ADTRAN 700A- 110-M-25 or 700A-66-B1-25 157BF Cut-Down Jack, 10B Emergency Transfer Unit ETU

INSTALLATION

Trunk Access Equipment

The trunk access equipment (TAE) consists of 700A-I 10-61-25 or 700A-66- B1 -25 (157BF) cut-down jacks, or equivalent, and up to four 10B Emergency Transfer Units (ETUs). The 10B ETU is shown in Figure 2-1.

700A- 110-M-25 or 700A-66-B1-25 (157BF) Cut-Down Jack

Trunk circuits that appear on the network interfaces are grouped by trunk type (Direct Inward Dialing [DID], Central Office [CO], or Tie) and punched down on the 700A jack. One 700A jack is required for each RJ21 X or RJ2GX network interface. The 700A-1 10-B1-25 jack has a 110-type cut-down field, and the 700A-66-B1-25 (157BF) has a 66-type cut-down field. It is important to note that most secondary wiring protectors (sneak current fuses) are compatible only with the 66-type jack.

10B Emergency Transfer Unit (ETU)

During a power failure or system outage, each 10B ETU provides contact closures for bypassing the switch and connecting up to five predesignated FCC registered single-line voice terminals to telephone company trunks. Connectorized cables (25-pair) connect the ETU to the 700A jacks, the system cabinets, and the Station Interconnect Panel. A modular plug-ended cord (part of octopus cable) connects control power (–48 V dc) from the system cabinet.

Screw terminals that connect to relay contacts which may be used for an external alerting device are also provided. The relay contacts close when a failure occurs. (Any alerting device and associated power unit with a dc current requirement less than or equal to 0.5 ampere may be used.) The ETU also controls a DID make-busy contact that connects to the last pair on the 700A jack. For a more detailed drawing of the 10B ETU, see Install Emergency Transfer Units (ETUs) in this part.

2-4