3COM 3CNJ100 User Manual

Installation Guide

NJ100 Network Jack

3CNJ100
4-port 10/100 Mbps Unmanaged
Ethernet Switch

http://www.3com.com/
http://www.3com.com/productreg

09-2141-000
Published September 2001

3Com Corporation
Santa Clara, California

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5400 Bayfront Plaza

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95052-8145

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U.S.A.

Copyright © 2001 3Com Corporation. All rights reserved. No part of this
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Contents

About the Network Jack 2
Before You Begin 6
Obtaining Optional Components 7
Installing the Network Jack 8

Setting up the Power Supply 10

Using an Integrated Switch with Power Over
Ethernet 10

Using a Multi-port Ethernet Power Supply 10
Using a Single-port Ethernet Power Supply 12

Using the 3Com Local Power Supply 12
Setting the Power Over Ethernet Dip Switches 13
Installing the Adapter Plate and Pass-Through Ports 15
Planning the Installation 17
Setting up the Network Cabling at Your Site 19
Connecting the Network Jack to the Network 19
Mounting the Network Jack 22
Connecting the Local Power Supply (Optional) 23
Connecting Devices to the Network Jack 23

Checking the LEDs 24
Troubleshooting the Network Jack 24
Specifications 26

Contents

Contacting Technical Support 28

One-Year Free Installation Support 28
Online Technical Services 29
World Wide Web Site 29
3Com Knowledgebase Web Services 29
3Com FTP Site 30
Support from Your Network Supplier 30
Support from 3Com 31
Returning Products for Repair 31

3Com Corporation Limited Warranty 33
FCC Class A Verification Statement 37
FCC Declaration of Conformity 37

Installation Guide

The 3Com Network Jack is a 4-port, unmanaged Ethernet switch
that fits into any standard electrical wall outlet or data port
opening.

The Network Jack brings switching capabilities to any single port
on an Ethernet network by allowing up to four networking
devices, such as computers, printers, Voice Over IP (VoIP)
telephones, and scanners, to be connected to the network via
one Ethernet port. Optional connectors are also available that
allow up to two additional devices to be connected to separate
network segments through the same Network Jack.

The Network Jack needs no software to operate and little or no
configuration. All ports feature 10/100 Mbps auto-negotiation,
which configures the Network Jack for 10 Mbps or 100 Mbps
connections automatically.

Power to the Network Jack can be provided one of the following ways:

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Over the network via an integrated switch that supports
Power Over Ethernet; specifically, a switch that is compatible
with Capacitive Power Discovery Process (24V or 48V) or IEEE

802.3af-compatible Power Over Ethernet. Power Over
Ethernet, also known as in-line power, is a feature that
provides power onto an Ethernet cable, allowing a device to
receive both data and power from the same network cable.

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Over the network via an optional single-port or multi-port
Ethernet power supply. See “Setting up the Power Supply”
on page 10 for more information.

■

Locally via an optional local power supply. See “Using the
3Com Local Power Supply” on page 12 for more information.

1

Installation Guide

About the Network Jack

The following diagram shows the front view of the Network Jack.

2

1

2

3

4

1

3

4

5

2

About the Network Jack

1 Switched ports Allow up to four devices to be connected to

the network.
Port number 1 is also a power-forwarding port;

it can be used with any standard networking
device as well as to power a VoIP telephone on
a network that uses IEEE 802.3af-compatible
Power Over Ethernet.

2 Slot for adapter

plate

Can be fitted with an adapter plate, which
can be installed with up to two pass-through
ports.

3 Adapter plate

with installed
pass-through
port connector

Can be used for voice or other networking
applications. The port bypasses the
functionality of the switch, allowing you to
set up a connection to a separate network
segment or to connect to an analog or digital
PBX telephone.

The adapter plates are available from 3Com.
However, you must purchase the connectors
from the manufacturer. See “Installing the
Adapter Plate and Pass-Through Ports” on
page 15 for more information.

4 LEDs

Indicates network connection status.

Indicates power status.

5 Power socket Can be used to power the Network Jack with

a local power supply (available for purchase
from 3Com); required if your network does
not support Power Over Ethernet.

3

Installation Guide

The following diagram shows the back view of the Network Jack.

