Furman P-240 IT, Руководство пользователя

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P-2400 IT OWNER’S MANUAL
small magnetic field. Therefore, we recommend that it not be positioned adjacent to sensitive, low level signal processors, especially
mic preamps, mixers, tape recorders, etc. Power amps may be more suitable “rack neighbors.”
The maximum benefit derived from balanced power is when it powers ALL equipment in an installation. Therefore, try to position
the P-2400 IT in a central location so its power can be easily distributed everywhere it’s needed. If the total power consumption of
all equipment exceeds 20 amps at 120 volts, delete high level or mechanical devices first (such as power amps, motors). If possible,
physically isolate any equipment that has to be powered with conventional power through a different circuit, and route AC cords away
from all other cabling. The balanced power produced by the P-2400 IT is restricted to use with electronic equipment only. Balanced
power may not be used for lighting equipment, and access must be limited to use by qualified personnel only.
Rear Rack Mounting:
If you are installing the P-2400 IT in a rack that has rear as well as front mounting rails, you may easily secure it to the rear of your rack.
Simply remove the securing screws from the side and front portions of the P-2400 IT’s adjustable rear rack ear and reinforcement side
plate (located on either chassis side), reverse it and re-attach to the P-2400 IT chassis. (See Figure 1.a, page 12)
OPERATION
Switchable Voltage and True RMS Current Meter:
Furman’s laboratory precision AC digital voltmeter continually measures incoming voltages within a typical tolerance of +/-1.5VAC. It
should be noted that the voltage reading is incoming.
Furman’s laboratory precision True RMS digital current meter continually measures the total circuit AC load within a typical tolerance
of +/- 0.5 amp. Because these meters feature true RMS technology, the current readings are accurate regardless of load conditions
(capacitive, inductive, or resistive). To switch between voltage and current, press the button labeled “Line Voltage/Current”. Hold this
button down for two seconds to dim the brightness of the display.
Voltage Range Indicator:
This indicator is located in the lower left corner of the digital volt / amp meter lens assembly. When AC voltage is within 5 volts (+/-)
of a nominal 120VAC source, this tri-color indicator will be green (optimal). However, if the voltage is between 110 to 114VAC, or be-
tween 126 to 130VAC, the indicator will turn amber (caution - not optimal). If the incoming voltage is in an extreme range (below 110
or above 130), the indicator will turn red. This range is far from optimal, and may be potentially damaging to some equipment.
Ground Fault Interrupter (GFCI):
The Ground Fault Circuit Interrupter (GFCI) on the P-2400 IT’s rear panel is a special kind of circuit breaker that detects an imbalance
in the current flowing into the two hot legs. The “missing” current is presumed to be flowing through the ground conductor (the round
pin on an AC outlet).
Ground current often indicates a dangerous partial or full short circuit. If an imbalance is detected, the GFCI trips and cuts off power
not only to itself, but to all the P-2400 IT outlets. If this occurs, the button on the GFCI marked “R” (Reset) will pop out. To restore
operation, correct the fault and push the button in. You may test the proper operation of the GFCI at any time by simulating a ground
fault by pushing the button marked “T” (Test). If the GFCI is working properly, this will cause the “R” button to pop out and cut off
power. You can restore operation after a test by pushing in the “R” button.
Ground Lift Switch:
Ground loops are fairly common in many installations because AC cords with safety grounds are rarely connected to a single low-resis-
tance bus bar. When there is a significant difference in voltage between a source component’s neutral and ground and a load compo-
nent’s neutral and ground, the buzz and hum associated with this type of ground current noise (or loop) may occur. Additionally, many
AC noise contaminants may be present on the AC ground wire. For these reasons, Furman’s P-2400 IT contains a Ground Lift Switch.
This switch floats the output ground, eliminating ground noise and also, in many instances, the hum and buzz associated with ground
loops. The P-2400 IT’s GFCI protection circuit assures that even when utilizing the power conditioner in this mode, operation is safe
and secure. In fact, even if a connected component has a catastrophic failure, less than 5 milliamps current imbalance from line to
ground or neutral to ground will instantly disconnect the voltage output from the P-2400 IT. This is far safer than any conventional 120
VAC outlet and it has numerous noise reducing advantages.
However, ground wiring in any studio, broadcast or club environment can be complex. Because all 14 outlets of the P-2400 IT are in
parallel, it is still possible to have a ground loop if the two offending products are simultaneously connected to a single P-2400 IT. Use
of multiple P-2400 IT’s may be necessary in extreme cases. Also, for studio and broadcast use, separating all digital processing products
from all analog devices is highly recommended and can be accomplished by separating these components into the two isolated banks,
or for the very best performance, using two P-2400 IT’s.