Furman Sound Power Supply PS 8 User Manual

Furman Sound, Inc.

1997 South McDowell Blvd.

Petaluma, California 94954-6919 USA

Phone: 707-763-1010 • Fax: 707-763-1310

www.furmansound.com

E-mail: [email protected]

Power Sequencer

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

Instruction Sheet

PS-8 ꢀeatures

Power Sequencing ꢀeatures

● Power-up in three delayed outlet groups

● Power-down reverses sequence

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.

● 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

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 switch 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.Power 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.

● 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

In the event of a power out, of course all equipment plugged

into a PS-8 will lose power simultaneously. However, when power

is restored, the delayed outlet groups will again turn on in the

usual delayed sequence.

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.

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 level equip-

ment 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

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 powering 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 excessive inrush currents that cause circuit breakers to

trip even though the steady-state currents are not excessive.

5-9927

960032-1051

Remote Switching (Units with “R” Suffix Only*)

Model PS-8R and PS-8RE differ from the corresponding

models without the “R” suffix in the addition of a barrier terminal

strip on the rear panel that allows a switch to be connected to turn

the unit on and off at a distance, and also in the START ON-OFF

SEQUENCE pushbutton on the front panel.

In the most basic configuration, only two Class 1 wires and an

SPST switch are needed to initiate an ON or OFF sequence.The

switch may be either a momentary or maintained-contact type. If

a third wire is used, an LED may also be installed at the remote

end to indicate that the power is on.

When first plugged in (or after power is lost and reapplied for

any reason) the "memory" state is OFF. This means the unit will

be OFF even if the front panel on/off rocker switch is on. It will stay

off until sequenced on by a momentary connection of the REM IN

terminal to +12V. The sequence starts on the rising edge of the

signal.

The front panel START ON-OFF SEQUENCE switch is in par-

allel with, and functionally equivalent to, one or more remote mo-

mentary switches connected to the barrier strip in the rear.

The “memory” is independent of the front panel on/off rocker

switch. This means that even if the unit is sequenced OFF by the

rocker switch on the front panel, when the rocker switch is turned

back on the unit will sequence back on — it will not be necessary

to push the START ON-OFF SEQUENCE button again. The unit

“remembers” its state until the incoming power is lost, which would

then default back to OFF.

The front panel rocker is not the primary means of control in

momentary mode, and should normally be left ON. It may be

a useful secondary means of control in the rare case of having

several PS-8R’s in parallel, if there is some reason to shut down

one unit without affecting the others.

Because it is a maintained-contact switch, the RS-1 is not an

appropriate remote switch for the PS-8R when it is in momentary

mode.The momentary-contact RS-2 would be the correct choice.

Maintained vs. Momentary Contact Switching

Maintained switches, such as most toggle switches and

push-on/push-off button switches (including the Furman RS-1),

stay open until thrown, then stay closed until thrown again.

Momentary switches, usually pushbutton types like the Furman

RS-2, are normally open and stay closed only as long as the button

is pressed. An on-off switch of either kind may be used to actuate

the PS-8’s remote operation.

Maintained switches are generally most convenient when there

is only one remote location. When more than one switch location

is required, momentary switches allow the sequence to be started

from any location.

PS-8R units come factory-set for maintained operation. They

may be easily converted to momentary operation by moving

a jumper plug on the PS-8R’s circuit board. To do this:

1. Disconnect the unit from AC power.

2. Remove the four screws that secure the top cover.

3. In the rear left corner of the circuit board, there is an area

labeled “REMOTE CONTROL.”There are two pairs of terminals

in this area, one labeled “MAINTAINED” and the other

“MOMENTARY.” There is a small black jumper linking the

MAINTAINED terminals. Slide it up and off, and replace

itsecurely over the MOMENTARY terminals.

Multiple Units

You can use more than one PS-8R to handle loads that ex-

ceed 15 amps.The power input for each PS-8R should come from

a separate 15 amp AC circuit. To control PS-8R’s remotely with

one or more remote switches, connect the REM IN +12V (and

optionally GND) terminals of all units together. Be sure that the

mode (momentary or maintained) of all units is set the same. Con-

nect a single maintained switch or one or more momentary

switches to the nearest PS-8R, as discussed above. If you are

unsure whether your building wiring can accommodate multiple

fully-loaded PS-8’s or PS-8R’s, consult a qualified electrician.

If multiple PS-8R’s are controlled by one or more momentary

remote switches, they will all change state (from on to off or vice

versa) on each rising edge of the voltage on the REM IN terminal.

Any remote switch AND any of the grey pushbuttons on any unit’s

front panel will toggle all the units.The rocker switch on each unit’s

front panel will turn off any individual unit that is currently on, with-

out affecting the other units.

The STATUS lines work the same in either mode. Each

reflects the true state of the outlets of its unit, and is affected by

both the “memorized” state and by the front panel rocker switch. A

separate LED must be used to indicate the status of each PS-8R.

