AT&T 3.0 manual Heavy Lightning Protection

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 trunks, do the following:

■Connect a 146A protector to the 147A protector, providing protection for an additional four trunks.

■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 2–4for 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.When you use the second 147A, you can connect the 146As in any combination, up to a maximum of three 146As per 147A.

2.For detailed installation instructions, see the documentation packaged with the protectors.

2-14Installing the Control Unit