[Elecraft] KPA500 Voltage?

Ed Cole kl7uw at acsalaska.net
Wed Nov 16 00:28:18 EST 2022


PS:  Only the mains line is aluminum and connections treated with 
antioxidant paste.  All new wiring in the new hamshack is copper (12-2 
for 120vac and 10-3 for 240vac).

The 3000w Meanwell 50v PS is served with a short 10-3 line to a 30A 
twist-lock receptacle in a floor mounted utility box with three foot 8-3 
jumper to the PS (All copper).  Max load is 12.5A; fused at 15A. 
Meanwell has internal overload and overtemp auto shutdown.

Main thermostat (3000w) is programmable, so heat load will only be 
highest when the area is occupied.  The workshop has manual thermostat 
which can be turned off when shop not in use (dividing wall is insulated 
between hamshack and workshop).

The building will have a monitored (24/7) security system with smoke 
monitors.  Monitor service calls police/fire dept if no one answers the 
phone.  Two FD stations within five miles.

I guess I could add thermistors to the mains contacts to alert overtemp. 
  I use such a system on my QRO amp heatsinks to protect the amps 
(auto-overtemp shutdown of B+).

I will monitor initial application of 240vac power to look for problems.
In my college years I was a Electrician assistant for one summer job and 
got a good practical education installing ckts (even 440 industrial).

Thanks for all the comments!

Ed - KL7UW


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