Positron Teleline 751221 Description And Installation

Standalone telephone unit isolator

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Standalone Telephone Unit, 751221

Description and Installation

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Page 1 Standalone Telephone Unit, 751221 Description and Installation...
Page 2 The information contained in this document is the property of Positron Inc. Except as specifically authorized in writing by Positron Inc., the holder of this document: 1) shall keep all information contained herein confidential and shall protect same in whole or in part from the disclosure and dissemination to all third parties, and 2) shall use same for operating and maintenance purposes only.
Page 3: Table Of Contents
Contents The Standalone Telephone Unit ........... . . 1 Applications .
Page 5: The Standalone Telephone Unit
751221 (22 pages) Standalone Telephone Unit The Standalone Telephone Unit The Standalone Telephone Unit, model 751221, provides high voltage isolation between a telephone line and the drop side of one loop start telephone circuit (telephone, dial-up modem, or loop start private branch exchange (PBX)). The unit consists of an isolator card and a power supply mounted inside a small compact enclosure.
Page 6 - THIS COVER MUST ALWAYS BE CLOSED AS IT PROVIDES 13-1/2" THE NECESSARY SPECIAL SAFETY INSULATION TO PROTECT PERSONNEL FROM DANGEROUS VOLTAGES PRESENT DURING GROUND FAULT CONDITIONS - WHEN WORKING IN THE CABINET USE RUBBER GLOVES AND INSULATED CARPET POSITRON SIDE VIEW 5- 9/16" GROUND...
Page 7 751221 Standalone Telephone Unit Figure 2 Model 751221 Cover Open (Only Major Components Shown) POWER SUPPLY GND LUG Power In (green LED) Power Out (yellow LED) (2A,250V) Low Battery (red LED) RETAINING CLAMP (6A, 32V) BATTERY -24V MAIN POWER BOARD SUPPLY OUTPUT CONNECTOR...
Page 8: Applications
751221 Standalone Telephone Unit Applications The applications of the Standalone Telephone Unit include the following: • Loop start plain old telephone service (POTS) • Dial-up “smart” modems (up to 19200 baud) • Fax lines (up to19200 baud) • Loop start PBX •...
Page 9: Hardware Description
751221 Standalone Telephone Unit Hardware Description The Standalone Telephone Unit contains the Fiberline Telephone card. This card is comprised of two sides. The Station side is located on the upper portion of the card and the CO side is located on the lower portion of the card. The Station side is separated from the CO side by the opto-isolators, which create a 5¼...
Page 10 751221 Standalone Telephone Unit Hybrid Voice Circuits The Hybrid Voice Circuits located on both the Station and CO sides of the card form a two-wire to four-wire to two-wire configuration that permits the separation of Transmit (TX) and Receive (RX) signals. These circuits also perform an impedance matching function such that the Station side impedance is reflected to the CO side.
Page 11 751221 Standalone Telephone Unit Main Isolator Bias Circuit The Main Isolator Bias Circuit generates the off-hook and ring trip signals, and feeds a -24 V dc (on-hook potential) bias to the Station side telephones. Power Supply PCB The Power Supply PCB accepts either 120 V ac or -24 to 130V dc, and provides -24 V dc to the Station side circuitry.
Page 12: Technical Specifications
751221 Standalone Telephone Unit Technical Specifications For a listing of the unit’s electrical specifications, refer to Table 1. For a listing of the unit’s physical specifications, refer to Table 2. Table 1 Electrical Specifications (measured at 77°F or 25°C, 50% R.H) Parameter Specifications ISOLATION DATA:...
Page 13 751221 Standalone Telephone Unit Parameter Specifications NOISE (Off-hook, 40 mA dc) Impulse noise (both sides) Less than 1 count in 30 minutes above 48 dBrnCz Phase jitter < 0.5°, 300 to 3400 Hz Common mode rejection ratio (from CO to >80 dB, 300 to 3400 Hz Station side, terminated in 600 or 900Ω) Noise (2 Hz to 100 Hz)
Page 14 751221 Standalone Telephone Unit Parameter Specifications BATTERY TIME AVAILABLE (with new, fully charged battery) On-hook (idle) 17 hours minimum or: ringing (1 ringer) 5.5 hours minimum or: off-hook 5.5 hours minimum Composite specification 10 hrs idle + 2 hrs off-hook + 20 minute ringings BATTERY SERVICE LIFE 4 years (minimum)
Page 15: Installation
751221 Standalone Telephone Unit Installation The Standalone Telephone Unit is used when the number of lines to be isolated does not justify the installation of a shelf. It will isolate one telephone circuit and is powered from an AC or DC source. To view the Standalone Two-wire Telephone Units’...
Page 16 751221 Standalone Telephone Unit Note This unit can be powered by 120 V ac or a DC voltage source of 24 V dc to 130 V dc (maximum of 150 V dc). The input power is not polarity sensitive. The power connections are made at TB1 on the power supply board (see Power &...
Page 17 When moving the card, carry it in an ESD safe container or the antistatic bag, provided with the card. Failure to follow ESD precautions may void the warranty. For further information concerning ESD precautions, contact Positron’s Customer Support department. • Power should only be applied after all wiring is completed. The station...
Page 18 751221 Standalone Telephone Unit Table 3 Model 751221 Kit Contents Items Included Part Numbers Standalone Telephone Unit 244-751221-401 Description and Installation document 7501-24-52 One-card Shelf accessory kit 7501-22-02 6’ power cable (3-conductor) 207-990000-020 10’ insulated cable (12-conductor) 207-990000-138 Connector cord grip (1/2” hub) 230-990400-036 Connector cord grip (1/2”...
Page 19 751221 Standalone Telephone Unit The power supply board is not fastened to the main isolation card prior to shipment and, therefore, requires installation first. Unfasten the cover of the unit and proceed as follows: ? Remove the screws from the tops of the spacers mounted on the Station side circuit board.
Page 20 751221 Standalone Telephone Unit ? Strip back the outer jacket of each cable one inch. Strip the inner insulating jacket of each conductor 1/8”. Connect these stripped conductors to the designated terminal locations. For a listing of the terminal block connections, refer to Table 4.
Page 21 751221 Standalone Telephone Unit 13. Measure the voltage across the terminals of J4 on the main PCB of the unit. The voltmeter should register 23 to 25V dc with the subscriber telephone on-hook. 14. Ensure that there are no excess wires dangling into the isolation gap between the Station and CO side circuits.
Page 22: Battery Replacement Procedure
751221 Standalone Telephone Unit Battery Replacement Procedure Replacement of the battery will be necessary after its rated service life has expired. Its rated service life is at least four years. It is to be replaced by a Sonnenschein 12V/1.2 Ah A212/1.2S unit or equivalent. Remove the retaining clamp holding the battery in place.
Page 23: Service And Support
Arrangements and pricing information regarding field assistance may be obtained by contacting the Technical Customer Support department. Please contact Positron for scheduling at least four weeks prior to the actual requested visit date. Customer Training Positron offers full customer training courses, as requested.
Page 24 Positron Inc. offers repair services by which customers can count on timely and quality repairs, regardless of customer location. All warranty repairs are performed at no cost. Positron reserves the right to repair or replace any equipment which has been found to be defective.
Page 25 Standalone Telephone Unit Ordering Information Positron’s Teleline equipment can be ordered by telephone, facsimile, or by mail. All orders should be directed to the Positron Inside Sales department. Ordering by telephone, or facsimile will eliminate any delays arising from postal services.