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