DC clamp-on

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GoldDigger

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Retired PV System Designer
I'm looking for a DC clamp-on probe. 100A to 1V output. Any suggestions?

ice

Since a DC clamp can only work with something like a Hall Effect sensor, it would have to have its own battery power or take power from the meter it is attached to. I have not looked really hard, but I had only seen DC clamps that were integrated with a meter.
There are standalone probes with power supplies from sites like this but I have no idea what the prices are or what sort of voltage they output or what impedance is required at the voltmeter input. The ones designed for use with oscilloscopes probably were built with an input impedance of 1 megohm or more in mind.
 

SG-1

Senior Member
A Fluke 90i-610s AC/DC Current Probe produces 10mV/A on the 100A scale. That is 1000mV or 1V/100A

That model is for a scope, but it came with an adapter so it can also plug into a meter.
 

gar

Senior Member
Location
Ann Arbor, Michigan
Occupation
EE
130413-0849 EDT

I have a Fluke Y8100. Not made anymore.

Two ranges 0-20 A and 0-200 A. 2 V out at full scale into a load greater than 3k. Frequency DC to 1 kHz. Prolonged operation above 200 A or 1 kHz can cause damage. Not a very clear definition of the limation. Max voltage 600 V DC or 480 V AC. Connection to display device, scope or meter, is a cable with dual banana plugs at both ends on 3/4" centers. Aperture size 3/4" dia. Only has a one turn pot for zero adjustment. Ten turn would be much better.

Accuracy is in the +/-2,3,6 % range.

Uses four AA cells.

AC output noise on 20 A range is about 2 mV with no filtering and a moderately low magnetic field noise level. In DC mode, meaning switch the indicating meter to DC, you can see the effect of the earth's magnetic field.

.
 

gar

Senior Member
Location
Ann Arbor, Michigan
Occupation
EE
130413-0937 EDT

limation should have been limitation.

iceworm:

What is your need? Accuracy, bandwidth, aperture, monitoring waveform, insulation, etc.?

.
 

iceworm

Curmudgeon still using printed IEEE Color Books
Location
North of the 65 parallel
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... What is your need? Accuracy, bandwidth, aperture, monitoring waveform, insulation, etc.?

Answered in order
Just want - not need.
2% would be good

Bandwidth? uhhhhh.... It's dc. Okay - I suspect you are asking if I need to track a 200MHz analog data stream - No. Say more like an IGBT chopper for an electric car - say 4KHZ. That's not my application - but like that

Aperture? Like the hole for the wire? or a math concept like synthetic aperture? If you mean the hole - 3/4" min, 1" max give or take a bit or two or more or less

monitoring wave form - I don't know. I think that may be one of the reasons I want the probe

insulation - 600V is okay

gar - now that you have this information, do you have any suggestions -- -- for current production models preferably

ice
 

iceworm

Curmudgeon still using printed IEEE Color Books
Location
North of the 65 parallel
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EE (Field - as little design as possible)
SG, templdl -
thanks. The fluke 90i is an option.

gold -
a clamp-on meter is an option - not the best but would work. Any suggestions on moderately priced models?

ice
 

fmtjfw

Senior Member
Fluke i410

Fluke i410

I have one:

0.5--400A AC/DC range
3.5% + 0.5A accuracy
DC--3kZ bandwidth
1mV/A output
CAT III -- 600V
30mm or 2 x25mm aperature
std 9V battery
 

gar

Senior Member
Location
Ann Arbor, Michigan
Occupation
EE
130413-1301 EDT

iceworm:

Go to this site and look around http://www.gmw.com/electric_current/LEM/hall-transducers.html

They make three types of transducers, I believe.

1. The raw Hall device.
2. An analog unbalanced open loop type. Magnetic core plus the Hall device.
3. And a closed loop type where the signal magnetic field is balanced by an opposing generated magnetic field so that the Hall device is is a null balance detector. Their highest accuracy.

