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Electrical requirement in the shack to support an amplifier

Hi Fellow Amateur,

Can someone please tell me what's the optimal circuit in the shack to support max power limit of an amplifier 1500 Watt? Is it 220V 10amps?

Best Answer

  • Alan
    Alan Member ✭✭✭✭
    Answer ✓

    The breaker is sized to protect the wire.....not the amplifier current draw.

    The wire is sized to not cause an excessive voltage drop, when supplying the amplifier power, over a reasonable distance.

    can use #10 wire with a 30 amp breaker

    can use #12 wire with a 20 amp breaker.

    Alan. WA9WUD


  • Craig_KØCF
    Craig_KØCF Member ✭✭✭

    220 V 10 A circuit is not adequate for a modern solid-state amplifier. Most are on the order of 50% efficient, which means 3,000 watts input for 1,500 watts output. Figure an efficiency of 80% for the power supply, and it takes 3,750 watts from the AC mains. At 220 V, that is about 17 amperes.

    My shack circuit is 220 V 20 A and it runs my KPA1500 just fine.

    73, Craig KØCF

  • KD0RC
    KD0RC Member, Super Elmer Moderator

    Hi Angelo, you should look at the specs for your amplifier to be sure what it requires. If it is the PGXL, it takes a 15 amp dedicated circuit. Generally, you want a dedicated circuit for this kind of gear.

  • Ken AG2K
    Ken AG2K Member ✭✭

    So if I read this correctly the PGXL needs to be a 15 amp dedicated 220 outlet? Any recommendations on the type of outlet to use? Twist lock?



  • KD0RC
    KD0RC Member, Super Elmer Moderator

    Hi Ken, I think the outlet type is at least partially dependent on the electrical codes in your area.

  • Ken AG2K
    Ken AG2K Member ✭✭

    I'm going to have to try to look that up. I'm in CT and as far as I've seen with the limited amount I know it seems to be pretty "standard" and they follow a national standard. Knowing that Google is my friend I've not been to lucky with looking this up.


  • Dave_WB1S
    Dave_WB1S Member ✭✭

    Voltage at my house is closer to 240 VAC. I just measured it at 241 VAC. 120 and 240 are closer to today's standards. For my PGXL I use a 20 AMP 2 pole breaker and #12 romex. I use a 20 Amp 250-Volt NEMA 6-20P 3-Prong plug and a separate chassis ground wire PGXL ground lug to the common shack ground bus.

  • Dave_WB1S
    Dave_WB1S Member ✭✭


    Oops just went to the cellar to check my panel. Previous post by Ken 15 AMP breaker is correct for PGXL not 20. Sorry for my mistake. I use 15 Amp 250-Volt NEMA 6-15P 3-Prong plug and 14/2 romex.


  • John KB4DU
    John KB4DU Member ✭✭✭✭

    Decades ago the nominal line voltage was 110/220. As power demand increased the nominal line voltage was increased to 115/230. Now its 120/240. I guess good for the power companies, maybe not so good for us if the trend continues.

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