Meyer Sound M1D - Manual (Page 10)

4
CHAPTER 1
5
CHAPTER 1
Voltage Requirements
The M1D and M1D-Sub loudspeakers operate safely and
without audio discontinuity if the AC voltage stays within
the operating window of 90 to 264 V AC, at 50 or 60 Hz.
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 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 loudspeakers use stored
energy to continue functioning briefly, and shut 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 of the
range, the power supply can 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 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
or cause damage to the power supply.
CURRENT REQUIREMENTS
Each M1D and M1D-Sub loudspeaker requires
approximately 3 A rms max at 115 V AC for proper
operation. This allows up to five M1D and/or M1D-Sub
loudspeakers to be powered from one 15 A breaker.
The M1D and M1D-Sub loudspeakers present 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 long-term continuous current is the
maximum rms current during a period of at least 10
seconds. It is used to calculate the temperature increase
in cables, in order to select a cable size and gauge that
conforms to electrical code standards. It is also used to
select the rating for slow-reacting thermal breakers.
The burst current is the maximum rms current during a
period of approximately one second, used to select the
rating of 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 short-term peak current is used to select the
rating of fast reacting magnetic breakers.
Use Table 1.1 as a guide when selecting cable gauge size
and circuit breaker ratings for your operating voltage.
Table 1.1 M1D/M1D-Sub Current Ratings
Current Draw 115 V AC 230 V AC 100 V AC
Max. long-term
continuous 3.2 A rms 1.65 A rms 3.7 A rms
Burst current 5 A rms 2.5 A rms 5.8 A rms
Ultimate short-
term peak 17 A pk 8.5 A pk 20 A pk
Idle current 0.41 A rms 0.33 A rms 0.42 A rms
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
M1D/M1D-Sub 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.