Clear-Com EB7-4W Installation Guide
EB7-4W Module
Clear-Com’s EB7-4W 4-Wire Option module can be added to the KB-702, KB702GM, KB-701, and HB-702 products. This option allows the speaker or
headset station to be oper ated over l onger distances than are possible with a
standard Clear-Com intercom line. This option can also be used to connect
with fiber optic transmission equipment. The EB7-4W 4-Wire Option module
connection is a transformer-isolated, audio-only connection and does not
convey the call signal. The module also requires local powering.
Two-channel stations can have two separate 4-wire connections with this
option. The Channel Switch on the front panel selects which channel is
connected.
Installation
The EB7-4W plugs onto one- or two-channel speaker or headset stations as
illustrated in
KB/HB-Series
INSTALLATION INSTRUCTIONS
Figure 1.
Retaining
Screws
P2 Must be
installed if
no option
View from top
of KB-702
Channel A
Connection
EB7-4W
Option
Power
Connection
4-Wire
Option
1 2 3
Figure 1: Installation Diagram
Channel B
Connection
Front Panel
PN 810382Z Rev. 1 1 © Clear-Com Communication Systems
KB/HB-Series EB7-4W Module Clear-Com Communication Systems
Use the following steps to install the EB7-4W Option Module:
1. Remove the two screws from the station’s main circuit board and replace them with the supplied jackscrews.
2. Remove plugs P1 and P3. Retain these plugs for possible fu ture use.
3. Plug the EB7-4W Option onto the main circuit board where P1 and P3 were plugged.
4. Fasten the EB7-4W in place with the two screws removed in step 1.
Powering the Station
When the EB7-4W is installed, the speaker or headset station requires local
power, which can be obtained from the following sources:
20-30VDC
A suitable DC source is the Clear-Com 400067Z 30V 500mA AC-DC
converter.
14-20VAC
A suitable AC source is a doorbell transformer. This can be fitted in a
separate box that will contain the power-line connection and the low-voltage
output can be routed to the connector on the EB7-4W circuit board.
Note: Different types of doorbell transformers are commonly available at
hardware stores. Ensure that the output voltage is suitable for use with
the EB7-4W.
Warning: Always follow local electrical codes. Do not install mains wiring in
the same electrical box as the speaker or headset station.
Connect the two wires from the power source to the two-position, plug-on
terminal strip supplied with the 4-Wire Option. Plug this conn e cto r on to the
EB7-4W circuit board as shown in
Figure 1.
PN 810382Z Rev. 1 2 © Clear-Com Communication Systems
Clear-Com Communication Systems KB/HB-Series EB7-4W Module
A
A
ut
B
B
ut
n
Wiring the 4-Wire Module
The intercom line connector on the main circuit board does no t function when
the EB7-4W is installed. Instead, the 4-wire intercom connections are made to
the connectors on the EB7-4W circuit board. For each channel, “Audio Out”
and “Audio In,” pairs are provided. Both are balan ced, 600-ohm con nections.
An optional jumper can be installed if the receive signal is noisy. This adds a
resistive termination to the receive Audio In signal, red ucing the level by 6 to 8
dB. Typical wiring is as shown in
Pin 1
Pin 1
Figure 2.
Channel
Audio O
Optional Receive Jumper
Channel
Audio In
Channel
Audio O
Optional Receive Jumper
Channel
Audio In
Power I
Figure 2: Typical EB7-4W Wiring
• 4-Wire Intercom Line Connections: When the EB7-4W is used, the
intercom connections to each channel are made to five-terminal plugon connectors on the EB7-4W circuit board instead of to th e conn ecto r
on the KB-701 circuit board. The connections for each pin are visible
on the circuit board when the connector is unplugged. The connector
pinout for each channel is as follows:
• Pins 1 and 2—Intercom Audio Input (audio to the speaker or
headset)
• Pin 3—Optional Receive Jumper (used if receive signal is noisy)
• Pins 4 and 5—Intercom Audio Output (audio from the
microphone).
When the KB-702 is used, the 4-wire intercom connection must be
made to the Channel B connector.
© Clear-Com Communication Systems 3 PN 810382Z Rev. 1
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