UNITED STATES DEPARTMENT OF AGRICULTURE

Rural Electrification Administration

SUBJECT: Power Requirements for Digital Central Office Equipment

To: All Telephone Borrowers

REA Telephone Staff

EFFECTIVE DATE: Date of Approval

EXPIRATION DATE: Three years from effective date

OFFICE OF PRIMARY INTEREST: Central Office Equipment Branch,

Telecommunications Standards Division

PREVIOUS INSTRUCTIONS: This bulletin replaces REA

Telecommunications Engineering & Construction Manual (TE&CM) Section 302, Power Requirements for Community Central Office Equipment, Issue No. 6, dated April 1989.

FILING INSTRUCTIONS: Discard REA Telecommunications Engineering & Constructions Manual (TE&CM) 302, Power Requirements for Digital Central Office Equipment, Issue 6, dated April 1989, and replace it with this bulletin. File with 7 CFR 1751 and on REANET.

PURPOSE: This bulletin provides REA borrowers, and other interested parties with information concerning power requirements for digital central office equipment.

James B. Huff Sr. 10/15/93

____________________________ ___________________________

Administrator Date

1. GENERAL.....................................................4

2. BASIS FOR CALCULATIONS......................................4

3. CALCULATIONS................................................6

FIGURE 1 - NORTHERN TELECOM, DMS-100......................8

FIGURE 1.1 - NORTHERN TELECOM DMS-100 (EXAMPLE).............9

FIGURE 1.2 - NORTHERN TELECOM DMS-100......................10

FIGURE 1.3 - NORTHERN TELECOM DMS-100 (EXAMPLE)............11

FIGURE 1.4 - NORTHERN TELECOM DMS-10 400 SERIES............12

FIGURE 1.5 - NORTHERN TELECOM DMS-10 400 SERIES (EXAMPLE)..13

FIGURE 1.6 - NORTHERN TELECOM DMS-10 400 SERIES............14

FIGURE 2 - SIEMENS STROMBERG-CARLSON DCO DCO-E/DCO-SE....16

FIGURE 2.1 - SIEMENS STROMBERG-CARLSON DCO DCO-E/DCO-SE....19

FIGURE 3 - REDCOM MDX....................................22

FIGURE 4 - AT&T 5ESS SWITCH..............................23

FIGURE 4.1 - AT&T 5ESS SWITCH (EXAMPLE)....................25

FIGURE 5 - MITEL GX5000..................................27

FIGURE 5.1 - MITEL GX5000 (EXAMPLE)........................28

FIGURE 6 - TRANSMISSION ELECTRONICS CURRENT DRAIN........29

FIGURE 7 - ESTIMATING TELEPHONE BATTERY SIZES............30

FIGURE 8 - CHARGER CAPACITY..............................31

INDEX:

Power Requirements For Digital Central Office Equipment

AC Alternating Current

AH Ampere Hour

AM Administrative Module

AMAF Automated Message Accounting Frame

BHA Busy Hour Attempts

BMC Billing Media Converter

BTU British Thermal Unit

CC Common Control

CCS Hundred Call Seconds

CM Communication Module

CMF Control and Maintenance Frame

COE Central Office Equipment

CPU Central Processing Unit

CUA Circuit Unit Assembly

DAT Digital Analog Trunk

DC Direct Current

dc-ac direct current - alternating current

dc-dc direct current - direct current

DCI Digital Carrier Interface

DCM Digital Carrier Module

DCO-E Digital Central Office Exchange

DCS-SE Digital Central Office Small Exchange

DCTU Digital Carrier Trunk Unit

DLTU Digital Line & Trunk Unit

DTC Digital Trunk Controller

DTMF Dual - Tone Mutlifunction

GDSU Global Digital Service Unit

GPIO General Purpose Input Output

LCE Line Concentrating Equipment

LCE Line Concentrator Equipment

LGC Line Group Controller

LLS Local Line Switch

LTF Line Trunk Frame

LU Line Unit

MDX Modular Digital Exchange

MMSU Modular Metallic Service Unit

MSU Modular Shelf Unit

MTM Maintenance Trunk Module

OPM Outside Plant Module

OPSM Outside Plant Subscriber Module

P.E. Peripheral Equipment

PCCM Power Cooling Control Module

PDC Power Distribution Center

PWBA Printed Wire Board Assembly

RLCM Remote Line Concentrator Module

RLG Remote Line Group

RSLE Remote Line Subscriber Equipment

RSLM Remote Subscriber Line Module

SCM Subscriber Carrier Module

SLC Subscriber Loop Carrier

T&M Trunk and Maintenance

TM Trunk Module

TMF Toll Multifunction

TU Trunk Unit

v volts

1.1 This bulletin is intended to provide REA borrowers, consulting engineers, contractors and other interested parties with technical information for use in the design and construction of REA borrowers' telephone systems. It discusses, in particular, the methods used in calculating the power requirements for central offices. It provides means to calculate the required capacities of the storage batteries and charging equipment for particular applications.

