 3053
Good Answers: 140

Digital Multimeter With DC Clamp On

02/10/2012 1:48 AM

Dear fellows,

I consider to buy a multi- meter with DC clamp on system to measure DC current mainly in solar panels. The strings are up to 50 Amps DC. I am just using it for personal testing. Who can refer to one low budget reliable type as out of experience? Thank you for the help. D

__________________
Plenty of room here
Register to Reply
Interested in this topic? By joining CR4 you can "subscribe" to
this discussion and receive notification when new comments are added.

Comments rated to be Good Answers:

These comments received enough positive ratings to make them "good answers".

Comments rated to be "almost" Good Answers:

Check out these comments that don't yet have enough votes to be "official" good answers and, if you agree with them, rate them!
Guru
Technical Fields - Technical Writing - New Member Engineering Fields - Piping Design Engineering - New Member

Join Date: May 2009
Location: Richland, WA, USA
Posts: 21024
Good Answers: 790
#1

Re: Digital multimeter with DC clamp on.

02/10/2012 2:18 AM

How about installing low resistance shunts, measuring voltages across them with a basic multimeter, and calculating the currents?

__________________
In vino veritas; in cervisia carmen; in aqua E. coli.
Register to Reply
Guru
United States - Member - New Member

Join Date: Mar 2010
Location: In the pool because it is too hot.
Posts: 3053
Good Answers: 140
#2
In reply to #1

Re: Digital multimeter with DC clamp on.

02/10/2012 2:53 AM

I installed many panels as a roof, under which I can easily measure.

I hope to bring also the myth down that nothing grows underneath, since our vegetable garden will be there.

The inverters are 400 feet away and 2 conductors of 10 AWG gave me 2.7 Volts voltage drop.

At 20 Amps, 48 Volts DC. I am now using 1/0 because of the distance. These drops are expensive and bring the efficiency down a lot, so do extra series shunts.

With a clamp on device (with Hall effect) I can quickly check the amps per string and also with the solar connectors it is easy to disconnect each panel, short it (since they come with a male and female, minus and plus) by just connecting the + to the minus.

I found one at Sears for $53.99 but do not know if it is good. Extech has one for about $129.00 but I would really have some feedback from users.

There is an ocean between me and Sears and traveling abroad is very expensive. I cannot afford to buy, check it and bring it back (Sears warranty) if I am not happy with it. Extech has more return restrictions.

Probably there are lots more makes, like Fluke (out of budget).

I have a system that uses one pilot inverter to charge batteries (only 300Ah@12 Volts) that can supply 120 volts AC/60 Hz. This pilot becomes the reference for all the grid tie inverters when we have a power failure. So in off grid state, the grid tie inverters become suppliers for everything more than 500 Watts.

This saves thousands for batteries that I do not need. (at night I am messed up off course, but then I usually sleep)

I made strings of 48-100 Volts (the long runs), close to grid parallel 12 Volts 250 Watts circuits and a 375 Watts/12 volts long run for the off grid(battery) inverter.

When everything is finished, I will send a picture.

__________________
Plenty of room here
Register to Reply
Guru
Engineering Fields - Electrical Engineering - Hmmm...

Join Date: Jul 2010
Location: Maryland
Posts: 567
Good Answers: 29
#14
In reply to #2

Re: Digital multimeter with DC clamp on.

02/10/2012 5:00 PM

I bought one at Sears as well. Be careful they have two models, one that does AC only and one that will do AC and DC. They look very similar.

I have yet to use it for anything significant. I tested the DC Amps using a lab supply and a multimeter. It appears to be accurate. At least close to my Fluke. I intend to use it to check my solar array as well, that is, the array that I'm still working on installing.

I read some reviews on the model I bought that weren't positive, but I bought it anyway. We'll see.

Register to Reply Score 1 for Good Answer
Guru

Join Date: Sep 2009
Posts: 1055
Good Answers: 88
#3

Re: Digital multimeter with DC clamp on.

02/10/2012 3:06 AM

Something like UT203 is OK for amateur use. Just don't put it's protection features under test. S.M.