To take care of the case of having several PS-8R’s in parallel

that somehow get out of sync such that every time a remote

button is pushed, some units turn on and others turn off, there is

a special feature of the remote signal line:

Holding the REM line high for at least 4 seconds (whether by

an actual remote switch or by any unit's front panel switch) will

force all units to the OFF state, which will put them back in sync.

This is the only way to re-sync units other than disconnecting AC

power to all the units. Remember — operating the front panel

rocker switch does NOT affect the stored state of the unit, even

though it does temporarily turn the outputs off.

This section covers the case of multiple units in parallel

(all sequences initiate simultaneously). See “AC Relay Accessory

PS-REL” on the following page for a discussion of wiring multiple

units in series.

4. Reattach the top cover.

Maintained Mode

A simple connection of the REM IN terminal to the +12V

terminal initiates an OFF sequence. Disconnecting it initiates an

ON sequence. If the cable run is long, it is recommended that the

REM IN wire be tied to the PS-8R’s GND terminal during ON op-

eration rather than leaving it floating. This will require the use of a

third conductor and a double-throw switch.

The STATUS terminal is an output that may be used to

illuminate an LED at the remote location to indicate that power is

available at the PowerPort’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 it is wrong). If a Furman

RS-1 is the controlling switch, contact Furman’s Tech Support de-

partment for the proper wiring diagrams.

In Maintained Mode, DO NOT USE the “START ON-OFF SE-

QUENCE” switch on the front panel. If you do, you may

activate an unintended partial turn-off sequence.

Momentary Mode

In Momentary Mode, the PS-8R has "memory" — it only needs

a momentary signal from the remote switch to change its state

from ON to OFF.

*Momentary mode switching is not available in PS-8R’s with serial numbers below H12757.

AC Relay Accessory PS-REL

PS-8, PS-8R SPECIFICATIONS

The AC Relay Accessory (model PS-REL) is a sensor which

can close a switch in response to the presence of AC power,

while only drawing a minimal amount of that power. It is

necessary whenever a PS-8R must be turned on in response to

energizing a switched outlet, where that outlet is rated less than

15 amps or is not grounded. This occurs frequently in “home

theater” installations when a small ungrounded switched outlet

on a preamp or receiver (often activated by a wireless remote

device) is to be used to power up a large amount of equipment.

The AC Relay Accessory may also be used to allow a PS-8R to

be hooked up in series to a PS-8 (or another PS-8R) to double

the number of delayed turn-on/turn-off groups, by having the

relay sense the presence of power at the DELAY 3 outlet of the

PS-8.

The PS-REL is simply a small box containing a relay. A

two-prong AC plug on a 6 foot cord activates the relay, and two

wires ending in terminals connect to the relay contacts. These

two wires should be connected to the +12V and REM IN screw

terminals of the PS-8R, with the PS-REL’s AC plug in the outlet to

be sensed.The PS-8R itself should be plugged into a separate 15

amp electrical circuit.When AC power appears at the sensed outlet,

the PS-8R will begin its turn-on sequence and will be able to sup-

ply its full rated 15 amps.

Maximum load:

PS-8: 15 amps (1800 watts at 120 VAC)

PS-8E: 10 amps (2300 watts at 230 VAC)

PS-8: 85 to 135 VAC; PS-8E: 190 to 270 VAC

Input Voltage Range:

Mains Wiring Analyzer: Detects 1 normal mode and 5 fault modes

Delay Interval:

Remote Switch

(PS-8R only):

5 seconds (adjustable with internal trimpot)

Momentary or maintained action.

Screw terminals, 3 for switch, 1 additional

for optional LED (22 ga. wiring minimum).

Spike Protection Modes: Line to neutral, neutral to ground, line to ground

Spike Clamping Voltage: PS-8: TVSS rating 400V peak, L-N, N-G, L-G

(tested to UL 1449). PS-8E: 500V peak

Response Time:

1 nanosecond

Maximum Surge Current: 6,500 amps (8 x 20 ms pulse)

Maximum Spike Energy: 80 joules per mode, 240 joules total protection

(“E” versions 130 joules L-N, 160 joules N-G,

L-G, 450 joules total)

Noise Attenuation:

PS-8 and PS-8R: Transverse and common modes:

20 dB at 200 kHz, rising to >40 dB, 1 to 100 MHz

Dimensions: 1.75" H x 19" W x 8" D.

Weight: 6 lbs (2.7 kg).

Mechanical:

Construction: Steel chassis, zinc chromate plating;

.125" brushed and black anodized aluminum front

panel; 3 oz. copper double-sided glass epoxy printed

circuit board

Power Consumption:

Switch off: 6 watts

Switch on: 8.5 watts

Blinking DELAY 1 Indicator

LISTED

7Z37

Safety Agency Approvals: UL, CUL, CE listed.

The DELAY 1 LED on a PS-8R blinks whenever the unit is

OFF due to the remote switch. In Maintained Mode, this will only

occur when the REM IN terminal is tied to +12V. In Momentary

Mode, the LED blinks if the “memorized” state is OFF.

The Furman PS-8 is manufactured in the U.S.A.

Three Year Limited Warranty