1.2 This bulletin replaces REA TE&CM 302, Power Requirements for Digital Central Office Equipment, Issue No. 6, dated April 1989. This bulletin provides power calculation methods for various digital, stored program controlled central office equipment.

1.3 General specifications governing storage battery and charging equipment for proposed Central Office Equipment (COE) are covered in Items 12.1 and 12.2, Part III, of Bulletin 1753E-001 (Form 522), "REA General Specification for Digital, Stored Program Controlled Central Office Equipment." Based on these general specifications, determination of the required capacities of battery and charger is made by the manufacturer.

2.1 Charging equipment furnished with a central office should have sufficient capacity to supply the dc power necessary for the satisfactory operation of the office during the busy hour. This includes the dc requirements for carrier, loop extenders, voice frequency repeaters, and dc-dc converters or dc-ac inverters to operate input/output devices.

2.1.1 Determination of the requirements for emergency generating and charging equipment is covered in Bulletin 1751E-320, "Emergency Generating and Charging Equipment." A suggested method of charger size computation is provided in Figure 8.

2.2 Charging equipment for digital central offices should be provided on one of the following bases:

(a) Two chargers either of which is capable of carrying the

full office load; or

(b) Three chargers each of which is capable of carrying

half the office load.

Arrangement (a) may be used in any central office power system. Arrangement (b) may offer potential cost savings when applied to power requirements in relatively large digital, stored program controlled offices.

2.3.1 The storage battery furnished with a central office should have sufficient capacity to supply the dc power necessary to sustain satisfactory operation of the exchange for the period specified.

Specific REA minimum requirements are in 7 CFR 1755.522, which is also contained in Part III of REA Bulletin 1753E-001 (Form 522). Appropriate allowances should be included for any equipment which is normally ac operated but arranged for dc operation in case of an ac failure. See paragraph 1.3 of this bulletin for location of specific requirements in central office equipment specifications.

2.3.2 The minimum usable voltage to be delivered to the central office equipment during battery discharge should be determined using COE manufacturer's design criteria. When power flows from the battery through the power board to the equipment, a voltage drop (IR loss) is experienced as a result of the resistance of the current carrying conductors. In many cases equipment design is based on 44 volts being available at the power entry to the bay. Performance of the digital COE at voltages less than 44 volts becomes unpredictable. For effective design, voltage drop from the source to the equipment bay is considered by allocation as follows:

Battery to Power Board 0.5

Power Board to Equipment Bay 0.5

Minimum Equipment Voltage 44.0

Total 45V dc - 45.0 Vdc

In the case of a 24-cell battery (45/24) = 1.88 volts per cell becomes the minimum operating voltage.

2.3.3 The computation of battery size to meet the site power requirement is described in Figure 7 - Estimating Telephone Battery Sizes. This method permits computation with differing numbers of hours of reserve and numbers of cells in the battery string. The computation is applicable to lead-acid batteries, lead antimony, or lead-calcium batteries (see manufacturer's data for capacity, dimensions, etc.).

2.3.4 REA recommends that the battery provided should have the capacity to maintain the central office load for a period of 8 hours. Systems that are equipped with emergency generators are allowed to reduce the 8 hours to a 3-hour reserve time.

2.3.5 Determination of battery capacity to be supplied should be based on power outages experienced at the site and on the evaluation of the future performance of the ac power system. Another consideration is the size of the dc load to be supplied. Small electromechanical switching systems have a limited amount of fixed power consuming devices, while a large part of system devices only require power when in use. As a result battery capacity determinations were made assuming busy hour switching activity. The telecommunications industry considers 8 busy hour battery capacity appropriate for most small installations. The expectation of 8 consecutive busy hours of usage following a power interruption was negligible, resulting in battery power being usable for longer than the 8-hour period. Power consumption in digital switching equipment is almost constant, whether or not calls are being processed. In addition, the total power consumed by digital switches is greater than the electromechanical systems. The concept of "busy hour drain" has lost its impact in digital offices where the operating drain represents the constant load. The solution most often used is to provide an emergency generator to supply power on a long-term basis and to install a battery with 3 hours capacity.

3.1 The following sample calculations describe the suggested procedure to determine the power requirements for digital, stored program controlled central office equipment. Sample calculations are included for the following switching equipment types:

System

Manufacturer Designation

Figure 1 - Northern Telecom DMS-100, DMS-10

Figure 2 - Siemens Stromberg-Carlson DCO

Figure 3 - Redcom MDX

Figure 4 - AT&T 5 ESS

Figure 5 - Mitel GX5000

3.2 Figure 6 lists various power requirements for loop extenders, voice frequency repeaters, carrier equipment and other equipment.

3.3 Figure 7 illustrates the method used in determining the capacity of a storage battery required for a particular application. This figure also illustrates, in Example 2, a method for calculating the ampere-hour reserve of existing batteries when the current requirement of the central office equipment is changed as a result of equipment additions or higher than anticipated calling rates, etc.

