A simple wire question

[G-Sun]

Is this wire ok for hook-up:
ALPHA WIRE - 6713 RD005 - WIRE, ECO, 22AWG, RED, 30.5M
http://no.farnell.com/jsp/search/productdetail.jsp?sku=1764934

Can I use it for 220V connections as well? (rated 600V, so should be ok I guess)

 

[Moose]

That's good wire for general use, but you have to be careful on current as well as voltage when choosing wire.

Here's a good chart with current per AWG size to let you know what's safe for what:

http://www.powerstream.com/Wire_Size.htm

Thought I might inquire a bit about choosing wire sizes to see what others think. If anyone thinks I'm making bad choices, point it out so I learn!  I tend to choose something double the chassis current rating (and then some for anything) as my minimum gauge.

22 ga should be good for most tasks, though I find it gets a little thick for some tasks, like crimp headers , where I use a 26 or 24 AWG 300V, which is thinner due to the thinner jacket.

So, for example, I use MOSTLY 24AWG 600V in my guitar pedals, though sometime I use 26AWG and never worry about it at all. 9V at 15mA is NOTHING for current.

For the mic pre I just built, I used 300V for the power run because I had to daisy chain headers and anything fatter wouldn't fit the molex header. +/-16V doesn't take much insulation.

For tube amps I always use 600V for everything. Much of it solid core. I use 20 or 22 AWG for mains, 22AWG for heaters, but sometimes use 24awg for signals or preamp tube heaters with lower current draw because it's easier to stick two solid core wires through the socket hole or an eyelet on a pot.

 

[G-Sun]

That's good wire for general use, but you have to be careful on current as well as voltage when choosing wire.

Here's a good chart with current per AWG size to let you know what's safe for what:

http://www.powerstream.com/Wire_Size.htm

Thought I might inquire a bit about choosing wire sizes to see what others think. If anyone thinks I'm making bad choices, point it out so I learn!  I tend to choose something double the chassis current rating (and then some for anything) as my minimum gauge.

22 ga should be good for most tasks, though I find it gets a little thick for some tasks, like crimp headers , where I use a 26 or 24 AWG 300V, which is thinner due to the thinner jacket.

So, for example, I use MOSTLY 24AWG 600V in my guitar pedals, though sometime I use 26AWG and never worry about it at all. 9V at 15mA is NOTHING for current.

For the mic pre I just built, I used 300V for the power run because I had to daisy chain headers and anything fatter wouldn't fit the molex header. +/-16V doesn't take much insulation.

For tube amps I always use 600V for everything. Much of it solid core. I use 20 or 22 AWG for mains, 22AWG for heaters, but sometimes use 24awg for signals or preamp tube heaters with lower current draw because it's easier to stick two solid core wires through the socket hole or an eyelet on a pot.

Thanks a lot!
Yes, Molex is a big consideration. I'll need something that fits for Molex.
So , bigger AWG is smaler wire?
How do I know what wire suits what current?
Do I have to look at the actual picture to see how well insulated it is?

And PSU-Molex.. Is that something on it's own, taking larger wire, or?

I'm to place my first order on Farnell. What should I buy for basic stuff?

(Sorry, many questions )

 

[Meathands]

So , bigger AWG is smaler wire?

Yup.

How do I know what wire suits what current?

See the link in Moose's post.

And PSU-Molex.. Is that something on it's own, taking larger wire, or?

Look at the datasheet for the Molex that fits your PCB. It should tell you how thick of wire it can take.

I'm to place my first order on Farnell. What should I buy for basic stuff?

22-24 is good multi-purpose signal wire. You might want to get some 18AWG, too, for stuff that's carrying more current.

 

[G-Sun]

22-24 is good multi-purpose signal wire. You might want to get some 18AWG, too, for stuff that's carrying more current.

Thanks! I'll go for some 18 gauge and 24 gauge then

 

[0dbfs]

Yes. Some really small stuff is usefull too and can help with dressing and tidiness. I always have a ton of cat5 scraps that I use. 8 different colors. Small. Almost free.

In my recent tube mic build I had ordered tube mic cable so I used maybe a foot of that per mic to wire up the PSU and mic. If it works in the cable it should be fine in the PSU and mic and all colors match.

Cheers,
Jb

 

[G-Sun]

Yes. Some really small stuff is usefull too and can help with dressing and tidiness. I always have a ton of cat5 scraps that I use. 8 different colors. Small. Almost free.

Cat5 Sounds tidy. Have to check current for those.

In my recent tube mic build I had ordered tube mic cable so I used maybe a foot of that per mic to wire up the PSU and mic. If it works in the cable it should be fine in the PSU and mic and all colors match.

So, special cable for tubes?
Thanks!

 

[0dbfs]

This is the stuff I used:
http://www.redco.com/shopexd.asp?id=706

It's seven conductor. Two of the conductors are larger AWG so I used those for heater circuit (red) and the Blue as the GND path back to the PSU. I just cut a foot or so of scrap off the 30' length and used the pieces to wire up both the mic internals and the PSU internals keeping the color scheme consistent with how i wired those signals n the cable.

Without knowing exact specifics of "the required spec" I reasoned that if all those signals are traveling through 30' of this stuff then 6-12" more is going to be fine. And it has been so far.

If you google the cat5 spec (i think it's on wikipedia) you can determine the current and voltage rating that cat5 cable conductors must have at a minimum. Voltage ratings or current ratings alone don't tell the whole story though do they? I mean we are talking about the cable/conductor's ability to transfer a certain amount of current at a certain voltage without melting... So, 600V tells us not much while 600V / 1A tells us a little more. Determining the resistance of the conductor (surely it's not 0.000000 ohms) will allow us to see how much power it dissipates with a given V&I and perhaps the point at which the conductor will fail. Sort of like a very low value resistor with a specific wattage rating.

Cheers,
jonathan

 

[Moose]

So, special cable for tubes?
Thanks!

Not for tubes in general. For tube mics.

A normal mic cable is just 3 pin XLR -- all it takes is the signal and all it ever sends is phantom power.

A TUBE mic has to power the heater filament in the tube, etc... So you have conductors for the normal XLR, plus extra for B+, heaters, etc...  Jonathon was pointing out that you can use the scraps from the mic cable inside your power supply so that everything matches nicely. Pretty smart way to make your troubleshooting easier and make a tidy build I bet!

For tubes in general, like amplifiers or tube based compressors and the like, you do have to be careful of a couple of things. First, a lot of tube use more than 300V, so 600V wire becomes important.  Second, heaters tend to draw a lot more current, especially for power tubes, than signal or B+ so you should drop to 22AWG, or beefier, for octals, for them, though you can probably still run the signal through the same 24AWG or smaller without any problems.

Actually, for all that typing, I just said the same thing I did earlier. Look at your voltage and current and make sure you're over.  It really is that simple!

 

[G-Sun]

Thanks!
Yes, tube mic cable.. I see