__________________
Life is complex. It has a real part and an imaginary part.
Register to Reply Score 1 for Good Answer
Anonymous Poster #1
#4
In reply to #3

Re: Digital multimeter with DC clamp on.

02/10/2012 3:08 AM

it's its

Register to Reply Score 1 for Off Topic
Anonymous Poster #2
#5
In reply to #4

Re: Digital multimeter with DC clamp on.

02/10/2012 3:16 AM
Register to Reply Score 1 for Off Topic
2
Guru

Join Date: May 2010
Location: in optimism
Posts: 4050
Good Answers: 129
#8
In reply to #5

Re: Digital multimeter with DC clamp on.

02/10/2012 8:04 AM

No maybe

by your site - which is a bit tortuous;

Just don't put it's protection features under test.

expands to;

Just don't put it is protection features under test.

not

Just don't put its protection features under test.

Which is what one presumes you meant - the 'thing' plus possessive 's' = 'the things' protection features. Therefore "it" and possessive = "its"

Does not equal "it is"

__________________
There is no sin except stupidity. (Oscar Wilde, Irish dramatist, novelist, & poet (1854 - 1900))
Register to Reply Good Answer (Score 2)
Guru

Join Date: Sep 2009
Posts: 1055
Good Answers: 88
#13
In reply to #8

Re: Digital multimeter with DC clamp on.

02/10/2012 2:50 PM

English is not my native language as you can tell, but on this I thought it went like: John-John's, It-It's, not "is", not "has". In my language nouns and their pronouns are interchangeable. Thanks. S.M.

__________________
Life is complex. It has a real part and an imaginary part.
Register to Reply
Guru
Technical Fields - Technical Writing - New Member Engineering Fields - Piping Design Engineering - New Member

Join Date: May 2009
Location: Richland, WA, USA
Posts: 21024
Good Answers: 790
#15
In reply to #13

Re: Digital multimeter with DC clamp on.

02/10/2012 5:15 PM

That is one of the quirks of English.

Apostrophes are used for contractions and for possessives of nouns, but not generally for plurals and not for possessives of the personal pronouns.

At first it takes conscious attention to sort this out properly, but with care and experience it can become second nature.

--Editor Crankshaft

__________________
In vino veritas; in cervisia carmen; in aqua E. coli.
Register to Reply
Guru
United States - Member - New Member

Join Date: Mar 2010
Location: In the pool because it is too hot.
Posts: 3053
Good Answers: 140
#6
In reply to #3

Re: Digital multimeter with DC clamp on.

02/10/2012 3:20 AM

Thanks. Any idea of the price? Looks like the circuitry of the Sears (same steps)

__________________
Plenty of room here
Register to Reply
Guru
United States - Member - New Member

Join Date: Mar 2010
Location: In the pool because it is too hot.
Posts: 3053
Good Answers: 140
#7
In reply to #3

Re: Digital multimeter with DC clamp on.

02/10/2012 3:56 AM

Saw it advertised for approx. $35.00.

__________________
Plenty of room here
Register to Reply
Guru
Hobbies - Fishing - Old Salt Hobbies - CNC - New Member United States - US - Statue of Liberty - New Member

Join Date: Mar 2007
Location: Rosedale, Maryland USA
Posts: 5198
Good Answers: 266
#9

Re: Digital Multimeter With DC Clamp On.

02/10/2012 8:54 AM

If you already have a multi-meter you could just get a current transducer for it.

__________________
Life is not a journey to the grave with the intention of arriving in a pretty, pristine body but rather to come sliding in sideways, all used up and exclaiming, "Wow, what a ride!"
Register to Reply
Guru
United States - Member - New Member

Join Date: Mar 2010
Location: In the pool because it is too hot.
Posts: 3053
Good Answers: 140
#10
In reply to #9

Re: Digital Multimeter With DC Clamp On.

02/10/2012 9:56 AM

I have plenty of multi-meters, dating from the age of the "flintstones" up to some modern stuff, but DC current with a clamp is not one of it.

If these transducers are clamp on, I get even a lot more expansion for possibilities and can put several pieces in the system. The outputs I can log or read with a multiplexer (and maybe LabView?)

