FAQ - High voltage wire and wiring.
Posted: Sun Jul 31, 2016 5:19 pm
Seems this subject never had it's own FAQ. Here goes.
Really good high voltage wire rated above 20 kv is a great rarity. The best general substitute on the cheap is special neon sign, high tension wire. However the best is the snow white silicone wire which is traditionally very expensive. I found an ugly, fat, x-ray cable on the ground at a hamfest and it was rated at 100kv. This 1 inch diameter hog cable cost me $4.00 for a 20 foot length.
For fusor work, the current handling capacity of any properly rated high voltage wire or cable is a complete non-issue. In short, any properly rated HV wire you will ever obtain will carry all the current needed to do nuclear fusion in your fusor!
You will all notice, I use white, 30kv silicone wire on fusor IV. It easily handles 40kv plus, naked in air. To get the single length of this wire from my modified X-ray supply, I ran it in 1" diameter white PVC plumbing pipe. (seen in all imiages of fusor IV). The last foot or so drops, in air, to the fusor's top terminal.
The key to 25kv and higher HV wiring of a supply and all metering is to never expose any HV component within the supply to air! keep everything under oil with good clearances.
Leave the oil filled supply with a single length of proper HV rated silicone wire to the HV terminal on the fusor.
The rules for ultra-safe power supply construction and connection:
1. Keep every HV component in the supply under oil.
2. Keep all HV metering resistors under oil as well. Only the low voltage leads from the divider need to exit the oil.
3. Never, ever attempt to splice any HV cable in air.
4. Use only a single continuous, properly rated HV wire or cable from the supply's output insulator to the fusor's HV terminal.
5. It is wise to run such wire in a grounded conduit, if metal, or, better still, plastic pipe to avoid arcing as the cable runs to the fusor. (double insulation)
6. All air connections should have a toroid, ball or other regularly cleaned voltage stress distribution item at the air joint.
7. Any sharp metallic point in an air connection should be totally engulfed in a heavy wad of high voltage silicone putty.
The above applies to any home brew supply at or over 30kv.
Few here have the materials or know-how to manufacture their own suitable fusor HV supply over 30kv. But all will need to run a high voltage cable from their supply to the fusor.
Richard Hull
Really good high voltage wire rated above 20 kv is a great rarity. The best general substitute on the cheap is special neon sign, high tension wire. However the best is the snow white silicone wire which is traditionally very expensive. I found an ugly, fat, x-ray cable on the ground at a hamfest and it was rated at 100kv. This 1 inch diameter hog cable cost me $4.00 for a 20 foot length.
For fusor work, the current handling capacity of any properly rated high voltage wire or cable is a complete non-issue. In short, any properly rated HV wire you will ever obtain will carry all the current needed to do nuclear fusion in your fusor!
You will all notice, I use white, 30kv silicone wire on fusor IV. It easily handles 40kv plus, naked in air. To get the single length of this wire from my modified X-ray supply, I ran it in 1" diameter white PVC plumbing pipe. (seen in all imiages of fusor IV). The last foot or so drops, in air, to the fusor's top terminal.
The key to 25kv and higher HV wiring of a supply and all metering is to never expose any HV component within the supply to air! keep everything under oil with good clearances.
Leave the oil filled supply with a single length of proper HV rated silicone wire to the HV terminal on the fusor.
The rules for ultra-safe power supply construction and connection:
1. Keep every HV component in the supply under oil.
2. Keep all HV metering resistors under oil as well. Only the low voltage leads from the divider need to exit the oil.
3. Never, ever attempt to splice any HV cable in air.
4. Use only a single continuous, properly rated HV wire or cable from the supply's output insulator to the fusor's HV terminal.
5. It is wise to run such wire in a grounded conduit, if metal, or, better still, plastic pipe to avoid arcing as the cable runs to the fusor. (double insulation)
6. All air connections should have a toroid, ball or other regularly cleaned voltage stress distribution item at the air joint.
7. Any sharp metallic point in an air connection should be totally engulfed in a heavy wad of high voltage silicone putty.
The above applies to any home brew supply at or over 30kv.
Few here have the materials or know-how to manufacture their own suitable fusor HV supply over 30kv. But all will need to run a high voltage cable from their supply to the fusor.
Richard Hull