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2

1

3

4

About the Network Jack

1 Ethernet uplink

port

Connects the Network Jack to the network.
Make sure the port on the network switch

to which the Network Jack is connected is
configured as a standard MDI-X port.

2 Slot for adapter

plate

3 Adapter plate

with installed

Can be fitted with an adapter plate, which can
be installed with up to two pass-through ports.

Connects the installed pass-through port to

the network.
pass-through
port connector

4 Dip switches Determine the type of Power Over Ethernet

(Capacitive Power Discovery Process 24V or

48V or IEEE 802.3af) the Network Jack uses.

Setting the dip switches is required only if your

network supports Power Over Ethernet, or if

you are using a multi-port Ethernet power

supply. See “Setting the Power Over Ethernet

Dip Switches” on page 13 for instructions.

5

Installation Guide

Before You Begin

Before you begin installation, register your product at:
www.3com.com/productreg.

The Network Jack is available in single- and 20-packs. Before you
begin the installation, make sure you have the following items,
which are included with the Network Jack:

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6x32 screws (2 per Network Jack) for mounting the
Network Jack to the wall or office cubicle.

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RJ-45 coupler cable (1 per Network Jack) for connecting
the Ethernet cable from the network to the Network Jack
(required only if your network cable is terminated with a
female RJ-45 connector).

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Installation guide (1 per package).

Additionally, the following items are shipped with the single pack:

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Adapter plates for installing connectors to use as pass­through ports. The adapter plates accommodate connectors
from suppliers including:

■

Panduit (RJ-45 and RJ-11)

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Avaya (RJ-45 and RJ-11)

NOTE: The connectors for the adapter plates must be

purchased from the manufacturer. For a list of supported
connectors, go to www.3com.com/.

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Adapter plate screws (2) for mounting the adapter plate to
the Network Jack.

6

Obtaining Optional Components

Obtaining Optional Components

The Network Jack works with the following optional components,
all of which are available from 3Com. Order online at
www.3com.com or by calling 1-877-949-3266.

Component Purpose 3C Number(s)

Adapter plates For installing pass-through port

connectors of your choice that allow
a direct connection to another
network segment or for connecting
an analog or digital PBX telephone.

Extension ring For ensuring that the Network Jack

is properly mounted to a cubicle;
required if the cubicle opening:

■

Has a depth of fewer than

1.5 inches.

■

Does not support the NEMA-

WD6 standard.

■

Does not have pre-drilled

screw holes for standard

mounting.

Single-port
Ethernet power
supply

Multi-port
Ethernet power

For providing Power Over Ethernet
to locally power a single Network
Jack.

For providing Power Over Ethernet
to power up to 24 Network Jacks.

supply

Local power
supply

For locally powering a single
Network Jack; required if your
network does not support Power
Over Ethernet.

3CNJAP-PA-20
3CNJAP-AV-20

3CNJEXTRING

3CNJPSE

3CNJPSE24
3C10220
3C10222

3CNJPSL

7

1

2

3

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5

6

7

Installation Guide

Component Purpose 3C Number(s)

VoIP telephone
power cable

Network Jack
Tester

For powering a VoIP telephone on a
network that uses Capacitive Power
Discovery Process-compatible Power
Over Ethernet.

For verifying the Network Jack
installation; useful if installing
multiple Network Jacks.

Check the 3Com
web site

3CNJTESTER

Installing the Network Jack

Installing the Network Jack consists of the following steps:

Set up the power supply (page 10).

Set the Power Over Ethernet dip switches (page 13;
optional, required only if your network supports Power
Over Ethernet or if you are using a single-port or multi-port
power supply).

Install the adapter plate and pass-through ports (page 15;
optional).

Plan the installation (page 17).

Set up the network cabling at your site (page 19).

Connect the Network Jack to the network (page 19).

Mount the Network Jack to the wall or office cubicle
(page 22).

8

8

9

Installing the Network Jack

Connect the local power supply (page 23; optional) not
required if your network supports Power Over Ethernet or
if you are using a single-port or multi-port power supply).

Connect network devices to the Network Jack (page 23).

The following diagram displays an overview of the recommended
installation, where the Network Jack is being connected to an
Ethernet network cable that is terminated with a female RJ-45
connector. Detailed installation instructions are included in the
sections that follow.

Wall

To wiring
closet

Network
cable

1

2

3

4

RJ-45
coupler cable

9