CHAPTER 1
VOLTAGE AND CURRENT REQUIREMENTS
M2D Voltage Requirements
The M2D loudspeaker operates safely and without audio discontinuity if the AC voltage stays within the operating window of 90 to 265 volts AC, at 50 to 60 Hz.
The M2D can withstand continuous voltages up to 265 Volts and allows any combination of voltage to GND (that is
CAUTION: Continuous voltages higher than 265 volts may damage your M2D.
After applying AC power, the system is muted while the circuitry charges up and stabilizes. During the next two seconds the following events occur:
1.The power supply fan turns on.
2.The main power supply slowly ramps on.
3.The green On/Temp LED on the User Panel lights up, indicating that the system is enabled and ready to pass audio signals.
CAUTION: If the On/Temp LED does not illuminate or the system does not respond
to audio input after ten seconds, remove AC power immediately. Verify that the voltage is within the proper range. If the problem persists, please contact Meyer Sound or an authorized service center.
If voltage drops below the low boundary of its safe operating range (brownout), the M2D loudspeaker uses stored energy to continue functioning briefly, and shuts down only if voltage does not rise above the low boundary before storage circuits are depleted. How long the loudspeaker will continue to function during brownout depends on the amount of voltage drop and the audio source level during the drop.
If the voltage increases above the upper boundary, the unit may be damaged.
NOTE: It is recommended that the supply be operated in its rated voltage window at least
a few volts away from the turn on/off points. This ensures that AC voltage variations from the service entry, or peak voltage drops due to cable runs, do not cause the amplifier to cycle on and off. It also keeps high voltage from damaging the power supply.
M2D Current Requirements
Each M2D loudspeaker requires approximately 3 A rms max at 115 volts AC for proper operation. This allows up to five M2D loudspeaksers to be powered from one 15 A breaker.
The M2D loudspeaker presents a dynamic load to the AC mains, which causes the amount of current to fluctuate between quiet and loud operating levels. Since different cables and circuit breakers heat up at varying rates, it is essential to understand the types of current ratings and how they correspond to circuit breaker and cable specifications.
The maximum
The burst current is the maximum rms current during a period of approximately one second, used to select the rating for most magnetic breakers and to calculate the peak voltage drop in long AC cables according to the formula:
V pk (drop)= I pk x R (cable total).
The ultimate
Use Table 1.1 below as a guide when selecting cable gauge size and circuit breaker ratings for your operating voltage.
Table 1.1: M2D Current Ratings
Current Draw | 115 V AC | 230 V AC | 100 V AC | |||
Max. | 3.1 | A rms | 1.6 | A rms | 3.6 | A rms |
continuous |
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Burst current | 3.2 | A rms | 1.6 | A rms | 3.7 | A rms |
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Ultimate short- | 5.8 | A pk | 2.9 | A pk | 6.7 | A pk |
term peak |
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Idle current | 0.35 A rms | 0.35 A rms | 0.35 A rms | |||
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NOTE: For best performance, the AC cable voltage drop should not exceed 10 volts, or 10 percent at 115 volts and 5 percent at 230 volts.
Make sure that even with the AC voltage drop the AC voltage always stays in the operating windows.
The minimum electrical service amperage required by an M2D system is the sum of each loudspeaker’s maximum continuous rms current. An additional 30 percent above the minimum amperage is recommended to prevent peak voltage drops at the service entry.
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