Thanks.D

__________________
Plenty of room here
Register to Reply
Guru
Hobbies - Fishing - Old Salt Hobbies - CNC - New Member United States - US - Statue of Liberty - New Member

Join Date: Mar 2007
Location: Rosedale, Maryland USA
Posts: 5198
Good Answers: 266
#11
In reply to #10

Re: Digital Multimeter With DC Clamp On.

02/10/2012 10:45 AM

Yes they are clamp on. Many manufactures of multi-meters will make one mine an Amprobe CT-600 will read up to 600 amps AC or DC. You may find that one of the manufactures of the new multi-meters you have make one. Just use the output port from it.

__________________
Life is not a journey to the grave with the intention of arriving in a pretty, pristine body but rather to come sliding in sideways, all used up and exclaiming, "Wow, what a ride!"
Register to Reply Score 1 for Good Answer
Guru

Join Date: Apr 2009
Location: USA, Florida
Posts: 1586
Good Answers: 125
#12

Re: Digital Multimeter With DC Clamp On.

02/10/2012 11:13 AM

Try this cheap little beauty.

__________________
An obstacle is something you see when you take your eyes off the goal.
Register to Reply Score 1 for Good Answer
Guru
United States - Member - New Member

Join Date: Mar 2010
Location: In the pool because it is too hot.
Posts: 3053
Good Answers: 140
#16
In reply to #12

Re: Digital Multimeter With DC Clamp On.

02/10/2012 8:06 PM

This does about what the Sears does also. I guess they both come from Shenzhen.

The UT203 has no temp probe but is $20.00 cheaper. This advertised clamp on meter cost the same what Sears sells it for without promotion. I think I try the Sears because of the service. (warranty) GA, thanks

__________________
Plenty of room here
Register to Reply
Guru

Join Date: May 2006
Location: Placerville, CA (38° 45N, 120° 47'W)
Posts: 6135
Good Answers: 246
#17
In reply to #16

Re: Digital Multimeter With DC Clamp On.

02/11/2012 12:09 AM

Be careful! Some clamp-on meters act as current transformers. These will ONLY measure AC current.

The only ones I know that measure DC current use a Hall sensor.

Unless it specifically says it measures DC current, it probably does not! I saw no mention of DC in the Radio Shack ad.

__________________
Teaching is a great experience, but there is no better teacher than experience.
Register to Reply Score 1 for Good Answer
Guru

Join Date: Apr 2009
Location: USA, Florida
Posts: 1586
Good Answers: 125
#19
In reply to #17

Re: Digital Multimeter With DC Clamp On.

02/11/2012 5:30 AM

Read more carefully. The ad mentions DC current before it mentions AC current in the specification section.

__________________
An obstacle is something you see when you take your eyes off the goal.
Register to Reply
Guru

Join Date: Jun 2011
Location: Phnom Penh
Posts: 4019
Good Answers: 102
#20
In reply to #19

Re: Digital Multimeter With DC Clamp On.

02/11/2012 6:00 AM

I just read the user's manual for that unit and it says it does DCamps, so it must.

Looks good in the picture.....

At that price it's an excellent disposable meter.

__________________
Difficulty is not an obstacle it is merely an attribute.
Register to Reply
Guru

Join Date: May 2006
Location: Placerville, CA (38° 45N, 120° 47'W)
Posts: 6135
Good Answers: 246
#25
In reply to #19

Re: Digital Multimeter With DC Clamp On.

02/11/2012 6:24 PM

Just in case, I was referring to the link of post #12, which points to a Radio shack ad. I still see no mention of DC in the ad. It just says true RMS. The true RMS of DC is zero.

I did look at the manual, and yes, it does measure DC, but there is nothing in the ad that that says so.

__________________
Teaching is a great experience, but there is no better teacher than experience.
Register to Reply
Guru

Join Date: Apr 2009
Location: USA, Florida
Posts: 1586
Good Answers: 125
#26
In reply to #25

Re: Digital Multimeter With DC Clamp On.