3.4 Figure 8 illustrates the suggested method used in determining charger capacity required for a particular application. If 110 percent of the rated output of the charger is equal to or greater than the calculated charger dc current requirement, the charger is considered as satisfactorily meeting the specification requirements. Three suggested solutions in terms of the number of chargers and their capacity are included.

3.5 In some cases specialized equipment requires power at a voltage different from the -48V dc central office battery. Dc-dc converters can be supplied at +24V dc, +48V dc, +130V dc and other values. These other voltages are used to supply radio and carrier equipment operated at -24 volts, coin collect circuits at +130 volts and other equipment. The power required by the dc-dc converters has to be included in the total load to be carried by the central office dc power system.

3.6 It should be kept in mind that the calculation methods shown in this section are to provide estimates only. Engineering judgment has to be used for each individual application. It is, therefore, recommended that the manufacturer of the system be consulted for specific applications.

Figure 1 NORTHERN TELECOM DMS-100

1. Basic (CPU) 78.5

CC Frame E/W 4 Memory Shelves

I/O Frame E/W 2 Disk + 1 Mag Tape

2. PDC Bays x 6.5 Amps _____

3. LAMA or CAMA (10 Amps) _____

4. Combined Network Frame x 24 Amps _____

5. Double Shelf Network x 14 Amps _____

6. DTC x 8.5 Amps _____

7. MTM x 3.3 Amps _____

8. TM x 2.2 Amps _____

9. LGC x 8.5 Amps _____

10. Line Circuits LCE _______ x 8.2 + 4W (Note 1) _____

Subtotal _____

Customer Drain _______ _____

DMS Current Total _______ _____

Note 1: W = 2 way CCS per line in unit drain formula

Figure 1.1 NORTHERN TELECOM DMS-100

1000 Lines, 50 Digital Trunks, 50 Analog Trunks, 3.2 CCS/Line

I/O Frame E/W 2 disk + 1 Mag Tape Drive

3. LAMA or CAMA, 10 Amps _____

4. Combined Network Frame 1 x 24 Amps 24.0

5. Double Shelf Network x 14 Amps _____

6. DTC 1 x 8.5 Amps 8.5

7. MTM 4 x 3.3 Amps 13.2

8. TM 1 x 2.2 Amps 2.2

9. LGC 1 x 8.5 Amps 8.5

10. Line Circuits LCE 1 x 8.2 + 4W (Note 1) 21.0

(Sample = 1 x 8.2 + 4 x 3.2 = 21)

Subtotal 162.4

DMS Current Total 182.4

NOTE 1: W = 2 way CCS per line in unit drain formula

Figure 1.2 NORTHERN TELECOM DMS-100

Heat

Dissipation

Per Frame Total Heat

Type of Frame Quantity (Watts/Hr) Dissipation

Central Control Complex 1720 ___________

Input/Output Frame 850 ___________

Miscellaneous Equipment 220 ___________

Network Combined 1000 ___________

Digital Trunk Equipment 1120 ___________

Trunk Module Equipment

Frame 480 ___________

Line Concentrating

Equipment 1050 ___________

Line Group Equipment 980 ___________

Power Distribution Center 200 ___________

Figure 1.3 NORTHERN TELECOM DMS-100

1400 Lines, 50 Digital Trunks, 50 Analog Trunks, 3.2 CCS/L

Heat

Dissipation

Per Frame Total Heat

Type of Frame Quantity (Watts/Hr) Dissipation

Central Control Complex 1 1720 1720

Input/Output Frame 1 850 850

Miscellaneous Equipment 1 220 220

Network Combined 1 1000 1000

Digital Trunk Equipment 1 1120 1120

Trunk Module Equipment

Frame 2 480 960

Line Concentrating

Equipment 1 1050 1050

Line Group Equipment 1 980 980

Power Distribution Center 1 200 200

Figure 1.4 NORTHERN TELECOM STANDARD DMS-10 400 SERIES

Basic System 25.0 Amps

DCM Shelves x 4.0 = Amps

DCI Shelf x 3.0 = Amps

SCM-10S x 10.0 = Amps

P.E. Shelf x 0.75 = Amps

LCE Lines x 0.015 = Amps

BMC x 5.0 = Amps

D.C./A.C. Inverter (0.5 KW)________ x 15 = Amps

Total = Amps

D.C. Drain

Northern Telecom DMS-10 400 Generic (3 Bay)

