EXP X-800C, Operating Instructions Manual, Page: 10 / 28

CHAPTER 2: POWER REQUIREMENTS
10
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.
Figure 1 illustrates a basic three-phase AC distribution sys-
tem with the loudspeaker load distributed across the three
phases. All loudspeakers are connected to common neutral
and earth-ground lines.
X-800C VOLTAGE REQUIREMENTS
The X-800C 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 subwoofer allows any combination of voltage
to GND (neutral-line-ground or line-line-ground).
If the voltage drops below 85 V (brownout), the X-800C uses
stored power to continue operating temporarily; the sub-
woofer shuts 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 X-800C
should always operate within the required volt-
age range, at least a few volts from the upper and
lower ranges. This will ensure that AC voltage varia-
tions 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 X-800C does not require a dedi-
cated 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 X-800C’s recommended operating win-
dows (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).
X-800C CURRENT REQUIREMENTS
The current draw for the X-800C is dynamic and fluctuates
as operating levels change. Since different cables and cir-
cuit 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 sec-
onds. 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 rat-
ing 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 cal-
culating the peak voltage drop in long AC cable runs
according to the following formula:
V pk (drop) = I pk x R (cable total)
■ Ultimate Short-Term Peak Current — A rating for fast-
reacting magnetic breakers.
■ Inrush Current — The spike of initial current encoun-
tered when powering on.
You can use Table 1 as a guide for selecting cable gauges
and circuit breaker ratings for the system’s operating volt-
age.
Figure 1: AC Power Distribution System
!
Line 1 Line 2 Line 3 Neutral
Earth Ground
!
Table 1: X-800C Current Draw
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 A rms 4 A rms 10 A rms
Burst Current 15 A rms 8 A rms 18 A rms
Ultimate Short-Term
Peak Current 22 A peak 11 A peak 25 A peak
Inrush Current <7 A peak <7 A peak 10 A peak