Mackie FR800/FR1400/FR2500 FR Series Owner's Manual - Page 11

Owner's Manual General Precautions AC POWER REQUIREMENTS The amplifier's power cord should be plugged into an AC outlet properly configured with the voltage required for your particular model. Be sure the AC outlet can supply enough current to allow full power operation of all the amplifiers plugged into it. The outlet should be a three-prong socket that matches the power cord. WARNING: Bypassing the plug's safety ground pin can be dangerous. Don't do it! If the amplifier should overheat, a thermal switch turns off the power amplifier, allowing the heatsink to cool down. Once the amplifier has cooled to a safe operating temperature, the thermal switch resets and reactivates the amplifier. If this should occur, identify the cause of the problem and take corrective action. For example: • Provide better ventilation • Install a fan in the rack to move more air • Make sure the amplifier is not overloaded with too low of a load impedance or by a short circuit on the speaker line The AC current demand of an amplifier varies depending on several factors, including the load impedance, the crest factor, and the duty cycle of the program material. Under typical conditions reproducing rock music where musical peaks are just below clipping, the amplifiers require the following average currents: FR•800 = 5 A FR•1400 = 7 A FR•2500 =10 A It is recommended that a stiff supply of AC power be used because the amplifier places high current demands on the AC line. The more power that is available on the line, the louder the amplifier will play and the more peak output power will be available for cleaner, punchier bass. If you have more than one amplifier sharing an AC outlet, you should avoid turning them all on at the same time. Rather, sequence them on, one at a time, to prevent popping the circuit breaker (due to in-rush current). THERMAL CONSIDERATIONS The power amplifier is fan cooled. Air is drawn through the rear panel vents, to cool down the amplifier heatsinks, and then expelled through the front panel vents. When installing, be sure to allow sufficient air space around the front and rear of the amplifier for adequate cooling for the heatsinks. Leave at least one rack space above and below, and at least 6 inches behind and in front of the chassis to allow proper ventilation. RACK MOUNTING The FR amplifiers are designed to be mounted in a standard rack. They require two rack spaces (2U = 3.5"). They also require 15.75" depth inside the rack, including the rear support brackets. When designing your rack, put the heavier items at the bottom and the lighter items toward the top. Secure the front panel of the amplifier to the front of the rack using four screws with soft washers to prevent scratching the panel. In addition, because of the weight of the amplifier, you must secure the rear support brackets of the amplifier to the back of the rack. You could use a support rail or shelf across the back of the rack, or angle brackets attached between the rear support rails and the rear rails of the rack. This is recommended for all components mounted in a rack that is going to be moved frequently. MAINTENANCE Usually, your amplifier will not require regular maintenance for normal use. However, you can do several things to keep it in good operating and cosmetic condition. • Testing: Periodically test your system for proper performance. A simple test is to play a CD through it using well-defined, articulate, wide-range program material. Listen to ensure all drivers are working properly and for any evidence of distortion or other extraneous sounds. Test at several volume levels: very low, normal, and high. • Cleaning: Use only a clean dry cloth to dust off and clean the surface. Turn off the power to the amplifier while you do this. Owner's Manual 11