AT&T 3.0 Telephone User Manual


 
AC Power and Grounding
Heavy Lightning Protection
For most surges, adequate protection is provided by meeting the previously
listed requirements. Additional protection is required when the customer is
located in a heavy lightning area.
Connect a 147A protector to the system to limit surges from the AC lines and
up to four CO trunks.
For systems with more than four CO
Connect a 146A protector to
for an additional four trunks.
trunks, do the following:
the 147A protector, providing protection
Connect up to three (maximum) 146A protectors to a 147A protector,
allowing a maximum of 16 trunks on one 147A protector.
For more than 16 trunks, add another 147A protector and continue
adding 146A protectors as needed. See Table 2–3 for various
configurations and Figure 2–4 for a typical 147A protector installation.
Table 2-3. Heavy Lightning Protection
Number of CO Trunks Required Protectors
1-4
147A
5-8
147A and a 146A
9-12
147A and two 146As
13-16
147A and three 146As
17-20
Second 147A
21-24
Second 147A and one 146A
NOTES:
1.
2.
When you use the second 147A, you can connect the 146As in any
combination, up to a maximum of three 146As per 147A.
For detailed installation instructions, see the documentation packaged with
the protectors.
2-14 Installing the Control Unit