P S - P R O H T - P O W E R CO N D I T I O N E R / S E Q U E N C E R
other units.
The STATUS lines work the same in either
mode. Each reflects the true state of the unit’s
outlets and is affected by both the “memorized”
state and by the key lock switch. A separate
LED must be used to indicate the status of each
PS-PRO HT.
To address the unusual (hopefully rare) instance
when several PS-PRO HTs in parallel fall out of
sync, resulting in some units turning on and oth-
ers turning off when a remote button is pushed,
the remote signal line has a special feature:
Holding the REM line high for at least 4 seconds
will force all units to the OFF state, putting them
back in sync. This is the only way to re-sync units
other than disconnecting AC power to all units.
Remember — turning any key lock switch to OFF
does not affect the stored state, even though it
will temporarily turn the output of that unit off. If
it is turned back to REM, the PS-PRO HT will
sequence back to ON because the stored state
is still ON.
The above covers the case of multiple units in
parallel (all sequences initiate simultaneously).
See “AC Relay Accessory PS-REL” below for a
discussion of wiring multiple units in series.
STATUS Terminal
The STATUS terminal is an output that may be
used to illuminate an LED at the remote location
indicating that the power is available at the PS-
PRO HT’s outlets. If it is high (+5V), the unit is ON
(or at least in the process of sequencing ON); if
low, the unit is OFF (or sequencing OFF). Simply
connect the indicator LED between STATUS
and ground (do not use a series resistor). If the
LED does not light when the switch is in the ON
position check the polarity and reverse the LED
leads if needed.
Effects of Lightning
8
Lightning is a natural phenomenon of over-
whelming force that represents the most dif-
ficult circumstance faced by a power protection
product. The degree of protection a PS-PRO
HT 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 PS-PRO HT will absorb the excess voltage
invisibly and harmlessly. However, if lightning
strikes the actual building where the PS-PRO HT
is installed (or somewhere very nearby), some
damage may be unavoidable due to the ex-
tremely high voltage and current present. If this
does occur, most likely damage will be limited to
the PS-PRO HT itself and will affect only certain
spike suppression components (called varistors
or MOV’s.) In this “suicide” mode, the PS-PRO
HT 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
Electrical Code.
Any PS-PRO HT known to have taken a direct
lightning hit should be checked by a qualified
technician or the Furman factory to determine
of the MOV’s need replacement. (If the PS-PRO
HT’s PROTECTION OK indicator is not lit, there
is definitely some damage. Some spike suppres-
sion capability may still be available by MOV
Bank #2, but there is no guarantee of this.)
For optimum protection, you should not rely ex-
clusively on the PS-PRO HT to protect 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 an electri-
cal contractor to have one installed.
