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: info@furmansound.com Power Sequencer MODELS PS-8, PS-8R, PS-8E and PS-8RE Instruction Sheet PS-8 .eatures q q q q q q q q 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 Power Sequencing .eatures 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 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. 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. 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 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 960032-1051 q q q q q q 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 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 Rear Panel Outlets Model PS-8R is shown. Model PS-8 is similar except the barrier terminal strip at right is not present. 120 VAC 60 HZ 15A UNSWITCHED 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. DELAY 1 120 VAC 60 HZ AVIS: RISQUE DE CHOC ELECTRIQUE--NE PAS OUVRIR DELAY 2 DELAY 3 CLASS 1 WIRING +12V STATUS 15 A M P ® ® REM IN GND MAX LOAD 15A LISTED 7Z37 PROFESSIONAL AUDIO EQUIPMENT ON POWER UP: This pair of outlets plus the one on the front panel are on regardless of the switch position. Same as above. 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. ON POWER DOWN: This pair of outlets goes off approx. 10 seconds after the switch is turned off. 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. 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. Mains Wiring .ault Analyzer The PS-8 also assists in analyzing any faults that may occur 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 presents a potentially serious safety hazard, the assistance of a qualified electrician should be obtained in correcting the problem. Power Conditioning .eatures The PS-8 offers all basic power conditioning features 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 your rack to different locations, derive power 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 voltage regulator, run the raw 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 for 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. 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 parallel with, and functionally equivalent to, one or more remote momentary 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. 4. Reattach the top cover. Multiple Units You can use more than one PS-8R to handle loads that exceed 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. Connect 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 accom ...