Secondary Protection
Secondary Protection
Secondary protectors (stand alone units or integrated into strip protectors and UPSs) are
adjunct devices used to enhance the protection level of customer premise equipment
(CPE). Due to the inadequate level of protection designed into CPE, secondary protectors
often are required to prevent premature failure of equipment exposed to environmental
hazards (Figure 3.38).
Customer
Premise Equipment
Primary
Protector
Line
Impedance
Phone
Tip
P
S
Ring
Fax/Modem
Network
Interface
Secondary
Protector
Figure 3.38 CPE Secondary Protection
Protection Requirements
Secondary protectors should be able to withstand overvoltages that can exceed 800 V and
surge currents up to 100 A. Figure 3.39 illustrates a SIDACtor device selected because the
associated peak pulse current (IPP) is sufficient to withstand the lightning immunity tests of
TIA-968 (formerly known as FCC Part 68) without the additional use of series line
impedance. Likewise, Figure 3.39 illustrates a fuse selected because the amps2time (I2t)
rating is sufficient to withstand the lightning immunity tests of TIA-968, but low enough to
pass UL power cross conditions.
F1250T
Tip
P3203AB
To CPE
or
Equipment
P3203AC
Ring
F1250T
Figure 3.39 CPE Protection
© 2002 Teccor Electronics
3 - 31
http://www.teccor.com
+1 972-580-7777
®
SIDACtor Data Book and Design Guide
TECCOR [ TECCOR ELECTRONICS ]