Basic System 30.0 Amps

P.E. Shelf x 0.75 = Amps

DCM Shelf x 4.0 = Amps

LCE Lines x 0.015 = Amps

Total = Amps

D.C. Drain x 52 Watts

Figure 1.5 NORTHERN TELECOM STANDARD DMS-10 400 SERIES

Example #1

5000 Lines, 576 Trunks, 1 RLCM, 1 SLC-96, 1 RSLE, 1 RSLM

@ 3.2 CCS/line

Basic System 25.0 Amps

DCM Shelves 4 x 4.0 = 16.0 Amps

DCI Shelf 1 x 3.0 = 3.0 Amps

SCM-10S 1 x 10.0 = 10.0 Amps

P.E. Shelf 2 x 0.75 = 1.5 Amps

LCE Lines 5000 x 0.015 = 75.0 Amps

BMC 2 x 5.0 = 10.0 Amps

D.C./A.C. Inverter (0.5 KW) 1 x 15.0 = 15.0 Amps

Total = 155.5 Amps

DC Drain 155.5 x 52 = 8086 Watts

Northern Telecom DMS-10 400 Generic (3 Bay)

1280 Lines, 144 Trunks, @ 3.2 CCS

Basic System 30.0 Amps

P.E. Shelf 2 x 0.75 = 1.5 Amps

DCM Shelf 1 x 4.0 = 4.0 Amps

LCE Lines 1280 x 0.015 = 19.2 Amps

Total = 54.7 Amps

Heat Dissipation

D.C. Drain 54.7 x 52 = 2844 Watts

Figure 1.6 NORTHERN TELECOM STANDARD DMS-10 400 SERIES

(Page 1 of 2)

1 - Standard 400 Series AMPS

Basic System Current Drain 25.0

Network Module (Max. = 2 Modules) 12.0

DCM Shelf 4.0

DCI Shelf 3.0

SCM-10 (DMS-1) Shelf 4.0

SCM-10S (SLC-96) Module 10.0

Mag Tape Bay 7.8

BMC (each) 5.0

DC/AC Inverter 0.5 KW 15.0

DC/AC Inverter 1.0 KW 26.0

P.E. Lines 0.020

P.E. Shelf (with service circuits) 0.75

LCM Lines (per line) 0.015

2 - DMS-10 400 Series (3 bay) AMPS

Basic System Current Drain 30.0

(includes combination CPU/Network

shelf and GPIO shelf)

3 - DMS-10 400 series (2 bay) AMPS

CONTROL AND TRUNK BAY

CPU/Network Shelf (5.8 amps ea. two required) 11.6

GPIO Shelf 4.8

T & M Shelf 2.9

PCCM Shelf 1.5

DAT Shelf 2.9

LINE AND TRUNK BAY

Two Shelf LCM (E/W 640 Lines) 9.6

Bay Supervisory Panel 0.2

DAT Shelf each (max. = 2 shelves) 2.9

4 - DMS-10 400 Series (1 bay) AMPS

CPU/Network Shelf (5.8 amps ea. two required) 11.6

T & M Shelf 2.9

PCCM Shelf 1.5

DAT Shelf 2.9

FSP (Frame Supervisory Panel) and

LCM Shelf (E/W 256 lines) 4.8

Figure 1.6 NORTHERN TELECOM STANDARD DMS-10 400 SERIES

(Page 2 of 2)

5 - OPM AMPS

One Cabinet 15.0

Line Current 0.015/L

6 - OPSM AMPS

One Cabinet 9.0

Line Current 0.015/L

7 - RSLM AMPS

RSLM Bay 6.0

Line Current 0.015/L

8 - RSLE AMPS

RSLE Bay (up to 512 lines) 10.5

RSLE Bay (from 512 to 1024 lines) 21.0

Line Current 0.015/L

9 - RLCM AMPS

RLCM Bay 10.0

LCE Bay 0.015/L

Figure 2 SIEMENS STROMBERG - CARLSON DCO-E/DCO-SE

(Page 1 of 3)

