AT&T 75 Wiring Manual page 63

provides automatic ground start (no ground start switches are needed). Each 574-5 unit can
accommodate up to five voice terminals used for emergency transfer service.
If loop start trunks are used for the emergency transfer stations, the 400B apparatus
mounting equipped with the Z1A Emergency Transfer Unit is recommended. Each Z1A unit
can accommodate up to six voice terminals used for emergency transfer service (see Note).
Note: One of the emergency transfer positions is occupied by the optional DID make-
busy trunk, if provided.
If there are no emergency transfer stations, the 400A apparatus mounting is recommended.
It is also recommended when more than one CAP is required and the emergency transfer
units are located in another CAP or outside the CAP.
If the number of analog stations required for emergency transfer service exceeds the
capacity of the CAPs, additional emergency transfer units should be ordered separately and
mounted on the wall near the CAP. Each wall-mounted emergency transfer unit requires an
additional CAP pass-through connection.
Z100-TYPE HARDWARE
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