CLEAR-COM ENCORE PS-704 FOUR-CHANNEL POWER SUPPLY INSTRUCTION MANUAL
PS-704 Four-Channel Power Supply Instruction Manual Part Number 810494Z Rev. 3 Legal Disclaimers Copyright © 2013 HME Clear-Com Ltd. All rights reserved. Clear-Com, the Clear-Com logo, and Clear-Com Concert are trademarks or registered trademarks of HM Electronics, Inc. The software described in this document is furnished under a license agreement and may be used only in accordance with the terms of the agreement.
CONTENTS OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1 The Clear-Com Concept. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1 Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2 Fail Safe Power . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
LIMITED WARRANTY. . . . . . . . . . . . . . . . . . . . . . . . . . 6-I Warranty Period . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-i Technical Support. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-i Warranty Repairs and Returns . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-ii Non-Warranty Repairs and Returns . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
IMPORTANT SAFETY INSTRUCTIONS Please read and follow these instructions before operating this product. 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. Read these instructions. Keep these instructions. Heed all warnings. Follow all instructions. Do not use this apparatus near water. Clean only with dry cloth. Do not block any ventilation openings. Install in accordance with the manufacturer’s instructions.
CAUTION RISK OF ELECTRIC SHOCK DO NOT OPEN This symbol alerts you to the presence of uninsulated dangerous voltage within the product's enclosure that might be of sufficient magnitude to constitute a risk of electric shock. Do not open the product's case. This symbol informs you that important operating and maintenance instructions are included in the literature accompanying this product.
OPERATION INTRODUCTION Congratulations on choosing this Clear-Com product. Clear-Com was established in 1968 and remains the market leader in providing intercoms for entertainment, educational, broadcast and industrial applications. The ruggedness and high build-quality of Clear-Com products defines the industry standard. In fact, many of our original beltpacks and main stations are still in daily use around the world.
throughout the intercom network, and is usually located in the main station or power supply. Clear-Com main stations, power supplies and certain remote stations each have an auxiliary program input with its own volume control, which allows an external audio source to be fed to the intercom system. Visual Signal Circuitry (call lights), a standard feature on all main and remote stations, allows the user to attract the attention of operators who have removed their headsets.
• AUTOMATIC POWER RESTORE: The PS-704’s internal power supply senses the difference between short-term and long-term shorts and overload conditions. After the first few times a short or overload occurs, the power supply will try to restore power after only 0.5 seconds. If the short or overload persists or occurs repeatedly, the power supply will take progressively longer (to a maximum of 20 seconds) to try to restore power. This protects the power supply from damage due to overheating.
to use the isolated power provided by the PS-704. Refer to Chapter 2‚ “Installation.” • LOW NOISE CIRCUITRY: The direct current outputs of the PS-704 contain very little hum and noise. The PS-704 does not contribute to audible noise in the remote stations and beltpacks. Note: Power supply lines connected together at remote stations will disable the individual channel short circuit protection feature. PS-704 OVERALL DESCRIPTION A brief description of the connectors and controls follows.
7. TERM. ON/OFF: Slide switch (one per channel) selects whether the PS-704 will provide termination for that channel. The default position is on. 8. INTERCOM LINE CONNECTOR: There are two 3-pin male XLR connectors per channel, wired in parallel or “looped-through.” 9. AC POWER SUPPLY INPUT: Connects to AC with an IEC cable. The PS-704’s power supply will accept any line voltage between 100 volts and 240 volts AC @ 50 Hz - 60 Hz. It will automatically adjust to the line voltage.
1 POWER SWITCH: Switches the AC power to the PS-704 on and off. When in the on position, the LED indicator to the left of the switch should illuminate. Check the short indicators for evidence of system malfunctions. 3 PROGRAM SEND ON/OFF: These toggle switches, one for each channel, connect program audio to that channel. The number of active sends will not affect the overall send level to any channel.
