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CHAPTER 2
The MJF-212A monitor combines advanced self-powered
loudspeaker technology with equally advanced power
capabilities. Understanding the power distribution, voltage,
and current requirements, as well as electrical safety
issues, is critical to the safe and correct operation and
deployment of the MJF-212A monitor. The MJF-212A uses
a PowerCon® power connector with a loop output and
complies with worldwide product safety standards.

AC POwER DISTRIbUTION

All audio components (self-powered loudspeakers, mixing
consoles, processors, etc.) must be properly connected to
the AC power distribution, preserving AC line polarity and
connecting earth ground such that all grounding points
are connected to a single node or common point using the
same cable gauge as the neutral and line cables.
NOTE: Improper grounding connections
between loudspeakers and the rest of the
audio system may produce noise or hum, or cause
serious damage to the input and output stages in
the system’s electronic equipment.
CAUTION: Before applying AC to any Meyer
Sound self-powered loudspeaker, make sure
that the voltage potential difference between neutral
and earth ground is less than 5 V AC.
Figure 2.1 shows a sample three-phase AC distribution
system, with the load between loudspeakers distributed
among the three phases and all of the loudspeakers
connected to common neutral and earth-ground points.
Figure 2.1. A sample AC power distribution block diagram

lOOPING AND CAblING

MJF-212A stage monitors use a PowerCon 3-pole AC
mains system with locking connectors to prevent accidental
disconnection. Two female inlets (one colored blue and the
other gray) are provided. To loop units, simply attach a cable
from the gray connector of the first loudspeaker system to
the blue connector of the looped unit (Figure 2.2).
Figure 2.2. PowerCon input and loop out AC connectors
CAUTION: A 10-foot blue power connector
cable is provided with MJF-212A
loudspeakers. This cable is rated for 15 amps.
When using it, do not loop more than two MJF-212A
loudspeakers from the loop out connector when
connected at 115 V (three total in the same circuit),
and not more than five when driven at 230 V (six
total in the same circuit).
CAUTION: If you replace the AC power cable
shipped with the loudspeaker, make sure that
you select the correct power plug for the AC power
in the area in which you will use the MJF-212A
monitor. In addition, the connector must be rated for
the load of all the MJF-212As looped to the same
power plug.
TIP: A cable-mount gray loop out PowerCon
connector is provided with MJF-212A
monitor to make looping cables.
CHAPTER 2: POwER REqUIREmENTS