1. CONTROL & MAINTENACE FRAME (CMF) WATTS

DCO-E CMF (ONE PER DCO-E) 1 X 2400 =_____

DCO-SE CMF (ONE PER DCO-SE) 1 X 2000 =_____

2. LOCAL LINE SWITCH FRAME (LLS) (DCO-E & DCO-SE)

Quantity of Lines ________ x ____CCS/L X 0.069 (LOAD) =_____

Quantity of Lines _____ X 0.158 (IDLE) =_____

Quantity Of Line CUAs _____ X 30.0 =_____

Quantity of RLG Host CUAs _____ X 31.0 =_____

Quantity of SLC Host CUAs _____ X 158.0 =_____

Quantity of LLS Frames _____ X 306.0 =_____

TOTAL LLS FRAME POWER REQUIREMENTS =_____

3. LINE/TRUNK FRAME POWER (LTF) (DCO-E ONLY) WATTS

Quantity of DTMF Receiver PWBAs _____ X 19.3 =_____

Quantity of DTMF Sender PWBAs _____ X 5.0 =_____

Quantity of TMF Receiver PWBAs _____ X 8.5 =_____

Quantity of TMF Sender PWBAs _____ X 3.9 =_____

Quantity of Busy Verification PWBAs _____ X 2.3 =_____

Quantity of Analog Trunk PWBAs _____ X 8.2 =_____

Quantity of LTF CUAs _____ X 19.3 =_____

TOTAL LTF POWER REQUIREMENTS =_____

4. DIGITAL TRUNK FRAME POWER (DTF) (DCO-E ONLY) WATTS

Quantity of T1 Interface PWBAs _____ X 11.2 =_____

Quantity of Message Assemblers _____ X 57.3 =_____

Quantity of DTF CUAs 67.4 =_____

5. POWER RINGING & TEST FRAME POWER (PRTF) (DCO-E ONLY) WATTS

Power Ringing & Test Frame 1 X 92.0 = 92.0

TOTAL PRTF POWER REQUIREMENTS = 92.0

Figure 2 SIEMENS STROMBERG-CARLSON DCO-E/DCO-SE

(Page 2 of 3)

6. DATA COLLECTION FRAME POWER (AMAF)/(DCF) (DCO-E & DCO-SE) WATTS

AMA Frame (E/W Tape Drives) _____ x 495.0 =_____

CODC Data Collection Frame _____ X 523.0 =_____

TOTAL AMAF/DCF POWER REQUIREMENTS =_____

7. COMMON EQUIPMENT FRAME POWER (CEF) (DCO-E) & DCO-SE) WATTS

Variable (Dependent on OEM Equipment Installed)

TOTAL CEF POWER REQUIREMENTS =_____

8. UNIVERSAL POWER FRAME (DCO-SE ONLY) WATTS

Universal Power Frame (UPF) 1 X 92.0 = 92.0

Expanded Ringing CUA _____ X 70.0 =_____

*Universal Service CUA _____ X 155.0 =_____

*Universal Trunk/Service CUA _____ X 155.0 =_____

*Universal Trunk CUA _____ X 132.0 =_____

*Customber Trunk Group CUA _____ X 107.0 =_____

Quantity of DTMF Receiver PWBAs _____ X 19.3 =_____

Quantity of DTMF Sender PWBAs _____ X 5.0 =_____

Quantity of TMF Receiver PWBAs _____ X 8.5 =_____

Quantity of TMF Sender PWBAs _____ X 3.9 =_____

Quantity of Busy/Verification PWBAs _____ X 2.3 =_____

Quantity of Analog Trunk PWBAs _____ X 8.2 =_____

TOTAL UPF POWER REQUIREMENTS =_____

9. REMOTE LINE SWITCH POWER (RLS) WATTS

RLS Frame (1080 Lines Maximum) 1 X 906.0 =906.0

Quantity of Lines _____ X _____ CCS/L X 0.069 (LOAD) =_____

Quantity of Lines _____ X 0.158 (IDLE) =_____

Quantity of Line CUAs _____ X 30.0 =_____

Quantity of RLG CUAs _____ X 31.0 =_____

Quantity of SLC CUAs _____ X 158.0 =_____

*ONLY 3 CUAs TOTAL CAN BE EQUIPPED

Figure 2 STROMBERG-CARLSON DCO-E/DCO-SE

(Page 3 of 3)

10. REMOTE LINE SWITCH - 450 POWER (DC) WATTS

Basic DC Power (Maximum) = 1200

Maximum Allowed Customer Power = 250

RLS-450 DC POWER TOTAL WATTS (Maximum) = 1450

RLS-450 RATED AC POWER INPUT (Typical) = 6000

(Based on cold weather heating plus maximum short term load.)

11. DCO-E SYSTEM POWER WATTS

Total Control & Maintenance Frame Power = 2400

Total Local Line Switch Power =_____

Total Line/Trunk Frame Power =_____

Total Digital Trunk Frame Power =_____

Total Power Ringing & Test Frame Power = 92.0

Total AMA/Data Collection Frame Power =_____

Total Common Equipment Frame Power =_____

TOTAL DCO-E SYSTEM DC POWER REQUIREMENTS =_____ AMPS

52.1 Volts) =_____

12. DCO-SE SYSTEM POWER WATTS

Total Control & Maintenance Frame Power = 2000

Total Local Line Switch Frame Power =_____

Total AMA/Data Collection Frame Power =_____

Total Universal Power Frame Power =_____

Total Common Equipment Frame Power =_____

TOTAL DCO-SE SYSTEM DC POWER REQUIREMENTS =_____

TOTAL DCO-SE DC BUSY HOUR LOAD =_____ AMPS

(Total DC Power divided by 52.1 Volts)

Figure 2.1 SIEMENS STROMBERG-CARLSON DCO-E/DCO-SE

(Page 1 of 3)