FRONT PANEL INDICATORS 2 OVERLOAD INDICATORS: If a short-circuit condition appears on any of the four intercom lines, the sense circuitry for that line will disconnect the DC power to that line only and the red LED for that channel will be on. If a red LED is illuminated, the fault on that channel must be located and removed. The overload LED will go out and the PS-704’s automatic short reset circuitry will automatically bring the power back up on that channel when the fault is removed.
Caution: Pin #1 and the shell of the XLR plug on the interconnect cables should NOT be connected together. CHECK INTERCOM CABLE RESISTANCE For minimal crosstalk, the ground resistance of the intercom cables should be as low as possible, preferably less than 2Ω. Disconnect an intercom line from the main station or power supply. At the point in the intercom line furthest from the unit, connect a clip lead jumper between pins #1 and #2.
INSTALLATION QUICK START 1. Unpack the unit and inspect for any damage that may have occurred during shipping. 2. Connect the proper AC mains cable. 3. Install the PS-704. 4. Connect the AC to the mains circuit. Connect the intercom lines and program input as required. 5. Set the four termination switches on the rear panel to on. 6. Switch power on. The green power light should be on and the four red short lights should be off. 7.
LINE TERMINATION (REAR PANEL) Switching of the channels’ terminations on and off are done with the rear-panel toggle switches. In most systems, all terminations on the PS-704 should be in the on position (default setting). The fundamental concept of Clear-Com party-line intercom is that all channels are terminated in one location, preferably at the power supply. Caution: All intercom lines must be terminated. Care must be taken not to “double-terminate” a line.
WIRING When considering how to wire an intercom system, several factors must be taken into account. These include the number of stations, the length of the cable runs and whether single or multiple channels are preferred. If multi-channel stations are connected with multi-pair cables, then crosstalk becomes an important issue. (Crosstalk is not a factor with single-channel systems or multi-channel systems where each channel is run on its own individual cable to single-channel remote stations.
2. Hub or Star: Each remote station is wired directly back to the power supply or to a split line wired directly to the power supply.
MULTI-CHANNEL SYSTEM In a multi-channel system where each channel is run on its own cable and connected only to single-channel remote stations as in the following diagram, there are no crosstalk issues because the channels do not share a common ground. Consult the table “Belden Shielded Cables” in the next section for cable recommendations.
CROSSTALK CONSIDERATIONS When multiple channels are fed to remote stations, the amount of crosstalk between channels is proportional to the DC resistance of the ground return path back to the channel terminations. To minimize this crosstalk between channels when running more than one channel in a multi-pair cable, keep the DC resistance of the ground return as low as possible. Ideally, this should be less than 2Ω. This can be achieved as follows: • Keep cable runs under 500 ft. (152.5 m).
cables or headset “Y” cables, as they will increase crosstalk into a multi-channel system. INTERCOM CABLE CONSIDERATIONS The Clear-Com intercom line is intended to run on one shielded cable pair per intercom channel. One conductor carries audio, the other conductor carries the DC power for remote stations. The shield serves as the ground return of the audio and power conductors. When choosing interconnect cable, keep the following considerations in mind: • Keep cable runs under 500 ft. (152.5 m).
2-8 Trade No. No. of Pairs 1815A 4 AWG & Stranding 22 (7x30) Insulation Thickness (inch) 0.05 Jacket Nom. O.D. Nom Shield Nom (Inch) Thickness Cap(pF/ft) D.C.R. (inch) (Ohms) 0.03 0.384 31 3.
MAINTENANCE INTRODUCTION This chapter provides maintenance information including a block diagram and troubleshooting tips. Caution: These servicing instructions are for use by qualified personnel only. To reduce the risk of electrical shock, do not perform any servicing other than that contained in the operating instructions unless you are qualified to do so.
TROUBLESHOOTING TIPS SYMPTOM System does not operate. No power to the PS-704. Green power LED is not illuminated and no short LEDs are illuminated. Red short LED illuminated. All red short LEDs are illuminated. Hum or buzz in system. CAUSE SOLUTION No AC power to the PS-704. Check AC connection and cable. Plug into dependable AC source. PS-704 has an internal power supply failure. Unit requires servicing. Short or overload on that channel due to a shorted or miswired cable.