02/11/2012 7:08 PM

OK, this is a copy and paste of the third (3rd) bullet down in the "check it out" section of the ad: DC current 40.00A/400.0A/800A; AC current 40.00A/400.0A/800A True RMS

Hint: scroll down a little in the ad.

__________________
An obstacle is something you see when you take your eyes off the goal.
Register to Reply
Guru

Join Date: May 2006
Location: Placerville, CA (38° 45N, 120° 47'W)
Posts: 6135
Good Answers: 246
#27
In reply to #26

Re: Digital Multimeter With DC Clamp On.

02/11/2012 9:12 PM

OK, I stand corrected!

I did scroll down a little, but as soon as I saw:

I assumed I had seen the entire ad. Now that I did scroll down farther, it does indeed look pretty good for the price! To me it sure is a strange layout for the ad...

__________________
Teaching is a great experience, but there is no better teacher than experience.
Register to Reply
Guru

Join Date: Jun 2011
Location: Phnom Penh
Posts: 4019
Good Answers: 102
#18

Re: Digital Multimeter With DC Clamp On.

02/11/2012 1:17 AM

I have 3 DC clamp meters

The Fluke died and will stay that way.

The two that still work....

Lutron CM9940 is a tough unit measures up to 600ADC. Cost approx USD150

Kyoritsu KEW MATE MODEL 2001has a very handy small open head that is easy to slip onto conductors in cramped situations. Measures upto 100ADC. Cost approx USD150.

These instruments earn their keep. New batteries is all they ask for.

Taiwanese instruments and tools have a good price/quality break.

IMO those $50 instruments are too cheap to be "good".

__________________
Difficulty is not an obstacle it is merely an attribute.
Register to Reply
Guru

Join Date: Apr 2009
Location: USA, Florida
Posts: 1586
Good Answers: 125
#21
In reply to #18

Re: Digital Multimeter With DC Clamp On.

02/11/2012 6:02 AM

I have a $300.00 Fluke that measures up to 600ADC and the "cheap" RS model that measures up to 800ADC. Cheap has more functions than Fluke.

Cheap trumps Fluke all day.

I like cheap.

__________________
An obstacle is something you see when you take your eyes off the goal.
Register to Reply
Guru

Join Date: Jun 2011
Location: Phnom Penh
Posts: 4019
Good Answers: 102
#22
In reply to #21

Re: Digital Multimeter With DC Clamp On.

02/11/2012 6:09 AM

You can get a calibration certificate for a Fluke.

If this is not required then I agree. Cheap is good.

That is really cheap. How long has it been satisfying you?

__________________
Difficulty is not an obstacle it is merely an attribute.
Register to Reply
Guru

Join Date: Apr 2009
Location: USA, Florida
Posts: 1586
Good Answers: 125
#23
In reply to #22

Re: Digital Multimeter With DC Clamp On.

02/11/2012 7:55 AM

I've had it over a year and have had no issues.

But I haven't dropped it yet either.

__________________
An obstacle is something you see when you take your eyes off the goal.
Register to Reply
Guru

Join Date: Jun 2011
Location: Phnom Penh
Posts: 4019
Good Answers: 102
#24
In reply to #23

Re: Digital Multimeter With DC Clamp On.

02/11/2012 10:25 AM

So long as it's not made from recycled VHS video cassette cases (like the stuff inside Korean cars) it should be right.

__________________
Difficulty is not an obstacle it is merely an attribute.
Register to Reply
Register to Reply 27 comments
Interested in this topic? By joining CR4 you can "subscribe" to
this discussion and receive notification when new comments are added.

Comments rated to be Good Answers:

These comments received enough positive ratings to make them "good answers".

Comments rated to be "almost" Good Answers:

Check out these comments that don't yet have enough votes to be "official" good answers and, if you agree with them, rate them!
Copy to Clipboard

Users who posted comments:

34point5 (1); Anonymous Poster (2); dkwarner (3); dvmdsc (5); Lo_Volt (1); ozzb (2); SimpleMind (2); Tornado (2); Wal (4); WJMFIRE (5)

Previous in Forum: Changing Transformer Usage   Next in Forum: Transformer Details

Advertisement