Furman P-2300 Manual Del Propietário página 7

Extreme Voltage Shutdown Indicator:
The Extreme Voltage LED indicator is normally off. It is located within the meter lens assembly directly above the blue voltage / cur-
rent LED's, though during normal use it will NOT be visible.
The Extreme Voltage Shutdown (EVS) indicator monitors a hazard common in the entertainment, remote broadcast, and AV contrac-
tor industries : wiring faults. For example, an accidental connection to 300+ VAC where 220 to 240VAC is expected, or an open
series neutral from a multi-phase electrical service. The Furman EVS circuit senses voltages that are so high that operation would be
impossible and shuts the power down before damage can occur.
Upon initially applying power to the P-2300 IT E, the Extreme Voltage indicator will illuminate to a bright red if the input voltage is
above the extreme voltage cutoff. When this occurs, power will not be applied to the outlets. If the unit has been operating with
an acceptable input voltage ,and subsequently that voltage exceeds 275V, it will shut off power to the outlets and the Extreme Volt-
age LED will light.
NOTE: If the mains power is above the high cutoff voltage and has caused the Extreme Voltage circuit to remove power from the
outlets, it cannot restore power without the operator manually turning the unit off, then on again. Avoid turning the unit back on,
without first checking the source of the problem and perhaps changing the AC source.
Protection OK Indicator:
Although the Furman SMP circuit assures virtually maintenance free protection from transient voltage spikes and surges, nature has
a way of occasionally creating electrical forces that are beyond the capabilities of ANY TVSS device to absorb without some degree
of damage (such as a direct lightning hit in an outdoor application). In the rare instance that this occurs, the green "Protection OK"
LED indicator (located at the bottom right of the meter display), will dim. If this happens, some level of protection from voltage
surges will remain, but the Furman's clamping voltage rating will be compromised. The unit must be returned to Furman Sound.
USB Charger:
The Furman P-2300 IT E's USB charger provides an easy way to recharge many popular electronic accessories as well as cellular
communication devices by simply plugging the re-charge cord into the front panel socket. Please note: because there are currently
many standards for USB, some devices may not be compatible with our charger.
Isolated Outlet Banks:
The Furman P-2300 IT E features twelve rear-panel outlets in 2 isolated banks. If you are connecting digital and analog equipment to
the P-2300 IT E, it is recommended to connect the analog equipment to "Bank A" and digital equipment to "Bank B" (or vice-versa)
to minimize electrical crosstalk.
How Balanced AC Power Works:
In much the same way that balanced audio lines can reduce the pickup of hum and other types of electromagnetic interference
(EMI), the use of balanced AC power lines in sensitive audio, video, or computer installations can make an enormous difference in
system noise and signal integrity. But power distribution throughout the world, unfortunately, is not balanced.
The distribution standards currently in use were derived from practices established over a century ago when electric power use was
limited to lighting and motors, long before any AC noise sensitive applications existed. The emphasis then was on convenience and
safety, but not noise cancellation.
The result was a three-wire distribution scheme in which 230V branch circuits have a hot wire and a neutral wire, with the neutral
tied to a third wire connected for safety to an earth ground. The third wire does not carry any current unless there is a fault. This
unbalanced scheme can create hum in audio circuits for two main reasons. First, the current flowing in the hot wire induces hum
in any other nearby wires, which may carry vulnerable low-level audio or video signals. Second, because the impedance of chassis
and cable shielding to ground is always greater than zero ohms, ground current flowing from power supply capacitors and from EMI
pickup causes a voltage drop at 50 Hz and its harmonics. This low level noise becomes part of the audio signal.
With a center-tapped isolation transformer, the AC power feeding a studio can be balanced at its source. The current-carrying wires
then are no longer "hot" (230V) and "neutral" (0V), but two 115V lines of opposite polarity (referenced to ground connected to the
center tap), whose difference is 230V.
This type of power, when run around a room, does not induce hum into nearby audio wiring because the two conductors induce
equal and opposite voltages that cancel each other. Similarly, ground currents are all but eliminated by the same common-mode
cancellation effect. No longer is it necessary to adopt cumbersome and expensive star-ground systems or use massive bus bars or
heavy ground rods.
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