User manual FURMAN AR2330D

[. . . ] There are no controls except an on-off breaker switch. Limitations: The AR-2330D is for use with AC voltage only. DC voltages should never be applied to it. Also, it does not change or regulate line frequency. [. . . ] If this unlikely condition occurs, please remove power from the unit first. Design The AR-2330D uses a design based on an eight-tap toroidal autoformer. The toroidal design assures minimal leakage of stray magnetic fields, and, because of its high efficiency, a very compact size for its rating. The Voltage Regulator's circuitry monitors the incoming line voltage with each cycle, comparing it to an extremely precise voltage reference, accurate to ±0. 15%. If a voltage fluctuation requires that a different tap be selected, the new tap is electronically switched exactly at the zero-crossing, to avoid distorting the AC waveform. If necessary, it can switch taps as often as once each cycle. Some commercial voltage regulators using multiple-tapped transformers switch taps at uncontrolled times, thereby creating voltage spikes and clicks that can leak into the audio!Hysteresis in the switching circuits avoids "chatter" or unnecessary switching back and forth between adjacent taps. And un like voltage regulators that em ploy ferro-res o nant trans form ers, the Fur man AR-Series is not sensitive to small errors in line frequency, making them ideal for use with generators. Fuses and Circuit Breakers There are three fuses and one fast-acting magnetic circuit breaker in the AR-2330D. A precision 30 amp magnetic circuit breaker is used as the on/off switch. If the input to the unit exceeds 30 amps, the breaker will trip. Be sure to reduce your load before re-powering the unit, or it will likely trip again. Refer to the previous section "Maximum Load" if you are uncertain why the breaker is tripping, or want to understand the relationship between input voltage and current vs. A fast-blow 250 mA amp fuse is located inside the unit, as previously mentioned. To replace it, the unit must be completely disconnected from all power and removed from its rack. The six hex head screws and one Allen head screw holding the top cover must be removed. A Fast Blow 1 amp fuse protects a low current auxiliary winding on the large transformer. Supply Cable Wiring The AR-2330D's rear panel provides a NEMA L14-30P male inlet connector; a NEMA L14-30 cord mounted female connector is included with the unit. Please refer to the "Rear View" wiring diagram at right. Wire the two hot leads (black) to X and Y (black, and white or red), and the equipment ground (green) to G. It is essential that all equipment powered by an AR-2330D be properly grounded!Never cut off the power cord ground pin or use a "cheater" adaptor on any of your equipment! Input Voltage Monitoring The row of ten LED's at the top left of the front panel make up a meter that indicates INPUT VOLTAGE. There are two red LED's at the endpoints. When lit, they indicate that the input voltage may be above or below the point where it can be restored to the selected nominal output voltage (though it may still be restored to a usable level) but is not high or low enough to cause an extreme voltage shutdown. Installation The AR-2330D is designed for mounting in a standard 19-inch rack. [. . . ] They are an unavoidable component of electric power. They are caused unpredictably by electric motors switching on or off (on the premises or outside), utility company maintenance operations, nearby lightning strikes, and other factors. Spikes (also called surges or transients) are absorbed by special components called MOV's in the ARseries to provide safe voltage levels to protect your equipment. RFI/EMI INTERFERENCE: Noise from RFI (Radio Frequency Interference) or EMI (Electro Magnetic Interference) involves lower voltages and less energy than is found in spikes, but it is continuous rather than transient in nature. [. . . ]