CONTRACTOR PRECISION SERIES
Owner‘s Manual 7
2.2 Operating Voltage
The power amplifier receives its power supply via the MAINS IN connector. During installation, always separate the power
amplifier from the mains. Connect the power amplifier only to a mains network, which corresponds to the requirements
indicated on the type plate.
Mains Operation & Resulting Temperature
The power drawn from the mains network is converted into output power to feed the connected loudspeaker systems and into
heat. The difference between power consumption and dispensed power is called power dissipation (P
d
). The amount of heat
resulting from power dissipation might remain inside of a rack-shelf and needs to be diverted using appropriate measures.
The tables on page 35 allow the determination of power supply and cabling requirements. The tables are meant as auxiliary
means for calculating temperatures inside of a rack-shelf system/cabinet and the ventilation efforts necessary.
The column P
d
lists the leakage power in relation to different operational states. The column BTU/hr lists the dispensed heat
amount per hour. The following factors allow direct proportional calculation of the mains current I
mains
for different mains
supply voltages: 100 V = 2.3, 120 V = 1.9, 220 V = 1.05, 240 V = 0.97.
2.3 Mains Switch
The Mains Switch on the front panel separates the power amp from the mains. Turning
the Mains Switch to ON starts booting up the power amp. A soft start circuit compensates
mains inrush current peaks and thus prevents the automatic cutout of the mains from
reacting when switching on the power amplifier. Speaker system switch-on is delayed by
approximately 4 seconds, effectively suppressing any possible power-on noise, which
otherwise might be heard through the loudspeakers.
2.4 Mounting
CPS amplifiers have been designed for installation in a conventional 19-inch rack case. Attach the power amp with its frontal
rack mount ears using 4 screws and washers as shown in following illustration. Additionally securing the amplifier at the rear
becomes necessary, if the rack case in which the power amplifier has been installed will be transported. Failure to do so may
result in damage to the power amplifier as well as to the rack case. Attach the power amp as shown in the illustration using 4
case nuts and screws. Brackets for securing the power amplifier are available as accessories.
2.5 Ventilation
As with all Electro-Voice power amps with fan cooling, the airflow direction is front-to-rear, obviously because there is more
cold air outside of the rack case than inside. The power amplifier remains cooler and dissipating the developing waste heat in
a specific direction gets easier. In general, setting up or mounting the power amplifier has to be done in a way that fresh air
can enter unhindered at the front and exhausted air can exit at the rear. When installing the power amp in a case or rack
system, attention should be paid to these details to provide sufficient ventilation. Allow for an air duct of at least 60 mm x 330
mm between the rear panel of the power amplifier and the inner wall of the cabinet/rack case. Make sure that the duct reaches
up to the cabinet’s or the rack case’s top ventilation louvers. Leave room of at least 100 mm above the cabinet/rack case for
Device
Voltage
Frequency
Power Consumption
CPS4.5
220-240 V AC / 120 V AC / 100 V AC
50-60 Hz
490 W
CPS4.10
220-240 V AC / 120 V AC / 100 V AC
50-60 Hz
840 W
CPS8.5
220-240 V AC / 120 V AC / 100 V AC
50-60 Hz
930 W
Table 2.1: Operating Voltage
preliminary
