IT-REFERENCE 15 OWNER’S MANUAL
be left with its power engaged permanently
at a cost of pennies per month. This is an
added benefi t, as many audio/videophiles
fi nd performance improves signifi cantly when
leaving low-powered components permanently
charged (turned on). In fact, this is true of
the IT- Reference 15. Though it will function
fl awlessly right from its shipping carton, the
performance of its circuit parts will improve
after approximately two weeks of continuous
use or “break-in.”
Ground Fault Interrupter (GFCI)
The IT- Reference 15’s “Discrete Symmetrical
Filtered AC outlets” incorporate a balanced
AC power output, whereby both the neutral
and positive leads of the AC cable run at 60
Volts AC in opposing polarity, referenced to
ground (0 Volts AC). This is but one of the
IT- Reference 15’s advantages over other AC-
fi lter/protection designs.
Though virtually all domestically produced
electronic equipment is designed to detect
electrical shorts and other potentially
dangerous equipment problems in the
Line lead referenced to its Neutral, this is
inadequate when power is “balanced.” With
the IT-Reference 15’s balanced outlets,
both neutral and positive legs contain 60
VAC relative to their Ground tab. This is
not a problem or safety hazard, unless
there is a defect in either the IT- Reference
15’s transformer, or the power supply of a
connected component. In this instance,
we need to assure that safety is always
maintained. The solution is our GFCI (ground
fault circuit interrupter).
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The Furman GFCI detects any imbalance in the
current fl owing in the two hot legs. The missing
current is presumed to be fl owing 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 will trip the outlets internal
breaker, and the Duplex AC outlet will no
longer supply Ac power of any sort. To restore
operation, correct the fault, press the reset tab
located between the two balanced AC outlets. 5
mA of current is enough to cause the GFCI to
trip; to troubleshoot this type of problem, start
with nothing connected to the IT-Reference 15’s
balanced power outlets. Then, add each piece
of equipment until the GFCI trips. Contact the
manufacturer of the suspect unit for possible
solutions.
AC Transient Voltage Surge
Suppression and Extreme
Voltage Shutdown
Extreme Voltage Shutdown Indicator:
This LED is normally off. It monitors AC wiring
faults – for example, accidental connection to an
open neutral from a 208 or 240VAC feed (this is a
common occurrence if the 15 Amp outlet source
is not a dedicated line, but instead has been
wired with a daisy-chained neutral from a homes
breaker box). The Series Multi-Stage Protection
Plus (SMP+) 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 these
units, the Extreme Voltage indicator LED will light
if the input voltage is above the extreme voltage
cutoff, and power will not be applied to the unit’s
