Meyer Sound UPA-1P - Manual (Page 4)

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AC Power
The UPA-P uses a PowerCon locking 3-pole AC mains
connector that prevents inadvertent disconnection. The
unit must have the correct power plug for the AC power
in the area in which it will be used.
When AC power is applied to the UPA-P, the Intelligent
AC
tm supply automatically selects the correct operating
voltage, allowing the UPA-P to be used internationally
without manually setting voltage switches. The Intelligent
AC supply performs the following protective functions
to compensate for hostile conditions on the AC mains:
• suppresses high voltage transients up to several
kilovolts
• filters EMI (radio frequencies and noise present on
the AC line)
• sustains operation during low-voltage periods,
which minimizes audio discontinuity
• provides soft-start power-up, which eliminates high
inrush current
The UPA-P can withstand continuous voltages up to
264V and allows any combination of voltage to GND (i.e.
Neutral-Hot-GND, Hot-Hot-GND). Continuous volt-
ages higher than 264V may damage the unit.
Voltage Requirements
The UPA-P operates safely and without audio disconti-
nuity if the AC voltage stays within the range 88–264V,
47–63 Hz. After applying AC power, the system is muted
while the circuitry charges up and stabilizes. After two
seconds, the On/Temp. LED on the user panel illumi-
nates green, the system unmutes and is ready to pass
audio signals. If the On/Temp. LED does not illuminate
or the system does not respond to audio input after ten
seconds, consult the Troubleshooting section.
The UPA-P’s power supply uses stored energy to continue
functioning for about 10 AC cycles if the voltage decreases
below 88V (a condition known as brownout). The precise
length of time the unit will continue to function during
brownout depends on the operating level and how low
the voltage drops. The unit turns off if the voltage does
not increase above 88V for 1 to 5 seconds. If the UPA-P
shuts down due to brownout, the power supply auto-
matically turns on if the voltage returns to the normal
operating range. If the UPA-P does not turn back on after
ten seconds, consult the Troubleshooting section.
NOTE: We recommend that the supply be operated at
least a few volts away from the upper and lower bounds
of the operating range to avoid possible shutdown.
Current Requirements
Each UPA-P requires approximately 3 A rms @115V
(1.5 A rms @230V) for proper operation, allowing up to
five UPA-Ps to be powered from one 15 A circuit. How-
ever, we recommend powering no more than three UPA-Ps
per 15 A branch to allow a 30% margin for peak voltages.
The UPA-P presents a dynamic load to the AC mains
which causes the amount of current to fluctuate between
quiet and loud operating levels. This affects the number
of UPA-Ps that can be used for a given breaker type. Since
different types of cables and circuit breakers heat up and
trip 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 continuous RMS current is the maximum
RMS current over a duration of at least 10 seconds. It is
used to calculate the temperature increase in cables, which
is used to select cables that conform to electrical code
standards. It is also used to select the rating for slow-
reacting thermal breakers.
The maximum burst RMS current is the maximum RMS
current over a one second duration. It is used to select the
rating for most magnetic breakers.
The maximum instantaneous peak current during burst
is used to select the rating for fast-reacting magnetic
breakers and to calculate the peak voltage drop in long
AC cables according to the formula
V pk
drop
= I pk x R total cable
Engagement
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1
2
1
3
Separation