Furman Sound PM-PRO-E - Manual (Page 9)

PM-PRO POWER CONDITIONER/MONITOR 9
Symptom:
Possible Cause:
Action Needed:
Symptom:
Possible Cause:
Action Needed:
Symptom:
Possible Cause:
Action Needed:
Symptom:
Possible Cause:
Action Needed:
PROTECTION OK Indicator not lit.
Protection devices are damaged.
Factory Service.
Ground OK Indicator not lit.
No building ground, bad outlet.
Locate good ground, run ground wire.
Flashing voltmeter display.
Input voltage is marginally high or marginally low.
Correct line voltage. Consider installing a Furman voltage
regulator.
EXTREME VOLTAGE Indicator is flashing.
Input voltage is extremely high or extremely low, causing power
to the PM-PRO's outlets to be shut down.
Correct line voltage. Consider installing a Furman voltage
regulator.
Effects of Lightning
Lightning is a natural phenomenon of overwhelming force that represents the
most difficult circumstance faced by a power protection product. The degree of
protection a PM-PRO can offer depends on the intensity of the strike. If lightning
strikes a distant power line and causes a relatively small disturbance to reach your
location, the spike suppressors in the PM-PRO will absorb the excess voltage in-
visibly and harmlessly. However, if lightning strikes the actual building where the
PM-PRO is installed (or somewhere very nearby), some damage may be unavoid-
able due to the extremely high voltage and current present. If this does occur, most
likely damage will be limited to the PM-PRO itself and will affect only certain spike
suppression components (called varistors or MOV's.) In this "suicide" mode, the
PM-PRO may sustain minor damage but generally will protect all equipment plugged
into it from much more serious and costly damage as long as that equipment is
properly grounded. Proper grounding requires the use of three-prong AC cords,
and that the building's outlets are actually grounded to earth as specified by the
National Electric Code.
Any PM-PRO known to have taken a direct lightning hit should be checked by a
qualified technician or the Furman factory to determine whether the MOV's need
replacement. (If the PROTECTION OK indicator is not lit, there is definitely some
damage. Some spike suppression capability may still be available by MOV Bank
#2, but there is no guarantee of this.)
For optimum protection, you should not rely exclusively on the PM-PRO to pro-
tect against a direct lightning hit. The first line of defense against lightning should
be a lightning arrestor installed on your building's electrical service entrance. If your
building does not have one, contact your local power company or a contractor to
have one installed.