maximum voltage across a wire
maximum voltage across a wire
(OP)
I am a hobbyist for small electrical projects and chemical engr. by profession. I have an 18AWG wire connected to 12V DC and giving power to a load with 10A current passing through wire. I want to put a higher load with 48V DC but the current will be 10A again. In 3rd case I want to use same wire but with 220V AC and 10A current. Can the same 18AWG wire handle the 10A current in each case of different voltages? The wire specs tell me only the current rating, nowhere voltage rating is mentioned for the wire.
Is there any limit to the maximum voltage across the wire?
Thanks,
Is there any limit to the maximum voltage across the wire?
Thanks,






RE: maximum voltage across a wire
RE: maximum voltage across a wire
I often follow this table:
http://www.powerstream.com/Wire_Size.htm
Keith Cress
kcress - http://www.flaminsystems.com
RE: maximum voltage across a wire
RE: maximum voltage across a wire
Keith Cress
kcress - http://www.flaminsystems.com
RE: maximum voltage across a wire
xnuke
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RE: maximum voltage across a wire
As a gross general rule, most "building", "appliance", "fixture" or "hookup" wire that you can buy off the shelf in a store will be rated for 300V or 600V. Wire classified as "Low Voltage", "communication" or "automotive" wire will likely be rated 50V or less. Not matter what, at 48V, you are probably fine, but at 220V, make sure you select one of the other types.
But I also agree with the others, 10A is too much for 18ga. except in some very specialized circumstances. Be careful looking up wire ampacity on Internet sources, some are referring to the ampacity of the bare coper conductors under laboratory conditions. Real world ampacity ratings are based on testing at common case ambient environments and thermal ratings of the insulation. That's why the NEC tables are what must be used. Those tables will be based on the insulation type, not just the copper inside.
"You measure the size of the accomplishment by the obstacles you had to overcome to reach your goals" -- Booker T. Washington
RE: maximum voltage across a wire
RE: maximum voltage across a wire
RE: maximum voltage across a wire
There should be a voltage rating on the wire same as the temp and AWG. If not, it should be on the spool. If not, you should constrain the wire to low voltage service like automotive or 50V and less or to trying bags shut, hanging bird feeders, or store it in the circular file cabinet.
Keith Cress
kcress - http://www.flaminsystems.com
RE: maximum voltage across a wire
You don't want to put 120 Volts on any wire that does not have a voltage rating and UL approvals.
Upgrading to #16 is a good idea. When you buy the #16 wire, select one that has the voltage rating and approval information printed on the wire.
Bill
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