I have a question regarding the ZV28 and voltages, power draw.

When splitting a 240V 30A outlet into two separate ones will the voltage still stay at 240V?

When I think about the amp draw, I am under the impression that when voltage doubles current draw reduces by half so if one amplifier peaked at 20A on 120V, then two would only peak to 20A on 240V. However, there is a high probability I am wrong. PowerCON is new to me. As the saying goes, better safe than sorry!
  • 2 powered passive ZV28s
  • 2 powered ZV28s
  • 2 DV12s
  • 2 DV8s
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Hey there ADJS,

Yes, the voltage remains the same. When adding a second amplifier, the current doubles. The current limit of the amplifier doesn’t change when the voltage changes. When running on any voltage, the amplifiers limit their current intake to 16.5A after 1 second regardless of the line voltage. For less than one second they can draw over 30A each. The nature of a breaker is that it trips based upon current flow over time. The more current, the faster it trips. 20A breakers will allow much more than 20A for short periods of time.

Current (flow), not voltage (pressure), is what heats up wires and connectors, so current is the limiting factor for connector and cable ratings, and breakers. The reason you get more output from the amp on 240V is that when there is more voltage, there is more power available at the same current flow limit. If you put two amps on the same circuit, they will draw double the current of one amp. At 120V 16.5A allows only 1980W of continuous power. At 240V, with the same limit of 16.5A, the power available is 3960W.  On 240V, two amps at their limits would be drawing 33A of current flow, which would make 7920W of power available. (These numbers are all continuous draw and assume no losses. In reality, audio amplifiers don't demand continuous draw because of the dynamic nature of music. The amplifiers have storage capacity that allows them to deliver more power for brief periods and, due to the varying impedances of the woofers, the amplifiers don’t need to pass that much current very much of the time. These particular amplifiers run between 93 and 98% efficient, so 2 to 7% operating losses.)  

The bottom line is that connectors are rated for current flow. A L6-30 outlet is rated for 30A of continuous current flow. The blue and white PowerCONs are rated for 20A of current flow. Each amplifier draws a maximum continuous 16.5A of current. It’s fine to run 33A of maximum continuous current flow through a 30A rated connector, but it is less well advised to run the same flow through a 20A rated connector. If the connector heats up, it will not only wear out, but it will add resistance which will reduce the available voltage and the available current. The chances are you would not have a problem with using the 20A connectors because all these devices are rated quite conservatively but why cause a bottleneck if you don’t have to?

David Lee
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