1000 LINES AT 3.2 CCS

1. CONTROL & MAINTENANCE FRAME POWER (CMF) WATTS

DCO-E 1 X 2400 = 2400

DCO-SE 1 X 2000 = 2000

2. LOCAL LINE SWITCH FRAME (LLS) (DCO-E & DCO-SE) WATTS

Quantity of Lines 1000 X 3.2 CCS/L X 0.069 (LOAD) 220.8

Quantity of Lines 1000 X 0.158 (IDLE) = 158.0

Quantity of Line CUAs 12 X 30.0 = 360.0

Quantity of RLG Host CUAs 0 X 31.0 = 0

Quantity of SLC Host CUAs 0 X 158.0 = 0

Quantity of LLS Host CUAs 1 X 306.0 = 306.0

TOTAL LLS FRAME(S) POWER (WATTS) =1044.8

3. LINE/TRUNK FRAME POWER (LTF) (DCO-E ONLY)

Quantity of DTMF Receiver PWBAs 2 X 19.3 = 38.6

Quantity of DTMF Sender PWBAs 2 X 5.0 = 10.0

Quantity of TMF Receiver PWBAs 2 X 8.5 = 17.0

Quantity of TMF Sender PWBAs 2 X 3.9 = 7.8

Quantity of Busy Verification PWBAs 2 X 2.3 = 4.6

Quantity of Analog Trunk PWBAs 0 X 8.2 = 0

Quantity of LTF CUAs 2 X 19.3 = 38.6

TOTAL LTF POWER (WATTS) = 116.6

4. DIGITAL TRUNK FRAME POWER (DTF) (DCO-E ONLY)

Quantity of T1 Interface PWBAs 5 X 11.2 = 56.0

Quantity of Message Assemblers 0 X 57.3 = 0

Quantity of DTF CUAs 1 X 67.4 = 67.4

TOTAL DTF POWER (WATTS) = 123.4

5. POWER RINGING & TEST FRAME POWER (PRTF) (DCO-E ONLY)

Power Ringing & Test Frame 1 X 92.0 = 92.0

TOTAL PRTF POWER (WATTS) = 92.0

Figure 2.1 SIEMENS STROMBERG-CARLSON DCO-E/DCO-SE

(Page 2 of 3)

6. AMAF/DATA COLLECTION FRAME (AMAF/CODC) (DCO-E & DCO-SE) WATTS

AMA Frame _____ X 495.0 =_____

CODC Data Collection Frame _____ X 523.0 =_____

TOTAL AMAF/DCF POWER (WATTS) = 0

7. COMMON EQUIPMENT FRAME POWER (CEF) (DCO-E) & DCO-SE)

Variable (Dependent on OEM Equipment Installed)

TOTAL CEF POWER (WATTS) = 0

8. UNIVERSAL POWER FRAME (DCO-SE ONLY) WATTS

Universal Power Frame (UPF) 1 X 92.0 = 92.0

Expanded Ringing CUA X 70.0 =______

*Universal Service CUA X 155.0 =______

*Universal Trunk/Service CUA 1 X 155.0 = 155.0

*Universal Trunk CUA 1 X 132.0 = 132.0

*Customber Trunk Group CUA 1 X 107.0 = 107.0

Quantity of DTMF Receiver PWBAs 2 X 19.3 = 38.6

Quantity of DTMF Sender PWBAs 2 X 5.0 = 10.0

Quantity of TMF Receiver PWBAs 2 X 8.5 = 17.0

Quantity of TMF Sender PWBAs 2 X 3.9 = 7.8

Quantity of Busy/Verification PWBAs 2 X 2.3 = 4.6

Quantity of Analog Trunk PWBAs 0 X 8.2 = 0

TOTAL UPF POWER (WATTS) = 564.0

9. REMOTE LINE SWITCH POWER (RLS)

Quantity of Lines 1000 x 3.2 CCS/L X 0.069 = 220.8

Quantity of Lines 1000 X 0.158 = 158.0

Quantity of Line CUAs 12 X 30.0 = 360.0

Quantity of RLG CUAs _____ X 31.0 =______

Quantity of SLC CUAs _____ X 158.0 =______

TOTAL RLS FRAME POWER (WATTS) =1644.8

*ONLY 3 CUAs TOTAL CAN BE EQUIPPED

Figure 2.1 SIEMENS STROMBERG-CARLSON DCO-E/DCO-SE

(Page 3 of 3)

10. REMOTE LINE SWITCH - 450 POWER (DC) WATTS

TYPICAL Basic RLS-450 (Maximum) = 1200

CUSTUMBER POWER (250W Maximum) = 0

TOTAL RLS-450 DC POWER TOTAL WATTS (Maximum) = 1200

RLS-450 Rated Ac Power Input (Typical) = 6000

(Based on typical cold weather heating plus maximum short term system load.)

