Install the 808A Emergency Transfer Panel

Install Emergency Transfer Units and Associated

Telephones

Install Emergency Transfer Units and

Associated Telephones

Emergency transfer capability is provided by a transfer unit mounted on the wall next to the trunk/auxiliary cross-connect field.

Analog telephones can be used for emergency transfer. The 500-and 2500-type telephones can also be used as normal extensions. Emergency transfer capability may be provided on Central Office (CO) trunks.

The following transfer units are available:

■The 808A Emergency Transfer Panel provides emergency trunk bypass or power-fail transfer for up to five incoming analog Central Office (CO) trunk loops to five selected private branch exchange analog single line telephones. When a power failure or other system problem interrupts service, the sets are automatically and directly connected to the Central Office trunks and are available for emergency use outside the private branch exchange service environment.

When a telephone connected to the 808A goes off-hook during bypass, circuitry inside the panel places signalling on the Central Office (CO) trunk causing the Central Office (CO) to return dial tone. Each 808A bypass circuit can be switched to either loop start or ground start signalling.

■The 574-5 power transfer unit serves up to five power failure transfer telephones. The unit provides automatic ground start.

At the cross-connect field, the transfer units are connected to a yellow terminal row/connecting block in the trunk/auxiliary field. The units are powered (-48VDC) from the EM TRANS RELAY PWR terminals. Refer to Figure 9-6for pinout information. There are seven EM TRANS RELAY PWR terminal pairs to provide power to up to seven transfer units.