wire ratings

[MitchK]

I'm putting KT88s in my 5150, but the tube sockets are too close together so I built a little platform for them to be on, mounted the sockets on that and now I'm going to run wire from those into the chassis where they can connect to the original PCB. What occurred to me though was that some of these wires will have almost 500V running through them and not all wires are going to handle that. I was going to hook them up with speaker wire but I don't know the rating of it. it is really good quality speaker wire though, solid pieces of wire not stranded, but they are kind of thin a bit less than 1 mm. cost me 3$ a foot! but its all I have and I want to hook this stuff up tonight.

so I guess what I'm asking is, will they catch on fire?

[Enzo]

The qualities that make wire "good" for speakers have nothing to do with what you need for high voltage low current runs for the tubes.

Wire comes in current handling capability - they make charts - for when you run high current power down a length of it. Example being a 50 foot speaker cable. But the wire is usually rated in voltage.

But your wires won't catch fire. You need to worry about their voltage rating - how much voltage difference can there be between the conductor inside and something on the outside before an arc will puncture the insulation and short things out. If you have 500v on a wire and the insulated wire is laying on the chassis, then the insulation better have at least a 500v rating, or it might punch through. 600v wire is easy enough to find.

[MitchK]

So its the insulation that matters not the gauge of the wire etc? These wires are all coated in PVC, but I have no idea what it is rated for. once again its speaker wire, high quality speaker wire, but none the less not meant to have 500V running through it. I've already hooked it all up am I running the risk of an arc like that should I take it off and find some better wire? most stuff doesn't have the rating labeled on it so I'm just not sure what to look for.

thanks enzo I know this is a pretty boring question haha.

[Enzo]

Air is a pretty good insulator too, so if the wire is not leaning on the chassis, then a lower voltage insulating jacket will work. Of course if you grab the wire and YOU are grounded...

Speaker wire tends to be heavy, after all the power to the speaker is relatively low voltage and high current. That is opposite what tubes need. Even at 500 volts, 100 watts only means 200 milliamps is flowing, and that is 2/10 of an amp. SO heavy wire does nothing for you inside the amp except to get in the way.

[unclejed613c]

most off the shelf hookup wire is rated at either 300v or 600v.
i use teflon insulated wire for most repairs, rated at 600v.for anything higher, your best bet is to scavenge focus grid wire from TV flybacks, which is rated at 5kv, or pix tube anode wire (again scavenged from flyback xfmrs) which is usually rated at 50 or 60kv.