Current Requirements - Meyer Sound MILO Operating Instructions Manual

CHAPTER 1
NOTE: Refer to Appendix B for details
on the MILO loudspeaker's AC voltage
requirements.
After applying AC power, the proper operating voltage is
automatically selected, but the system is muted. During the
next three seconds the following events occur:
1. The primary fans turn on.
2. The main power supply slowly ramps on.
3. The green Active LED on the user panel lights up,
indicating that the system is enabled and ready to pass
audio signals.
CAUTION: If the Active 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 either safe
operating range (brownout), MILO uses stored energy to
continue functioning briefly, and shuts down only if voltage
does not rise above the low boundary before MILO's
storage circuits are depleted. How long MILO 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
either range, the power supply rapidly turns off, preventing
damage to the unit.
NOTE: If voltage fluctuates within either
operating range, automatic tap selection
stabilizes the internal operating voltage. This tap
selection is instantaneous, and there are no audible
artifacts.
If MILO shuts down due to either low or high voltage, its
power supply automatically turns on again after three
seconds if the voltage has returned to either normal
operating window. If the MILO loudspeaker does not turn
back on after ten seconds, remove AC power immediately
(see previous Caution).
6
NOTE: It is recommended that the supply
be operated in the rated voltage windows 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.

CURRENT REQUIREMENTS

The MILO 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 long-term continuous current is the
maximum rms current during a period of at least ten
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 apprximately 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 below as a guide when selecting cable gauge
size and circuit breaker ratings for your operating voltage.
Table 1.1: MILO Current Ratings
Current Draw 115 V AC
Idle current 1.1 A rms
Max. long-term 11.2 A rms
continuous
Burst current 14.4 A rms
Ultimate short- 32 A pk
term peak
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.
230 V AC 100 V AC
0.55 A rms 1.3 A rms
5.6 A rms 12.9 A rms
7.2 A rms 16.6 A rms
16 A pk 37 A pk