Solid vs stranded wire for clamp current probing?  - Page 1
Forum section: electronics / general

author: Jim from Chicago
author_rank: Regular Contributor
timestamp: June 30, 2024, 02:49:46 am
content: Is there a significant difference between using solid vs stranded wire for a current probe measurement? Is solid preferable?

author: Phil1977
author_rank: Frequent Contributor
timestamp: June 30, 2024, 12:35:16 pm
content: It definitely doesn't matter.The electromagnetic induction law only cares about the total current that is sent through a loop confined by the clamp of the meter. It does not matter where in the loop the current flows, nor if it´s in a single wire or distributed over a set of wires.You can even wind the wire you measure for a few times through the clamp. Then the displayed current is multiplied by the numbers of windings. You can use this to increase sensitivity for small currents.(Disclaimer: Very pedantic persons could argue there may be near field effects/capacitive couplings from the test wire to the current clamp that proof my generic statement to be wrong. But these effects are small and usually in the tolerance range of the clamp meter.)

author: Faringdon
author_rank: Super Contributor
timestamp: July 01, 2024, 05:44:31 am
content: i am sure you realise that the skin effect will come into play for hi freq currents...this may overheat the wire and it may desolder it, etc

author: Siwastaja
author_rank: Super Contributor
timestamp: July 01, 2024, 06:01:01 am
content: Quote from: Faringdon on July 01, 2024, 05:44:31 amYou have to remember there is no significant difference between solid and stranded wire in regards of skin/proximity effects. If you need lower equivalent AC resistance, you needinsulatedstrands.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: July 01, 2024, 02:36:03 pm
content: Quote from: Siwastaja on July 01, 2024, 06:01:01 amI mean, "significant" is in the eye of the beholder, but it can be in the 5-20% range. Not exactly useful, but interesting that it happens.Tim

author: HannoB
author_rank: Contributor
timestamp: July 02, 2024, 06:58:54 pm
content: I want to ensure I'm understanding the question correctlyAre you asking whether a current clamp's accuracy depends on whether a solid core vs a stranded cable is being measured (ie. the CT is clamped around a stranded cable)ORAre you asking whether it matters using a solid core vs a stranded cable on the output of the secondary of the Current Transformer?Are you even reffering to a CT?Edit: I see you never mentioned "clamp" or "CT" - it crept in as an assumption along the thread.

author: Phil1977
author_rank: Frequent Contributor
timestamp: July 02, 2024, 08:05:09 pm
content: It was mentioned in the title...

author: Geoff-AU
author_rank: Frequent Contributor
timestamp: July 03, 2024, 11:12:53 pm
content: if you're moving the probe around at all, stranded wire will last a lot longer without breaking

author: T3sl4co1l
author_rank: Super Contributor
timestamp: July 04, 2024, 08:07:15 am
content: I don't even know if the thing being measured is stranded, the coil (current transformer?) is, or just the leads to it...Tim

author: Phil1977
author_rank: Frequent Contributor
timestamp: July 04, 2024, 08:34:13 am
content: And the really nice thing about physics is sometimes you don't need to know...

author: Roehrenonkel
author_rank: Frequent Contributor
timestamp: July 04, 2024, 04:09:54 pm
content: Hi Jim,Quote from: Jim from Chicago on June 30, 2024, 02:49:46 amYes IMHO.But as lomg as it's centered all is good.Some time ago i read in a LEM-app-note: Fill the whole hole with a solid conductor. If not possible: center it.Good luck