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7885-2 & 7885-3

4

Standalone Power Supply Unit 120 V dc to -24 V dc

2.

Hardware Description

For the block diagram of model 7885-2, refer to Figure 2.

Figure 2

Block Diagram

Under
Voltage
Detection

Rectifier

Output
Breaker

Input
Breaker

Transformer

Voltage
Regulator

Batteries

Filter

120 V ac in 

48 V dc out

(floating)

Current
Limit

Summary of Contents for 7885-2

Page 1: ...Standalone Power Supply Unit 120 V ac to 48 V dc 7885 2 7885 3 Description and Installation...

Page 2: ...d 2 shall use same for operating and maintenance purposes only DISCLAIMER NOTICE Although Positron Inc has made every effort to ensure the accuracy of the information contained herein this document is...

Page 3: ...nd Battery Unit 1 2 Hardware Description 4 3 Technical Specifications 6 4 Installation 7 4 1 Mechanical Installation 11 4 1 1 Wall Mount 11 4 1 2 Teleline Shelf Mount 12 4 2 Electrical Installation 13...

Page 4: ......

Page 5: ...attery Unit model 7885 3 holds two maintenance free backup batteries as does the Power Supply Unit model 7885 2 When the 7885 2 is connected to the 7885 3 the 7885 2 provides 5 7 ampere hours of batte...

Page 6: ...7885 2 3 3 7 8 MOUNTING TRAY 7885 2 RIGHT SIDE VIEW 16 1 4 7885 2 FRONT VIEW POSITRON 7885 2 MOUNTING TRAY INPUT CABLE 9 2 3 INPUT FUSE ANCHORING BRACKET OUTPUT CONNECTOR 3 7 8 7885 3 RIGHT SIDE VIEW...

Page 7: ...full wave rectification filtering and voltage regulation to perform the AC to DC conversion When model 7885 2 and 7885 3 are connected together they provide 5 7 ampere hours of charge at 48 V dc The...

Page 8: ...dc 2 Hardware Description For the block diagram of model 7885 2 refer to Figure 2 Figure 2 Block Diagram Under Voltage Detection Rectifier Output Breaker Input Breaker Transformer Voltage Regulator Ba...

Page 9: ...the filtered voltage from the input and gives out 48 V dc to the output Current Limit The Current Limit circuit is a linear current limit circuit that drops the output voltage as the current increase...

Page 10: ...ameter Specifications Battery GS Battery 12V 5 7 A h P N PE12V7F1 or equivalent Input station voltage 104 to 127 V ac Input power at full load 160 VA Nominal output voltage 48 V dc Maximum output curr...

Page 11: ...lation procedure It is preferable to perform these procedures on a clear dry day when a Ground Potential Rise GPR or transients are less likely to occur 1 Verify that you are not using any equipment w...

Page 12: ...ards variations B and C only 7501 15B C OPX Trunk Card variation B only 7501 16B Four Wire AC Data Card 7501 24 Expandable Telephone Card configured for 24 V only 751321 751321 A 751321C Two wire HDSL...

Page 13: ...r Card 7501 06A Four Wire T1 Carrier Card 751329 DC Trip DC Pilot Wire Card variation B only 7501 15B OPX Card variations B and C only 7501 16B C Four Wire AC Data Card 7501 24 Two Wire AC Data Card 7...

Page 14: ...n document 1 7885 24 02 Battery backup case assembly 1 244 040029 401 Battery backup connection assembly 1 7885 03 02 Kit for power supply 1 241 010196 401 Power supply cable 1 207 010087 401 Phillips...

Page 15: ...battery terminal Replace the power supply enclosure 4 1 Mechanical Installation The Standalone Power Supply Unit can be installed on a self supporting wall mounted tray or directly on the Teleline sh...

Page 16: ...upply enclosure with those on the left side of the mounting tray Use the two 1 2 bolts and washers to attach the two parts together 4 Model 7885 3 may be stacked on top of the model 7885 2 4 1 2 Telel...

Page 17: ...ad 0 12 or 36 volts there may be a polarity reversal of one or more batteries If there is a polarity reversal do not plug in the Power Supply Unit until the polarity reversal has been corrected For fu...

Page 18: ...the standard AC cable and plug it to a 120 V ac outlet 7 Verify the installation by making sure that you obtain 48 V dc in the shelf 8 Test the battery backup after 24 hours of continuous operation o...

Page 19: ...ssis out 3 Remove the metal plate holding the batteries to the chassis 4 Disconnect the batteries and dispose of them in a government approved waste site Caution The batteries contain toxic lead and c...

Page 20: ...dc to 24 V dc Figure 4 7885 2 3 Component Layout PCB POWER TRANSFORMER 7885 3 COMPONENT LAYOUT TOP VIEW 7885 2 COMPONENT LAYOUT TOP VIEW HEAT SINK BATTERY BATTERY 12 V DC 12 V DC BATTERY BATTERY 12 V...

Page 21: ...ents 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...

Page 22: ...ore please take this into consideration when requesting a Return Material Authorization RMA number Before returning any items to Positron for repair warranty repair or replacement call the Repair depa...

Page 23: ...ate required on site All orders must be followed by a confirming order Equipment will not be shipped until such confirmation is received For a list of our contact information refer to Table 7 Table 7...

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