Furman Sound PS-8R, PS-8RE, PS-8, PS-8E User Manual

Petaluma, California 94954-6919 USA

Phone: [phone] • Fax: [phone]

Power Sequencer

MODELS PS-8, PS-8R, PS-8E and PS-8RE

Instruction Sheet

Furman Sound, Inc.

1997 South McDowell Blvd.

www.furmansound.com

E-mail: [e-mail]

PS-8 Features

● Power-up in three delayed outlet groups

● Power-down reverses sequence

● Triple-mode varistor spike and surge suppression

● RFI filtering with multi-stage pi filter

● Power Status LED’s indicate which outlet groups have power

● Mains Wiring indicators monitor wiring integrity, show Normal

and five kinds of faults

● Rated 15 amps

● Remote option allows turn-on and turn-off at a distance

simply by connecting a momentary or maintained-contact
switch (and LED if desired)

● Multiple units may be linked to handle higher currents and/or
more than three delay groups

● Three pairs of switched outlets on rear panel

● Three unswitched outlets (one front, two rear)

● Circuit breaker

● Ten foot heavy duty A.C. cord

● Three year limited warranty

Introduction

Congratulations on your purchase of a Furman PS-8 Power

Sequencer, a well-designed, reliable, and simple to use product

that will help you avoid many headaches involved in installing a
rack full of complex equipment.

The PS-8 Power Sequencer is needed whenever various
kinds of equipment must be powered up or down in groups, rather
than all simultaneously. In audio systems, sequenced po wering is
often necessary to allow turn-on transients from low level
amplifiers and processors to settle down before any power amps
are turned on, because simultaneous powering would result in a
loud, annoying, and potentially destructive “pop” reaching the
speakers. And 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 excessiv e inrush currents that cause circuit break ers to
trip even though the steady-state currents are not excessive.

Power Sequencing Features

Using the PS-8 is a simple and inexpensive way to apply and
remove power in a controlled, repeatable, foolproof 3-step
sequence. It is ideal when large installations must be switched by
inexperienced personnel.

The PS-8 provides three outlet pairs labeled Delay 1, Delay 2,
and Delay 3, that receive power approximately 1/2, 5, and 10
seconds, respectively , after the front panel s witch is thrown to “ON. ”
When thrown to “OFF,” the sequence is reversed, with Delay 3
losing power after approximately 1/2 second, Delay 2 after 5
seconds, and Delay 1 after 10 seconds. See the rear panel
illustration on the next page. The turn-on delay intervals are factory
preset at these durations, but may be altered by means of an
internal trimpot adjustment (see “Adjusting the Delay Intervals”
below for details). In addition to the delayed outlets, a single front
panel outlet and a rear panel pair are unswitched. Po wer is available
at the unswitched outlets regardless of the position of the front
panel (or remote) switch. All rear panel outlets are standard 120V,
15A duplex types. Isolated-ground “Super Spec” outlets are
available by special order.

In the event of a power out, of course all equipment plugged
into a PS-8 will lose power simultaneously. Howev er, when power
is restored, the delayed outlet groups will again turn on in the
usual delayed sequence.

We recommend that power amps receive power last —
plug them all into Delay 3 or divide them into two groups and plug
one group into Delay 2 and the other into Delay 3. Low le vel equip­ment such as mixers and signal 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-8 is 15 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 15
amps at any time, the circuit breaker will trip, cutting off power to
your rack. If this occurs, you must reduce the load by unplugging
one or more units from the PS-8. Then push the white button on

5-9927

960032-1051

Rear Panel Outlets

120 VAC

60 HZ

15A

15

A
M
P

UNSWITCHED DELAY 1 DELAY 2

CAUTION!

RISK OF ELECTRIC

SHOCK. DO NOT

OPEN. REFER
SERVICING TO

QUALIFIED SERVICE

PERSONNEL.
TO REDUCE THE
RISK OF FIRE OR

ELECTRIC SHOCK

DO NOT EXPOSE

THIS EQUIPMENT TO

RAIN AND MOISTURE.

Model PS-8R is shown. Model PS-8 is similar except the barrier terminal strip at right is not present.