SYMPTOM Excessive crosstalk. Program signal sounds distorted. CAUSE SOLUTION Channel unterminated. Set the PS-704 termination switch for that channel to the on position. A headset extension cord was used. Headset extension cords are not recommended. High DC resistance in ground return. Use heavier cable; add additional conductor(s) to ground return. Multi-channel cable pairs are not individually shielded. Replace cable with individually shielded pairs.
3-4 PS-704 FOUR-CHANNEL POWER SUPPLY
TECHNICAL SPECIFICATIONS PS-704 FOUR-CHANNEL POWER SUPPLY dBu is an absolute measurement. 0 dBu is referenced to 0.775 volts RMS Program Line Input Maximum Level before Clipping Input Impedance Frequency Response Program Input - Party Line Max Distortion Program Input - Party Line Noise Program Mic Input - Party Line Max Gain Program Input - Party Line Min Gain Program Input - Party Line >= 20dBu >= 5KΩ 200 - 20KHz ± 3dB <= 0.
Rear Panel Connectors Intercom: Program: AC Power: Rear Panel Controls Front Panel Controls & Indicators Environmental Dimensions (8) XLR-3M (2 per channel) (1) XLR-3F IEC 320 connector (4) Termination On-Off switches (1) Volume control (4) Program switch (4) Send level controls (4) Overload LEDs (1) Power indicator LED (1) Power switch 32 - 122o F (0 - 50o C) 19 in. W x 1.75 in. H x 7.5 in. D (483 mm x 44 mm x 190 mm) Weight 6.16 lbs. (2.
GLOSSARY Some of the terms used when discussing critical communications for television or theatre may be new to you as they are unique to intercom applications. Although many of the terms are common to other audio applications, to be certain you understand their meanings we offer the following definitions: All Call: Ability to push one button from the main station and talk to all channels at once on a multiple channel system.
voices and instruments on stage. IFB (program interrupt) disconnects the audio source while the talk button on the main station is pushed. ISO: A private conversation path. An ISO channel allows one to simply push a button and transfer themselves and the person they wish to speak with to an isolated channel. Linking: Linking ties separate channels into one single party line.
LIMITED WARRANTY Clear-Com offers 24 x 7 customer support if you have an Extended Warranty or Service Contract. Return Material Authorization (RMA) numbers are required for all returns. Both warranty and non-warranty repairs are available. Clear-Com warrants that at the time of purchase, the equipment supplied complies with any specification in the order confirmation when used under normal conditions, and is free from defects in workmanship and materials during the warranty period.
period will be offered at no charge between 09:00 and 17:00 according to the customer’s local time zone. In addition, for customers who purchase an Extended Warranty or Service Contract, 24-hour customer support is offered immediately upon purchase of such agreement. For more information, contact your authorized dealer, distributor, or sales representative. Instructions for reaching Clear-Com’s User Support Centers are given below. Americas and Asia-Pacific Headquarters California, United States Tel: +1.
Clear-Com has the right to inspect the equipment and/or installation or relevant packaging. NON-WARRANTY REPAIRS AND RETURNS For items not under warranty, you must obtain an RMA by contacting the User Support Center. Clear-Com representatives will give you instructions and addresses for returning your equipment. You must pay all charges to have the equipment shipped to the support center and returned to you, in addition to the costs of the repair.
LIMITATION OF INCIDENTAL OR CONSEQUENTIAL DAMAGES OR THE LIMITATION ON HOW LONG AN IMPLIED WARRANTY LASTS, SO THE ABOVE LIMITATIONS MAY NOT APPLY TO YOU. IN ANY EVENT, TO THE MAXIMUM EXTENT PERMITTED UNDER APPLICABLE LAW, CLEAR-COM'S LIABILITY TO CUSTOMER HEREUNDER SHALL NOT UNDER ANY CIRCUMSTANCES EXCEED THE COST OF REPAIRING OR REPLACING ANY PART(S) FOUND TO BE DEFECTIVE WITHIN THE WARRANTY PERIOD AS AFORESAID.
