 Notice. New forum software under development. It's going to miss a few functions and look a bit ugly for a while, but I'm working on it full time now as the old forum was too unstable. Couple days, all good. If you notice any issues, please contact me. |
Forum Index : Electronics : T&E vs HD Flex CSA question....
| Author | Message | ||||
Grogster Admin Group  Joined: 31/12/2012 Location: New ZealandPosts: 9308 |
In all my dealings with cables of all types over the years, the mm specification always refers to the CSA(cross-sectional area) of the copper core of each conductor. Therefore, 2.5 T&E, typically used for all three-pin outlets for house and building wiring, means the copper is an average of 2.5mm CSA for each core. IE: The 2.5mm reference DOES NOT refer to the overall thickness of the wire, INCLUDING the insulation. The same can be applied to just about any wire I have ever come across. 0.75mm speaker wire, means that the conductors are 0.75mm thick. 1mm T&E used for lighting circuits, means the copper conductor inside each wire is 1mm thick. I write all this, so you can help me understand where I am going wrong with HD flex cable. I asked for 6mm single-phase HD flex for connecting to a semi-industrial 240v generator, and they sent me cable that is marked as 3x6.0 along it's sheath, but the copper inside each core is only 3mm thick. The generator is 6600W output, single phase. I was wanting to use 6mm cable, thinking I would get 6mm copper in each core, as I wanted to minimize voltage-drop at maximum output over 15 meters or so of cable. I could have got 4mm, but 6mm was recommended, and I agreed with that reasoning, and was prepared to pay the extra price for what I thought would be a thicker copper content. The cores WITH the insulation, measure 6mm exactly. This is very odd, and against every other cable I have ever dealt with or have ordered before in my career. Even bog-standard domestic extension cords are referenced as 1mm or 1.5mm for the HD yellow ones(15 amp). This is the first time I have ordered HD flex though, so can anyone enlighten me as to if there is a different AUS/NZ standard for grading HD flex? I will contact the supplier next week, but would love for anyone with suitable knowledge of cables, to chime in here and offer their 2c. Thanks. Smoke makes things work. When the smoke gets out, it stops! |
||||
yahoo2 Guru  Joined: 05/04/2011 Location: AustraliaPosts: 1166 |
Sounds like you have pretty much answered your own question Grogster, CSA is mm squared not diameter mm. it all looks the same at small sizes. Wire - Convert from Square mm to Diameter mm the only trade that talks in total wire diameter (including insulation) are the automotive guys I'm confused, no wait... maybe I'm not... |
||||
| Grogster Admin Group Joined: 31/12/2012 Location: New ZealandPosts: 9308 |
Thanks for that - I was just a little confused. Looks like they HAVE sent the correct cable. As you say - all looks about right with thinner cables, I guess, but just as with the large capacity hard-drives, you start to see a difference as the size goes up. It's all in the mathematics, I guess! 
Thanks again for the reply, and also the link - very helpful.  Smoke makes things work. When the smoke gets out, it stops! |
||||
| Pete Locke Senior Member  Joined: 26/06/2013 Location: New ZealandPosts: 181 |
Yes. Flex cable as opposed to good ol' TPS always looks thinner due to the extra strands. Know what you mean though. How can that thin multi strand cable do the same job :-) |
||||
| Grogster Admin Group Joined: 31/12/2012 Location: New ZealandPosts: 9308 |
It is VERY thick flex, compared to standard 10-amp extension-cord lead, so it sure LOOKS the part, but once I stripped the sheath and got to the actual copper wire, it just did not look right to me!
Big thick juicy cables are not really something I deal with every day, although, I do have the knowledge and experience to correctly terminate them - I just thought that it would be thicker. 
6600W is 28-amps or so(full load, including surge), and 6000W standard output(26-amps continuous), so we should be OK. I got 15 meters of cable, but that was allowing for extra. I expect it will be down to 12 meters or so by the time it is actually installed, so that will make a difference again. I always believed that it is better to have more copper then the numbers say you actually need, for some reserve capacity and to allow for voltage-drop under load. Thanks for your comment. Smoke makes things work. When the smoke gets out, it stops! |
||||
| Pete Locke Senior Member Joined: 26/06/2013 Location: New ZealandPosts: 181 |
Oh yes. A mate of mine put in a small system for off grid in his new place. Back country controller thing. Also has a water wheel (which was my first post on this forum) and wanted decent cable to hook it all up. As luck would have it, we replaced a whole lot of 16mm flex at work used for an electric heater bank. Damn thing caught fire (almost) and charred the first meter or so of cable. So all new cable for that. He made use of the wast for his set up. With a measured current of 17amps from memory, it dropped .00000000naff all volts over the 3 meter lengths in use. There's no substitute for diameter. Even with electrickery |
||||
| Grogster Admin Group Joined: 31/12/2012 Location: New ZealandPosts: 9308 |
Electrickery 
Love that. Thank you for your posts - it has put my mind at ease that this is the correct cable for the job. Smoke makes things work. When the smoke gets out, it stops! |
||||
 Print this page |
