Power Requirements
The Acheron loudspeaker combines advanced loudspeaker technology with equally advanced power capabilities. Understanding power distribution, voltage and current requirements, and electrical safety guidelines is critical to the safe operation of the Acheron.
AC Connector
The Acheron AC connector supplies AC power to the unit and is located on its rear user panel. The Acheron can be equipped with one of the following AC connectors:
IEC 309 male inlet connector
NEMA L6-20 (twistlock) male inlet
The Acheron requires a grounded outlet. To operate safely and effectively, it is extremely important that the entire system be properly grounded.
If you replace the included AC power cable, make sure to use a cable that is wired correctly and equipped with the appropriate power plug (on the other end) for the area in which you will operate the unit.
AC Power Cable with Edison Adapter
The Acheron can be powered from a standard three-prong Edison outlet with an L6-20 to Edison adapter (available for purchase from Meyer Sound; PN 27.033.024.03).
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L6-20 to Edison AC Power Cable Adapter
AC Connector Wiring
When wiring international or special-purpose AC power cables and connectors, use the following wiring scheme:
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AC Cable Wiring Scheme
Connect the blue wire to the black terminal, or the terminal marked with an N.
Connect the brown wire to the red terminal, or the terminal marked with an L.
Connect the yellow and green wire to the green (or green and yellow) terminal, or the terminal marked with an E.
Caution
When creating AC power cables and distribution systems, it is important to preserve AC line polarity and connect the earth ground on both ends of the cable. The Acheron requires a grounded connection. Always use a grounded outlet and plug. It is extremely important that the system be properly grounded to operate safely and properly. Do not ground-lift the AC cable.
AC Power Distribution
All components in an audio system (self-powered loudspeakers, processors, etc.) must be properly connected to an AC power distribution system, to ensure that AC line polarity is preserved and that all grounding points are connected to a single node or common point using the same cable gauge as the neutral and line cables.
Note
Improper grounding of connections between loudspeakers and the rest of the audio system may produce noise or hum, or cause serious damage to the input and output stages of the system’s electronic components.
Caution
Before applying AC power to any Meyer Sound self-powered loudspeaker, make sure that the voltage potential difference between the neutral and earth-ground lines is less than 5 V AC.
The figure below illustrates a basic three-phase AC distribution system with the loudspeaker load distributed across the three phases. All loudspeakers are connected to common neutral and earth-ground lines.
AC Power Distribution System
Acheron voltage requirements
The Acheron operates safely and continuously when the AC voltage stays within 85–134 V AC and 165–264 V AC at 50 or 60 Hz. The loudspeaker allows any combination of voltage to GND (neutral-line-ground or line-line-ground).
If the voltage drops below 85 V (brownout), the Acheron uses stored power to continue operating temporarily; the loudspeaker will shut down if the voltage does not rise above the low boundary before the stored power is used.
If the voltage rises above 275 V, the power supply could become damaged.
Caution
The power source for the Acheron should always operate within the required voltage range, at least a few volts from the upper and lower ranges. This ensures that AC voltage variations from the service entry—or peak voltage drops due to cable runs—will not cause the loudspeaker’s amplifier to cycle on and off or cause damage to the power supply.
Tip
Since the Acheron does not require a dedicated neutral line, and it can tolerate elevated voltages from the ground line, it can be connected to line-line terminals in 120 V, 3-phase Wye systems. This results in 208 V AC between lines (nominal) and therefore draws less current than when using 120 V AC (line-neutral). Make sure that the voltage remains within the Acheron’s recommended operating windows (85–134 V AC and 165–264 V AC). The ground line must always be used for safety reasons and the line-to-ground voltage should never exceed 250 V AC (typically 120 V AC from line-to-ground).
Acheron Current Requirements
The current draw for the Acheron is dynamic and fluctuates as operating levels change. Since different cables and circuit breakers heat up at varying rates, it is important to understand the following types of current ratings and how they affect circuit breaker and cable specifications.
Idle Current — The maximum rms current during idle periods.
