REVISED AWG Wire Table for Coilers

From:  Malcolm Watts [SMTP:MALCOLM-at-directorate.wnp.ac.nz]
Sent:  Tuesday, April 14, 1998 4:42 PM
To:  Tesla List
Subject:  Re: REVISED AWG Wire Table for Coilers

Hi Tom, all,

> From:  Thomas McGahee [SMTP:tom_mcgahee-at-sigmais-dot-com]
> Sent:  Thursday, April 09, 1998 7:59 PM
> To:  Tesla-2; tesla-at-pupman-dot-com
> Subject:  REVISED AWG Wire Table for Coilers
> Fellow Coilers,
> A few people e-mailed me to say that I was a bit conservative on the amp
> ratings
> for the AWG wire table I e-mailed to the TESLA and TESLA-2 lists.
> I realize that we Coilers love to push things to the limit. In going back over
> my AWG sources I did find one source that went as high as 23.679 amps for
> AWG #10. Someone mentioned that UL codes allowed 23 amps for AWG #12. Such a
> large value must be assuming the wire is enclosed in a metal conduit which
> is acting as a heat sink. I have re-written my program to reflect a Max
> recommended continuous current of 23.679 amps for a #10 AWG bare copper wire
> cooled by ambient air.
> I am sorry if sending this second revised AWG table means a few more seconds
> of download time for the List members. Dump the earlier table and file this
> revised table away for future reference.
> Hope this helps.
> Fr. Tom McGahee

As the length of the conductor is reduced and cooling is increased, 
you can push current densities to a pretty high value. What would 
overheat and fail in a 50Hz transformer winding at a certain power 
level would be total overkill in a switchmode transformer as the I^2.R
loss is drastically reduced due to the short length of wire used. 
Check out the conductor (tinned copper) thickness in a glass 10 Amp 
fuse.  Thanks for the table and thanks to Antonio for the equation.