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
ing, and potentially destructive “pop” reaching
the speakers.
In any large system whose components present
an inductive load to the AC line (including electric
motors, power supplies, and power amplifiers
of all kinds), sequenced powering can avoid
excessive inrush currents that can cause circuit
breakers to trip even though the steady-state
currents are not excessive. Power sequencing
is particularly suited to applications where large
installations must be switched by inexperienced
personnel.
The PS-PRO HT is controlled by a front panel
key-operated switch to provide security from
non-authorized users tampering with the system.
The switch has three positions: OFF, REM, and
ON, allowing for local or remote control. With
remote control, one or more PS-PRO HT’s may
be installed in remote locations with on/off con-
trol and LED monitoring via low-voltage control
wires. The PS-PRO HT interfaces with computer
touch screen systems as well.
Besides its power sequencing capabilities, the
PS-PRO HT contains many other conditioning
and protection features. Both aspects of its func-
tioning will be discussed in the next sections.
The PS-PRO HT rear panel provides one un-
switched outlet pair and three switched outlet
pairs. The switched outlet pairs are labeled
Delay 1, Delay 2, and Delay 3. (The other pair of
outlets on the rear panel and an additional single
outlet on the front panel are unswitched.)
Here’s how the PS-PRO HT works: When an
ON sequence is initiated, power is immediately
applied to the Delay 1 outlets. Power is then
applied to Delay 2 and Delay 3 outlets per the
1-60 second total delay setting you choose with
the front panel Delay Adjust control.
The screwdriver-settable Delay Adjust controls
the total delay time between the Delay 2 and
Delay 3 outlets. For example, if the Delay Adjust
control is set to 30 seconds, Delay 1 outlets will
go on immediately, Delay 2 outlets will receive
power 15 seconds after Delay 1 outlets, and
Delay 3 outlets will receive power 15 seconds
after Delay 2 outlets. Therefore the total delay
time is 30 seconds.
The order is reversed on an OFF sequence. For
example, when an OFF sequence is initiated and
the Delay Adjust control is set at 60 seconds,
Delay 3 outlets lose power immediately, Delay 2
outlets lose power 30 seconds later and Delay 1
outlets lose power 30 seconds after the Delay 2
outlets have been shut off. The total delay time
is 60 seconds.
In the event of a power out, of course all equip-
ment plugged into a PS-PRO HT will lose power
simultaneously. However, when power is re-
stored, the delayed outlet groups will again turn
on in the usual delayed sequence (Remains off
in Momentary Mode).
Installation Recommendations: In home theater
installations, we recommend that
power amps or
receivers be powered last — plug them all into
Delay 3 or divide them into two groups and plug
one group through Delay 2 and the other through
Delay 3. Low level equipment such as video and
audio processors should use Delay 1. Equipment
incorporating clocks or timers such as VCR’s, or
equipment that must respond to wireless remote
actuation, should use the unswitched outlets.
We suggest keeping the front panel unswitched
outlet free for equipment that is only in use
temporarily.
The overall capacity of the PS-PRO HT is 20
amps. This refers to the combined steady-state
current drawn by all devices plugged into all of
its nine outlets. If this combined current level
exceeds 20 amps at any time, the circuit breaker
will trip, cutting off power to your rack. If this oc-
curs, you must reduce the load by unplugging
one or more units from the PS-PRO HT. Then
push the white button on the circuit breaker (on
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