Maximum Long-Term Continuous Current — The maximum rms current during a period of at least 10 seconds. The Maximum Long-Term Continuous Current is used to calculate temperature increases for cables, to ensure that cable sizes and gauges conform to electrical code standards. The current rating is also used as a rating for slow-reacting thermal breakers.
Burst Current — The maximum rms current during a period of around one second. The Burst Current is used as a rating for magnetic breakers. It is also used for calculating the peak voltage drop in long AC cable runs according to the following formula:
V pk (drop) = I pk x R (cable total)
Maximum Instantaneous Peak Current — A rating for magnetic breakers.
Inrush Current — The spike of initial current encountered when powering on.
You can use the following tables as guidelines for selecting cable gauge and circuit breaker ratings for the system’s operating voltage.
Current Draw | 115 V AC | 230 V AC | 100 V AC |
|---|---|---|---|
Idle Current | 0.71 A rms | 0.38 A rms | 0.79 A rms |
Maximum Long-Term Continuous Current | 5.8 A rms | 2.8 A rms | 6.3 A rms |
Burst Current | 6.4 A rms | 3.2 A rms | 7.2 A rms |
Maximum Instantaneous Peak Current | 26 A peak | 14 A peak | 28 A peak |
Inrush Current | 7 A peak | 7 A peak | 10 A peak |
Current Draw | 115 V AC | 230 V AC | 100 V AC |
|---|---|---|---|
Idle Current | 0.64 A rms | 0.32 A rms | 0.85 A rms |
Maximum Long-Term Continuous Current | 8.8 A rms | 4.4 A rms | 10.0 A rms |
Burst Current | 19 A rms | 9.5 A rms | 22 A rms |
Maximum Instantaneous Peak Current | The USW-112P compact narrow subwoofer provides big bass sound for very tight spaces. Its compact rectangular enclosure and slanted connector panel enable flushmounting of the cabinet against wall surfaces, reducing required installation depth to 12 inches, including connectors. | 20 A peak | 45 A peak |
Inrush Current | 7 A peak | 7 A peak | 10 A peak |
The minimum electrical service amperage required by an Acheron loudspeaker system is the sum of the Maximum Long-Term Continuous Current for each loudspeaker. An additional 30 percent above the minimum amperage is recommended to prevent peak voltage drops at the service entry.
Note
For best performance, the AC cable voltage drop should not exceed 10 V, or 10 percent at 115 V and 5 percent at 230 V. Make sure that even with AC voltage drops that the AC voltage always remains within the operating windows.
Powering Up the Acheron
When AC power is applied to the Acheron its Intelligent AC™ power supply automatically selects the correct operating voltage, allowing it to be used internationally without manually setting voltage switches. In addition, Intelligent AC suppresses high-voltage transients up to several kilovolts, filters common mode and differential mode radio frequencies (EMI), and sustains operation temporarily during low-voltage periods.
When powering up the Acheron, the following startup events take place over several seconds.
Audio output is muted.
Voltage is detected and the power supply mode is automatically adjusted as necessary.
The primary ultra-low-noise fan turns on.
The power supply ramps up.
The green Active LED on the user panel lights up, indicating the loudspeaker is ready to output audio.
Caution
If the Active LED does not light up, or the Acheron does not output audio after ten seconds, remove AC power immediately and verify that the voltage is within the required range. If the problem persists, contact Meyer Sound Technical Support.
If either of the loudspeaker’s circuit breakers trip (the white center buttons disengage), do NOT reset and reapply power. Disconnect the AC power and contact Meyer Sound Service Department for instructions on how to proceed.
Electrical safety guidelines
Pay close attention to these important electrical and safety guidelines.
The Acheron requires a grounded outlet. Always use a grounded outlet and plug.
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Make sure the AC power cable for the loudspeaker has the appropriate power plug (on the other end) for the area in which you will operate the loudspeaker.
Do not operate the unit if the power cable is frayed or broken.
Keep all liquids away from the Acheron to avoid hazards from electrical shock.