[Elecraft] KPA800/1500 Power Question

[Vic Rosenthal]

Jim Harris wrote:

> Now my real question.  Does anyone know what the AC
> power requirements are for both models.  I'm bringing
> more power into my shack this summer and it would be
> great to know what power is required.  

I don't know the actual power requirements, Jim, but I would expect 
overall efficiency of around 50%, taking into account the power supply 
and amplifier efficiency.  However, if you are installing ANY high power 
amplifier, it's generally thought that a 20-amp 240V circuit is 
appropriate.  This is probably more than you will need for a KPA800, 
which would probably work fine with 15 or perhaps even 10 amp service at 
240V, but (depending on the length of the line to your service entrance) 
it probably means no. 12 wire, which is not a big deal.  An electrician 
can tell you what you need to do to meet code in terms of wire size, 
type of conduit, type of receptacles, etc.

What I did was install 20 amp breakers and use no. 10 wire to ensure the 
minimum voltage drop under load.  I brought out 4 wires:  two hots, one 
neutral, and one ground.  The neutral is ONLY connected to the ground at 
the service entrance, noplace else.  Most amplifiers only need the two 
hot leads and ground (there are exceptions).  I use the hot-to-neutral 
connections to provide two 120v circuits for other shack equipment.

I would not run a 1KW amp on a 120v line if I could avoid it, due to the 
greater voltage drop that would be incurred.  I understand that the 
KPA800 is capable of 1000w or more output on CW (it's limited to 800w on 
SSB due to increased IMD at higher power levels).

-- 
73,
Vic, K2VCO
Fresno CA
http://www.qsl.net/k2vco