/

130Other Consideratiaons

130.1Electrical Noise Generators

Certain equipment, such as welding machines,

thyrister-driven power supplies, large electrical motors, etc. generate electrical noise. As a stored program machine the

Electra-616 System is vulnerable to this noise. When this type of machine is present at an instahation, the following precautionary steps are urged:

1.

Locate

KSU,

telephone

sets,

and cabling

away from

 

these machines.

 

 

 

 

2.

If cables

must

pass near

these

machines,

use shielded

 

cabIe with the shield grounded.

 

 

140 Specifications

140.1System Capacity

 

The Electra-616 system capacity is as follows:

CO/PBX

Lines

6max.

Intercom

Paths

2 max.

Internal

and External Paging Path

1 max.

Station

Sets

16 max.

BLF

Consoles

2 max.

Door

Phones

2 max.

140.2Cabling Requirements

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a;

3

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._>.

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,’

:;

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:

x

.k.

7,

3. Ensure all machines

of

this

type are well-grounded to a

separate ground

to

minimize

noise interference.

130.2 Pre-installation

Site

Survey

Since a pre-installation survey is generally required

to plan for application and installation, a check of the matters covered so far in this section at this time will pre- vent later problems.

130.3 Additional Equipment

In addition to electronic station equipment and the KSU and their contents, other equipment is required. This includes cables, modular connecting jacks, quick- connect blocks (or smimlar apparatus), etc. This additional equipment must be locally supplied.

1.Cabling required for Key Telephone Sets, BLF Con- soles, Door Phones is as follows:

1)Required Cable

-Key Telephone Set: Twisted 2-pair cable

-

BLF

Console:

Twisted 1-pair cable

-

Door

Phone:

Twisted 1-pair cable

2)Maximum Loop Resistance and Cable Length at 24AWG

-Key Telephone Set: 40 ohms, 700 ft. (21Om)

- BLF

Console:

40 ohms,

700

ft.

(21Om)

- Door

Phone:

40 ohms,

700

ft.

(210m)

3)Maximum Cable Length at 22AWG

*Key Telephone Set: 1,150 ft. (35Om)

- BLF

Console:

1,150

ft.

(35Om)

- Door

Phone:

1,150

ft.

(35Om)

2.BLF Consoles require a local power supply (provided with each unit), which plugs into a 117V AC outlet. The cable provided with these units is 6 feet in length.

Page 100-2

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NEC 616 manual Co/Pbx