120 VAC

60 HZ

MAX

LOAD

15A

AVIS:

RISQUE DE CHOC
ELECTRIQUE—NE

PAS OUVRIR

®

LISTED

7Z37

PROFESSIONAL

AUDIO EQUIPMENT

®

DELAY 3

CLASS 1

WIRING

+12V

STATUS

REM IN

GND

ON POWER UP:

This pair of outlets
plus the one on the
front panel are on
regardless of the

This pair of outlets
comes on approx.
1/2 second after the
switch is turned on.

This pair of outlets
comes on approx. 5
seconds after the
switch is turned on.

This pair of outlets
comes on approx. 10
seconds after the
switch is turned on.

switch position.

ON POWER DOWN:

Note: “The switch” referred to in this chart is either the front panel switch or, if used, the remote switch connected to the terminal strip of a PS-8R.

the circuit breaker (on the rear panel) down and in to reset it.

Although 15 amps is an absolute limit, the PS-8’s power
sequencing capability will allow you to come as close as possible
to using the full 15 amps, because the risk of tripping the breaker
is greatly reduced. This is because the PS-8 handles large but
temporary inrush currents in stages, rather than simultaneously,
allowing each stage to settle to its steady-state current draw
before the next stage is powered.

Same as above.

This pair of outlets
goes off approx. 10
seconds after the
switch is turned off.

Mains Wiring Fault Analyzer

in the AC mains wiring. Two green and one red neon indicators
light in a specific pattern for normal wiring and in different
patterns for various faults. When the AC wiring is correct, both
green indicators will be lit, but not the red indicator. If any other
pattern of indicators is lit, a fault is present. The chart next to the
indicators identifies its exact nature. Since any wiring fault

This pair of outlets
goes off approx. 5
seconds after the
switch is turned off.

This pair of outlets
goes off approx. 1/2
second after the
switch is turned off.

The PS-8 also assists in analyzing any faults that may occur

presents a potentially serious safety hazard, the assistance of a
qualified electrician should be obtained in correcting the problem.

Power Conditioning Features

The PS-8 offers all basic power conditioning f eatures besides
its sequencing capability. It provides varistor spike and surge
protection across all three modes (line to neutral, line to ground,
and neutral to ground), responding in nanoseconds to clamp
excessive transient voltages to safe levels. There is also a
sophisticated multi-stage filter for blocking radio frequency line
noise. The filter works to prevent noise from fluorescent lights,
certain dimmers, radio transmitters, and similar sources of
“electronic pollution” from leaking from the AC line into sensitive
audio, video, or computer circuits. Clean, filtered power is
provided at all 9 outlets, even the unswitched ones.

Despite its many protective features , you should be aware that
the PS-8 does not compensate if the AC line voltage itself is high
or low (i.e., it does not compensate for brownout conditions). If
you frequently move y our rac k to diff erent locations , derive pow er
from generators, use long extension cords, travel internationally,
or are in an area particularly prone to brownouts, you may benefit
from the use of one of Furman’s AC Line Voltage Regulators in
addition to the PS-8. If you do use a v oltage regulator , run the ra w
power line into the regulator first so that the PS-8 receives a
stabilized voltage to distribute.

Adjusting the Delay Interval

The delay interval (the time between the turn-on or turn-off of
outlets 1 and 2, or 2 and 3 — not 1 and 3) is factory preset at
approximately 5 seconds. It is possible to lengthen or shorten the
delay interval by making an internal adjustment to the PS-8.
However, due to the risk of electric shock, this procedure should
only be done by a qualified technician.

Unplug the PS-8 and remove its top cover by unscrewing the
four screws that secure it. The delay adjustment is Trimpot VR1,
located on the printed circuit board near the front left corner. It is
the only trimpot on the board. It is equipped with a thumbwheel f or
easy adjustment. The range of adjustment of the delay
interval is from a minimum of about 1 second to a maximum of
about 7 seconds.

220/240V Versions (Units with E Suffix Only)

Models PS-8E and PS-8RE are intended for use in countries
with nominal 220 to 240 volt AC lines. They are identical
to the PS-8 and PS-8R except their rear panel outlets are the
internationally-accepted IEC-320 connectors. They are rated at
10 amps.