American Fibertek N-TAH - Manual (Page 10)

10
Note: the electrical connection to the alarm inputs are to be connected only to dry
(relay) contact closure devices, and must not be directly connected to any external
power or ground source. Directly connecting either terminal of the alarm input to any
voltage source or external ground may damage the N-TAH.
Connecting a supervised contact
In supervised contact mode a 1K resistor is connected in series with the contact closure.
This resistor should be located at or close to the contact device, so that short circuits
and open circuits across the contact lines will be detected. A valid contact closure will
be registered only when the resistance across the contact input lines is measured to be
1K ohm.
Connecting an aux output
The contact blocks have three terminals which are used for the aux contact out function
The contact outputs are form C contact closures.
To connect an external device to an aux contact out on the N-TAH, use two wires, 16-28
AWG in size. Strip about ¼” of the insulation from the end of the wires before inserting
them into the terminal blocks. Tighten the terminal screws to secure the wires in the
terminal block.
Aux Contact Out
When an output is not active, the Common terminal will be electrically connected inside
the N-TAH to the Normally Closed terminal. When the output becomes active, the
connection between the Common terminal and the Normally Closed terminal will be
broken, and a connection will then be made inside the N-TAH between the Common
terminal and the Normally Open terminal.
The Aux Output terminals are electrically isolated from the N-TAH and from each other,
and can be safely connected to external power sources or grounds.