Operation, Cooling System and Requirements

Operation

Connecting Power / Circuit Size Requirements.

PL Series amplifier power requirements are rated at:

a)“idle”

b)1/8th power (“typical” music conditions)

c)1/3rd power (“continuous” music conditions) d.) maximum rated power (circuit breaker limited).

The maximum power current draw rating is limited only by the front panel circuit breaker. Consult the spec- ifications in the Appendices section for figures on the current that each amplifier will demand.

Make sure the mains voltage is correct and is the same as that printed on the rear of the amplifier. Damage caused by connecting the amplifier to improper AC voltage is not covered by any warranty. Unless other- wise specified when ordered, Crest amplifiers shipped to customers are configured as follows:

North America	-	120VAC / 60Hz
Europe	-	230VAC / 50Hz
Asia	-	220VAC / 50Hz
Australasia	-	240VAC / 50Hz
South America	-	120VAC / 60Hz or 220VAC / 50Hz
Japan	-	100VAC / 50Hz

NOTE: Always turn off and disconnect the amplifier from mains voltage before making audio connections. Also, as an extra precaution, have the attenuators turned down during power-up.

Cooling System and Requirements.

PL Series amplifiers use a twin-tunnel forced-air cooling system to maintain a low, even operating tempera- ture. Drawn in by dual 45 cubic feet-per-minute (CFM) fans on the rear panel, air flows through the cooling fins of the channel heat sinks (dissipating power transistor heat), then exhausts through the front panel slots. The “intelligent” variable-speed DC fans are controlled by heat sink temperature-sensing circuits. When the amplifier is turned on, the fans briefly “rev up,” then slow to an idle; this indicates that the temperature sensing circuits are operating normally. The fan speed increases only as required by heat sink temperatures, keeping fan noise to a minimum. Under extreme thermal load, the fans will force a very large volume of air through the heat sinks. If either heat sink surpasses the maximum allowed temperature, the sensing circuit will open the output relay, disconnecting the load from that channel. If the power transformer overheats, another sensing circuit opens both channel output relays until the transformer cools to a safe temperature.

IMPORTANT: To ensure optimum cooling, periodically clean the amplifier fan filters (removable without tools). Also make certain that there is enough space around the front of the amplifier to allow the cooling air to escape. If the amplifier is rack-mounted, do not use doors or covers on the front of the rack; the exhaust air must flow out without resistance. If the amplifiers are to be housed in racks with closed backs, allow at least one (1) standard rack space of opening in the front of the rack for every four amplifiers.

Crest Audio PL Series Power Amplifiers	Page 9
Models PL3301, PL4601, PL6001, PL7001, PL8001, PL9001