Aperture is the hole in the sensor. A DC signal with a variation is going to require a system with adequate low pass bandwidth to pass the signal variations. If you want to look at the switched output of IGBT, then you will require considerable bandwidth.

.
 

MarineTech

Member
Location
Camarillo, CA
Since a DC clamp can only work with something like a Hall Effect sensor, it would have to have its own battery power or take power from the meter it is attached to. I have not looked really hard, but I had only seen DC clamps that were integrated with a meter.
There are standalone probes with power supplies from sites like this but I have no idea what the prices are or what sort of voltage they output or what impedance is required at the voltmeter input. The ones designed for use with oscilloscopes probably were built with an input impedance of 1 megohm or more in mind.

GoldDigger yes 100%.

I use a Fluke i310s AC/DC Current Clamp (Hall Effect Technology for conductors up to 3/4" diameter) as a companion to my Scopemeter for analyzing complex current waveforms. Bandwidth to 20kHz (3 dB down). Works great for analyzing inverters, HVAC, switch mode power supplies, industrial controllers, Marine and Automotive electrical diagnostics. (30A or 300A AC rms) or (+/- 45A or +/- 450A DC).

For large DC currents without complex waveform analysis(basically only inrush) I use my Fluke 381 AC/DC clamp meter. DC current to 999.9A.
 

ramsy

Roger Ruhle dba NoFixNoPay
Location
LA basin, CA
Occupation
Service Electrician 2020 NEC

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iceworm

Curmudgeon still using printed IEEE Color Books
Location
North of the 65 parallel
Occupation
EE (Field - as little design as possible)
Thanks guys. The i310 and i410 are interesting.

Has anyone used any of the extec such as a CA250?

ice
 

iceworm

Curmudgeon still using printed IEEE Color Books
Location
North of the 65 parallel
Occupation
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Thanks for the comments. I was hoping someone had used any of the extech line. I can borrow a tek A622 - and likely will. 100A peak, 10mv/A or 100mv/A. If they weren't $600 I get one.

I have never understood the need for these clamps that plug into a DMM.

They cost more than a stand-alone clamp meter. Why not just get one of those???

A probe can be hooked to a scope or a recorder as well as a DVM. I'd like to be able to do that if I can for some testing.

ice
 

SG-1

Senior Member
I have used a Fluke 80i ( plug in type ) to track ground fault current in milli-ampere range. One can turn the DMM to the micro-ampere range to get a reading that can be tracked to the fault. The normal clamp meters cannot see current in this range. Works very well inside switchgear.
 

iceworm

Curmudgeon still using printed IEEE Color Books
Location
North of the 65 parallel
Occupation
EE (Field - as little design as possible)
I have used a Fluke 80i ( plug in type ) to track ground fault current in milli-ampere range. One can turn the DMM to the micro-ampere range to get a reading that can be tracked to the fault. The normal clamp meters cannot see current in this range. Works very well inside switchgear.

Which one? 110?, 410?, 1010? I have not seen any accuracy specs on the 1010

ice
 

ELA

Senior Member
Occupation
Electrical Test Engineer
Thanks for the comments. I was hoping someone had used any of the extech line. I can borrow a tek A622 - and likely will. 100A peak, 10mv/A or 100mv/A. If they weren't $600 I get one.



A probe can be hooked to a scope or a recorder as well as a DVM. I'd like to be able to do that if I can for some testing.

ice
That would be great choice if you can borrow it.
I use an aemc sl261 that has similar specs and it has been great meter for my uses.
When looking at complex waveforms having a higher bandwidth is important.
 
Last edited:

MarineTech

Member
Location
Camarillo, CA
I have used a Fluke 80i ( plug in type ) to track ground fault current in milli-ampere range. One can turn the DMM to the micro-ampere range to get a reading that can be tracked to the fault. The normal clamp meters cannot see current in this range. Works very well inside switchgear.

For 60 Hz AC Leakage (small ground faults like insulation breakdown) I use a Hioki 3283 Clamp on Leak HiTester.

Best regards,

MarineTech
 
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