[Amps] AC wiring

[Gudguyham@aol.com]

In a message dated 10/19/2005 4:14:03 P.M. Eastern Standard Time,  
amps080605 at w4zt.com writes:

If we  use your factual example of 2300 watts OUTPUT, then using 60% 
efficiency  will give us 3833 watts input power, add a few amp pieces for 
another 100  watts for 3933 watts. Use 90% efficiency for the power 
supply and you've  got 4370 watts.  That's 18.21 amps at 240 volts. Add a 
blower at an  amp and you're up to 19.21 amps.   #14 wire on a 15 amp 
circuit  wouldn't be the right choice for your example. Actually, neither 
would #12  on a 20 amp circuit. Drop the mains voltage, change the tap in 
your power  supply to maintain your B+ and your mains current is even  higher.




I don't refute  what you have said here, however, it does NOT change  the 
fact that the Ameritron AL-1500 comes with a 15A 240 plug and  15A  fuses.  On 
SSB or Cw this amp will perform just fine on a 20A circuit with  #12 wire.  The 
amp is NOT a continuous load and therefore no derating  factor need be taken 
into consideration.  18 amps on #12 wire with a non  continuous load is fine.  
The reason for the circuit breaker is to protect  the circuit for an overload. 
 If the wire gets too hot the breaker will  trip.  Just for example, an 
electrical stove/oven is usually fed with #6  wire rated for 50 amps.  If you have 
ever hooked one up, you will see that  they use either #12 or #10 wire at the 
terminals you just hooked your #6  to.  Insulation is another factor in wire 
rating.