On April 6, 2008 at 22:26, billski said...
Why don't you just cord cut at the male end to the proper
lenght and terminate with a new end. I do this all of
the time in my large MA racks makes for a great way to
manage my AC cords. Good quality ends can be found at
HD or any electrical supplier.
Regardless of the electrical contractor issues, you undo the UL or CSA rating. Would you buy screw-on ends and wire on a spool, and make your own cables? If not, why not? Maybe because home-made cables don't feel right?
On April 7, 2008 at 17:47, idodishez said...
It gets jokes around here of "You cant flood the place,
but you can burn it down" or something like that.
Mr. Stanley hasn't been there, has he?
On April 6, 2008 at 23:00, bcf1963 said...
So, the issue here is power dissipation in the power cord,
and voltage drop in the conductors causing issues for
the electronics.
Exactly. I'm glad not to be the only one doing the math to investigate things like this.
...works out to the 16AWG being 0.0268 ohm/m
and the 18 AWG being 0.0428 ohm/m
This means the impedance of the 18AWG is 0.016 ohm/m more.
Whhops! Amateur mistake here, sorry to say. Resistance is a DC measurement that ignores the effects of capacitance and inductance. Impedance is an AC measurement that includes resistance plus the magnitudes of the capacitive and inductive reactances, and it is frequency dependent because the effects of those reactances act opposite to one another and can actually cancel out. So you mean resistance, like you said before.
So, we can calculate the length of 18AWG cord that would
present the same impedance as the factory supplied 16AWG
cord.
Well, resistance, but, yeah. I won't say it again, I promis.
That length would be the difference in impedance divided
by the OEM cord impedance. For this case that works out
to 0.016 ohm/m divided by 0.0268 ohm/m, or 59.7%.
To be clear, since this quote doesn't show the other quote, the first cord was five feet long.
So, as long as you replace the 16AWG cord, with a 18AWG
cord that is less than 59.7% of the length of the OEM
cord, you should be fine. That works out to 2.95', or
for practical purposes 3'.
Exactly.
So, this EE says, don't sweat it! You're not going to
have any problems.
Except for the definitions of resistance and impedance. This usually doesn't matter until one trots out the math or tries to tell someone that an eight ohm speaker will measure about 5 or 6 ohms on a meter.
