Output Current Monitoring - Furman AR-1230 Owner's Manual

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precisely, you may want to use a Furman PL-PLUS
Power Conditioner and Light Module in conjunction
with it. The PL-PLUS is the perfect complement to
a Furman Voltage Regulator to assist in rack power
distribution. It offers a 20-LED bar-graph line voltage
meter to monitor the incoming line (the Voltage Reg-
ulator output), twin slide-out, swiveling lights with a
dimmer control for equipment illumination, and eight
AC outlets with their own spike/surge protection and
RFI fi ltering.
DEFINITIONS
VOLTAGE REGULATION: The AC line voltage is a
number indicating the nominal electrical potential that
has been adopted in a region for powering electrical
equipment of all kinds. In most of North America it is
117-120 volts AC; in Japan, 100 volts; and in many
other countries 220, 230, or 240V. The actual voltage
can fall below or rise above this nominal level due to
brownouts, power cutbacks, use of substandard wiring,
and other causes. These deviations can cause poor
performance or malfunction. A regulator is a device
which, through use of a transformer, corrects the volt-
age deviation by stepping it up or down so that it is as
close as possible to the nominal level.
SPIKE: A pulse of energy on the power line. Spikes
can have voltages as high as 6000 volts. Though
they are usually of very short duration, the energy
they contain can be considerable, enough to dam-
age sensitive solid-state components in audio and
computer equipment. Spikes can also foul switch
contacts and degrade wiring insulation. They are
an unavoidable component of electric power. They
are caused unpredictably by electric motors switch-
ing 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 AR-series to provide safe volt-
age 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
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A C L I N E V O L T A G E R E G U L A T O R
than is found in spikes, but it is continuous rather than
transient in nature. It is not likely to cause physical
damage, but it can certainly be annoying, producing
static in audio circuits, "snow" on video screens, or
garbled data in computers. Noise can be introduced
into AC lines by nearby radio transmitters, certain
kinds of lighting, electric motors, and others. Because
noise occurs at higher frequencies than the 50 or 60
Hz AC line, it can be effectively reduced through use
of low-pass fi ltering.

OUTPUT CURRENT MONITORING

The AR-1230's ammeter reads AC current from 0
to 30 amps, in 3-amp steps. Currents above the 30
amp limit read red, with yellow indicating a warning
zone. Please keep in mind that the ammeter may
not read at all if the total load connected is less
than 2 amps (240 watts). This is a likely occurrence
if only relatively low power, signal processing-type
equipment is connected. With the master switch
off, the ammeter can still read, but will only do so if
equipment drawing at least 2 amps is connected to
the unswitched outlet.
The ammeter is capable of giving a reliable indica-
tion of current drawn by all kinds of equipment,
thanks to its true-RMS-reading circuitry. This means
that loads like power amplifi ers, which are primarily
capacitive and inductive, will read as accurately as
purely resistive loads like heaters. Ammeters that
respond only to average AC current may vary widely
from RMS reading meters.
DESIGN
The AR-1230 uses a design based on an eight-tap
toroidal autoformer. The toroidal design assures
minimal leakage of stray magnetic fi elds, and, be-
cause of its high effi ciency, a very compact size for
its rating. The Voltage Regulator's circuitry monitors
the incoming line voltage with each cycle, compar-
ing it to an extremely precise voltage reference,
accurate to ±0.15%. If a voltage fl uctuation requires
that a different tap be selected, the new tap is
electronically switched exactly at the zero-crossing,