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CHAPTER 1
Current Requirements
Each UPJ-1P requires approximately 3 A rms max at 115
V AC for proper operation. This allows up to ve UPJ-1Ps
to be powered from one 15 A breaker at 115 V and up to 9
loudspeakers at 230 V.
The UPJ-1P presents a dynamic load to the AC mains,
which causes the amount of current to uctuate 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 cor-
respond to circuit breaker and cable specications.
The maximum long-term continuous current is the maxi-
mum 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 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 below as a guide when selecting cable gauge
size and circuit breaker ratings for your operating voltage.
Table 1.1: UPJ-1P 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 within the operating
ranges.
The minimum electrical service amperage required by a
UPJ-1P 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 volt-
age drops at the service entry.
Power Connector Wiring
The UPJ-1P loudspeaker requires a grounded outlet. It is
very important that the system be properly grounded in or-
der to operate safely and properly. Use the AC cable wiring
diagram in Figure 1.2 to create international or special-pur-
pose power connectors:
brown = hot
blue = 
neutral
yellow/green =
earth ground
(chassis)
Figure 1.2. AC cable color code
If the colors referred to in the diagram don’t correspond to
the terminals in your plug, use the following guidelines:
Connect the blue wire to the terminal marked with an N
or colored black.
Connect the brown wire to the terminal marked with an
L or colored red.
Connect the green and yellow wire to the terminal
marked with an E or colored green or green and yellow.
ELECTRICAL SAFETY ISSUES
!
CAUTION: The UPJ-1P requires a ground
connection. Always use a grounded outlet
and plug.