P1200S Teccor Electronics, P1200S Datasheet - Page 102

• Manufacturer Part Number: P1200S
• Description: solid state crowbar devices
• Manufacturer: Teccor Electronics

High Speed Transmission Equipment
Figure 3.16 T1/E1 Overview
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[phone]
Central Office
T1 Transceiver
TX Pair
RX Pair
T1/E1 Circuit Protection
T1/E1 networks offer data rates up to 1.544 Mbps (2.058 for E1) on four-wire systems.
Signal levels on the transmit (TX) pair are typically between 2.4 V and 3.6 V while the
receive (RX) pair could go as high as 12 V. Loop powering is typically ±130 V at 60 mA,
although some systems can go as high as 150 V. (Figure 3.16)
Protection Circuitry
Longitudinal protection is required at the Central Office Terminal (COT) interface because of
the ground connection used with loop powering. (Figure 3.17) Two P1800SC MC SIDACtor
devices provide overvoltage protection and two F1250T TeleLink fuses (one on Tip, one on
Ring) provide overcurrent protection. The P1800SC MC device is chosen because its V
is compliant with TIA-968 regulations, Section 4.4.5.2, “Connections with protection paths
to ground.” These regulations state:
Line powered DLC Four-wire,1.544 Mbps/2.048 Mbps
Approved terminal equipment and protective circuitry having an
intentional dc conducting path to earth ground for protection purposes at
the leakage current test voltage that was removed during the leakage
current test of section 4.3 shall, upon its replacement, have a 50 Hz or
60 Hz voltage source applied between the following points:
The voltage shall be gradually increased from zero to 120 V rms for
approved terminal equipment, or 300 V rms for protective circuitry, then
maintained for one minute. The current between (a) and (b) shall not
3000 ft
a. Simplexed telephone connections, including Tip and Ring, Tip-1
b. Earth grounding connections
and Ring-1, E&M leads and auxiliary leads
Line Regenerator
3 - 14
6000 ft
SIDACtor
Line Regenerator
®
Data Book and Design Guide
© 2002 Teccor Electronics
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