feature the greatest level of protection available. These
units include multiple MOV’s, gas discharge tubes,
fast-blow fuses, and high voltage inductors and
capacitors. This unique combination can safely absorb
and dissipate large spikes from nearby lightning strikes
and other sources (up to 11,000 amps across any
wiring mode – hot-neutral, hot-ground, or neutral-
ground), as well as attenuate audible high frequency
noise. All PRO models feature precise high-inrush
magnetic circuit breakers, virtually eliminating the false
tripping often encountered with large reactive loads
like power amps.
Protection OK Indicator: This LED is normally lit
when the PL-PROD, PL-PRODM, or PM-PRODM’s are
switched on. It monitors the integrity of the protection
devices and reports if the protection is compromised. If
an extremely large spike is encountered that exceeds
the unit’s capacity, the main group of input protectors
will blow an internal fuse, causing the indicator to go
out. If this LED is not lit when the power switch is on,
full protection is not functioning. Spike protection may
still exist, but will have a reduced capacity to absorb
current. If this LED is not lit, please contact the Furman
Service Department.
Ground OK Indicator: This LED is normally on
when the power to the PL-PROD, PL-PRODM, or
PM-PRODM’s outlets are switched on. It monitors the
integrity of the grounding, and reports if the grounding
is compromised. It lights if a reasonably good safety
ground exists. If this LED is not lit when the power is
on, the unit is either improperly grounded, or the AC
source has its Line and Neutral wiring reversed. Unplug
the AC cord and correct the ground or AC service.
Digital Voltmeter: The PL-PROD’s digital voltmeter
continuously measures incoming AC voltages with
extraordinary accuracy (+/- 1VAC). The meter reads
from 45 to 141 volts in 1-volt steps.
Digital Volt / Current Meter and Meter Switch: The
PL-PRODM and PM-PRODM True R.M.S. digital volt /
current meter continuously measures incoming AC
voltages with laboratory accuracy (+/- 1VAC). The
meter reads from 45 to 141 volts in 1-volt steps.
Additionally, when their meter switch is set in the
current mode, it will measure the full AC load
circulating through either the PL-PRODM, or PM-
PRODM, (+/- 0.1Amp). Because of the True RMS
circuitry employed, variable AC line distortions will not
affect the accuracy of either measurement.
NOTE: The PL-PROD, PL-PRODM, and PM-PRODM
do not compensate for high or low line voltage. If you
frequently move your rack to different locations, derive
power from generators, use long extension cords,
travel internationally, or are in an area prone to
brownouts, you may benefit from the use of one of
Furman’s AC Line Voltage Regulators.
Switched Outlet (front panel): This convenience
outlet provides conditioned power when the unit is
plugged in and the circuit breaker is switched to the
ON position.
Circuit Breaker On/Off Switch: This appears to be an
ordinary toggle switch, but in fact is a precision
magnetic circuit breaker. Because its operation is
magnetic, not thermal, it is much more accurate in its
tripping current, yet it will not tripped falsely by the
transient high inrush currents often encountered when
turning on large reactive loads like power amps. Its trip
point is unaffected by ambient temperature. If it trips,
reduce the unit’s load by removing one piece of
equipment, then switch it back to the ON position.
T R O U B L E
S H O O T I N G
G U I D E
The PL-PROD, PL-PRODM, and PM-PRODM’s status
LEDs will inform you of abnormal conditions at a glance:
Symptom:
PROTECTION OK indicator not lit.
Possible Cause:
Protection devices are damaged.
Action Needed:
Factory service.
Symptom:
GROUND OK indicator not lit.
Possible Cause:
Either no building ground, or
reversed Line and Neutral wiring at
the outlet.
Action Needed:
Locate a properly wired, grounded
outlet.
Symptom:
EXTREME VOLTAGE indicator lit.
Possible Cause:
Input voltage is above 140 volts,
causing power to the unit’s outlets to
be shut down. Additionally, if the
voltage is below 90 volts at turn on,
the unit will not allow AC voltage to
reach the outlets.
Action Needed:
Correct the line voltage. Then turn
the unit on. Consider installing a
Furman voltage regulator.
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