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I need (inexpensive) 6 conductor wire
- Thread starter lesrhorer
- Start date
Hi @lesrhorer
Mark has given you a good reference. Which should work for most applications. Good luck.
However, in your posting you say "any significant current". So what is the worst case current load? Milli Amps, 100s of milli Amps? An Amp or two? What are these signal wires going to? Motors? (Amps), Relays? . It is a puzzle due to the fact that the voltage is so high.
But both voltage and current is important when putting two wires next to each other. This may determines the temperature rise of the wire and hence the insulation required. (Or maybe other aspects of the installation determines the operating temperature.) Insulation material properties degrade rapidly with elevated temperature. The insulation materials fail due to high electrical fields between two adjacent wires (or a wire to ground), which means the voltage per insulation thickness (spacing between the two potential points). When you put the wires inside a case the air cannot cool the wire as much. 600VDC vs 300VDC of the same insulation material implies that the spacing between the two conductors is larger, sometimes because they use a thicker insulation. (Because the wires are round one must do calculations in cylindrical coordinates to determine the field strength, but lets not bother with that!)
Illustration:
My old house was originally wired with knob and tube (1930s). This was actually very good wiring, but limited. The 14 gauge wires are simply copper with some old tar and clothe wrapped around it. But no two wires are ever next to each other except at an outlet or light fixture etc. So the space between wires is always inches and so the insulation is really the air. Most of the circuits were fused at 30Amp. If the wiring had been modern 14 gauge Romex it would have only been rated and fused/breaker for 15Amp. So the old wire would get hot, but touches nothing. Where it is near wood it has a ceramic knob to hold it a couple of inches away from the wood or if it needs to be put through a board there is a ceramic tube. It is stretched tight so that the wire never droops to touch anything. There was nothing wrong with this wiring except that it had been around a long time. Every joint was soldered and wrapped it rubber tape. However, some Knob and Tube wiring jobs just twist the wires together and can come loose and so it gets a bad name with the insurance companies. In my case, my insurer said they would not insure the house with the Knob and Tube circuits. I took the knob and tube out, along with all of the other "upgrades" that had been done over the 90+ years and replaced all with modern wire .... which has its own issues.
PS. Stranded wire is usually better around machines, especially if there is mechanical flexing. Copper work hardens with flexing or vibrations and then can break. If an individual strand breaks it the current is going to continue via the other strands around the break.
Mark has given you a good reference. Which should work for most applications. Good luck.
However, in your posting you say "any significant current". So what is the worst case current load? Milli Amps, 100s of milli Amps? An Amp or two? What are these signal wires going to? Motors? (Amps), Relays? . It is a puzzle due to the fact that the voltage is so high.
But both voltage and current is important when putting two wires next to each other. This may determines the temperature rise of the wire and hence the insulation required. (Or maybe other aspects of the installation determines the operating temperature.) Insulation material properties degrade rapidly with elevated temperature. The insulation materials fail due to high electrical fields between two adjacent wires (or a wire to ground), which means the voltage per insulation thickness (spacing between the two potential points). When you put the wires inside a case the air cannot cool the wire as much. 600VDC vs 300VDC of the same insulation material implies that the spacing between the two conductors is larger, sometimes because they use a thicker insulation. (Because the wires are round one must do calculations in cylindrical coordinates to determine the field strength, but lets not bother with that!)
Illustration:
My old house was originally wired with knob and tube (1930s). This was actually very good wiring, but limited. The 14 gauge wires are simply copper with some old tar and clothe wrapped around it. But no two wires are ever next to each other except at an outlet or light fixture etc. So the space between wires is always inches and so the insulation is really the air. Most of the circuits were fused at 30Amp. If the wiring had been modern 14 gauge Romex it would have only been rated and fused/breaker for 15Amp. So the old wire would get hot, but touches nothing. Where it is near wood it has a ceramic knob to hold it a couple of inches away from the wood or if it needs to be put through a board there is a ceramic tube. It is stretched tight so that the wire never droops to touch anything. There was nothing wrong with this wiring except that it had been around a long time. Every joint was soldered and wrapped it rubber tape. However, some Knob and Tube wiring jobs just twist the wires together and can come loose and so it gets a bad name with the insurance companies. In my case, my insurer said they would not insure the house with the Knob and Tube circuits. I took the knob and tube out, along with all of the other "upgrades" that had been done over the 90+ years and replaced all with modern wire .... which has its own issues.
PS. Stranded wire is usually better around machines, especially if there is mechanical flexing. Copper work hardens with flexing or vibrations and then can break. If an individual strand breaks it the current is going to continue via the other strands around the break.
- Joined
- Dec 18, 2022
- Messages
- 2,741
How about selecting the size wire you require in single strands then after you run them wrap them with spiral wire loom wrap which come in numerous sizes? it will make adding additional strands and replacing individual strands easier...
- Joined
- Apr 29, 2019
- Messages
- 2,279
As good as I can explain in layman's terms.......
When talking about AC voltage the listed voltage is the average voltage.
With AC the voltage starts at 0V and rises to a value greater than the rated voltage, so that the average comes out to the rated voltage.
In this case it is 230V AC. that means the peak voltage will be 325.3 volts. This would exceed the rating of the 300V wire. Everything in the system must be rated to handle more than the 325.2V. It is bad practice to design real close to the design limits, you always want some safety factor.
To get the peak voltage you multiply the rated voltage by the square root of 2 (1.414)
I am well aware. I am not sure I have the room. The pathway is pretty tight. That. and of course doubling up on the color code - especially with 230V - is not exactly ideal.
Exactly, and 325V is not merely close to 300V, it is higher. Add in surges, and the voltage on a 230VAC line can readily exceed 400V from time to time, and 230VAC is nothing to play around with.
Thanks!A 6 conductor is not common, either 5 or 7. The key word is 600V rating, and although this may be control wiring the gauge should be in accordance with the fuse rating for the wiring, as a short circuit could cause the wire/insulation to go up in smoke very quickly. Automation direct has 20AWG and 22AWG on 600/1000V rating at around a $1-2/foot, 20'minimum. Free shipping on orders over $50. Ebay listing below is for 10' 600V for $14 shipped.
SAB 02042007 20 AWG 7C Flexible PVC Control Cable LOT OF 10' FOOT | eBay
If you are not able to pick up locally, we are able to get competitive freight quotes as well.www.ebay.com
It is usually rated for 300V. Certainly all that I have is. Playing pattycakes with insulation rating is bad enough, but doing so with tightly twisted pairs... No, thank you.
600V ribbon cable?
It isn't, and yes, it is an unusual case.