11. SYSTEM DC POWER SUMMARY

1. DCO-E SYSTEM POWER

Total Common Control Frame Power =2400.0

Total Local Line Switch Power =1044.8

Total Line/Trunk Frame Power = 116.6

Total Digital Trunk Frame Power = 123.4

Total Power Ringing & Test Frame Power = 92.0

Total AMA/Data Collection Frame Power = 0

Total Common Equipment Frame Power = 0

TOTAL DCO-E SYSTEM DC POWER REQUIREMENTS =3776.8

TOTAL DCO-E DC BUSY HOUR LOAD (TOTAL WATTS/52.1 VOLTS) = 72.5 AMPS

12. DCO-SE SYSTEM POWER

Total Control & Maintenance Frame Power =2000.0

Total Local Line Switch Frame Power =1044.8

Total AMA/Data Collection Frame Power = 0

Total Universal Power Frame Power = 564.0

Total Common Equipment Frame Power = 0

TOTAL DCO-SE SYSTEM DC POWER REQUIREMENTS =3608.8

TOTAL DCO-SE DC BUSY HOUR LOAD (TOTAL WATTS/52.1 Volts) = 69.3 AMPS

FIGURE 3 REDCOM MDX

Quantity Multiply By Amps

MSU Shelves (One per 40 Lines) __________ 3.5 _______

Heat Dissipation (Watts) = 52.1 x DC Drain ________ = _______ Watts

150 Lines

Quantity Multiply By Amps

MSU Shelves (One per 40 Lines) 4 3.5 14

Heat Dissipation (Watts) = 52.1 x DC Drain 14 = 730 Watts

FIGURE 4 AT&T 5ESS SWITCH

(Page 1 of 2)

1. Basic (AM and CM) 55.76

2. No. of Disk Drive Units _____ x 1.30 Amps _______

3. No. of Switching Modules w 32Mb Memory _____ x 9.94 Amps _______

4. No. of MMSUs _____ x 0.20 Amps _______

5. No. of LUs _____ x 5.60 Amps _______

6. No. of TUs _____ x 0.18 Amps _______

7. No. of DCTUs _____ x 2.00 Amps _______

8. No. of GDSUs _____ x 0.61 Amps _______

9. No. of DLTUs _____ x 0.02 Amps _______

10. No. of DLTU Packs _____ x 0.12 Amps _______

SUBTOTAL _______

Additional Drains _______

TOTAL DC Drain _______

FIGURE 4 AT&T 5ESS SWITCH

(Page 2 of 2)

Heat

Dissipation

Per Frame Total Heat

Type of Frame Quantity (BTUs) Dissipation

Basic (AM and CM) ________ 9931.42 ______

No. of Disk Drives ________ 231.54 ______

No. of Switching Modules ________ 1770.41 ______

No. of MMSUs ________ 36.27 ______

No. of LUs ________ 997.42 ______

No. of TUs ________ 32.95 ______

No. of DCTUs ________ 356.22 ______

No of GDSUs ________ 108.05 ______

No. of DLTUs ________ 174.55 ______

TOTAL BTUs ______

FIGURE 4.1 AT&T 5 ESS SWITCH

(Page 1 of 2)

1 SM Office with 1000 Analog Lines,

12 Analog Trunks, and 192 Digital Trunk Circuits.

1. Basic (AM and CM) 55.76

2. No. of Disk Drive Units 4 x 1.30 Amps 5.20

3. No. of Switching Modules w 32Mb Memory 1 x 9.94 Amps 9.94

4. No. of MMSUs 11 x 0.20 Amps 2.20

5. No. of LUs 3 x 5.60 Amps 16.80

6. No. of TUs 4 x 0.18 Amps 0.72

7. No. of DCTUs 1 x 2.00 Amps 2.00

8. No. of GDSUs 3 x 0.61 Amps 1.83

9. No. of DLTUs 1 x 0.02 Amps 0.02

10. No. of DLTU Packs 8 x 0.12 Amps 0.96

SUBTOTAL 95.43

Additional Drains _______

TOTAL DC Drain 95.43

FIGURE 4.1 AT&T 5ESS SWITCH

(Page 2 of 2)

1 SM Office with 1000 Analog Lines,

12 Analog Trunks, and 192 Digital Trunk Circuits

Heat

Dissipation

Per Frame Total Heat

Type of Frame Quantity (BTUs) Dissipation

Basic (AM and CM) 1 9931.42 9931.42

No. of Disk Drives 4 231.54 926.16

No. of Switching Modules 1 1770.41 1770.41

No. of MMSUs 11 36.27 398.97

No. of LUs 3 997.42 2992.26

No. of TUs 4 32.95 131.80

No. of DCTUs 1 356.22 356.22

No of GDSUs 3 108.05 324.15

No. of DLTUs 1 174.55 174.55

TOTAL BTUs 17005.94

FIGURE 5 MITEL GX5000

D.C. DRAIN

EQUIPMENT QUANTITY MULTIPLY BY WATTS

First peripheral pair and Main

control (includes all features,

AMA, matrix and first cabinet) 1 460 460

Additional peripheral pair 96 ___

Additional cabinet 105 ___

Single Party line card (16 ckts) 10 ___

DS1 trunk card (2 spans) 29 ___

Universal line card (6 ckts) 9 ___

Total D.C. Drain Watts

Converted to AMPS (Watts/Battery Voltage) = Watts/52 = ____ Amps

Heat dissipation = _____ Watts or (3.41 X ____Watts) = ____ BTU

FIGURE 5.1 MITEL GX5000

Example System: 1008 lines, 96 Digital Trunks

EQUIPMENT QUANTITY MULTIPLY BY WATTS

First peripheral pair and Main

control (includes all features,

AMA, matrix and first cabinet) 1 460 460

Additional peripheral pair 2 96 192

Additional cabinet 1 105 105

Single Party line card (16 ckts) 63 10 630

DSI trunk card (2 spans) 2 29 58

Universal line card (6 ckts) 0 9 0

Total D.C. Drain 1,445 Watts

Converted to AMPS (Watts/Battery Voltage) = 1,445 Watts/52 = 27.7 Amps

Heat dissipation = 1,445 Watts or (3.41 X 1,445 Watts) = 4927 BTU

Figure 6 TRANSMISSION ELECTRONICS CURRENT DRAIN

48-Volt Battery Drain

Amperes Per Unit

Loop Extenders 0.075

1. Negative Impedance 0.035

2. Hybrid 0.035

3. Automatic Gain Control 0.080

4. Loop Extender/Repeater Combination 0.100

5. Automatic Gain Control

Loop Extender/Repeater Combination 0.200

1. D1 or D2 3.0

2. D3 (24 Channel) 0.7

3. D4 (24 Channel) 0.35

4. T1 Span Line 0.6

5. Station Carrier (1 Channel) 0.04

6. Station Carrier (Multi-Channel) Per Channel 0.1

7. Pair Gain Devices (Switching)

(See Notes 1 & 2 for Office End)

1. VF (1 Channel) 0.075

2. Digital (24 Channel) 1.7

1. Test Console (110V ac, 0.4A) 0.7

2. Remote Terminal 0.7

120V, 60Hz Load

Maintenance and Control Center Amperes Per Unit (Note 3)

Co-located with COE:

Video Display (CRT) 0.5

Printer (1200 Baud) 0.5

Remotely Located:

Teletypwriter (e/w 300 Baud Modem) 0.35

NOTES:

1. Refer to the manufacturer's data sheets for specific current drain

requirements.

2. Line concentrators or other pair gain devices incorporating switching

functions are generally locally powered at remote site.

3. Voltage: 95 to 128V ac - Frequency: 48 to 65Hz

Figure 7 ESTIMATING TELEPHONE BATTERY SIZES

8-Hour Ampere Hour Capacity Required

Number of Hours Final Cell Voltages

Reserve 1.75 1.80 1.85 1.88 1.90 1.95

1 2.2 2.5 2.8 3.2 3.5 5.0

2 3.2 3.4 3.7 4.3 4.7 6.2

3 4.0 4.3 4.7 5.2 5.6 7.5

4 4.9 5.1 5.6 6.1 6.5 8.6

5 5.7 6.0 6.5 7.0 7.4 9.6

6 6.5 6.8 7.3 7.8 8.2 10.6

7 7.2 7.6 8.1 8.7 9.1 11.6

8 8.0 8.3 8.9 9.6 10.0 12.6

9 8.8 9.1 9.6 10.4 10.9 13.7

10 9.5 9.9 10.4 11.4 12.0 15.0

Voltage (24 Cells) 42 43.2 44.4 45.1 45.6 46.8

EXAMPLES:

1. Required: The capacity of a 24-cell battery to handle a 3-hour load of 34.0 amperes to a limited voltage of 45 volts.

45/24 = 1.88

From the above chart, each ampere of load requires 5.2 ampere hours of capacity.

Total capacity required = 5.2 x 34.0 = 177 ampere hours. Select next larger catalog size.

2. Calculate the ampere hour reserve of an existing 24-cell, 480-ampere hour battery with the load increased to 69 amperes to a final voltage of 1.88 volts.

Formula: K = B/C

Where

K = 8-hour ampere hour capacity required for

each ampere of load.

B = Ampere hour capacity of existing battery.

C = Actual current drain of all equipment.

K = 480/69 = 7.0

On the chart, locate 7.0 in the 1.88-volt column

and to the left read 5 hours of reserve.

FIGURE 8 CHARGER CAPACITY

The battery charger has to supply power for operation of the COE. Its capacity should be great enough to carry the entire load, including peak power requirements, to avoid taking power from the battery. Additional capacity is required to recharge the battery after a power service interruption.

EXAMPLE:

Drain 66 Amps

Battery Discharged for 3 Hours and Recharged

in 12 Hours: 3 x 66 / 12 = 16.5 Amps

Calculated Charger DC Current Requirement 82.5 Amps

Rated Charger Capacity (as indicated in

Paragraph 3.4) 75 Amps

The charger capacity sizes commercially available include:

2 @ 75 Amps - Traditional arrangement with

load sharing between the two

chargers.

3 @ 50 Amps - Potential cost saving over

buying two larger units.

Potential operating cost

saving by operating only

two units.