4.2 Door Holder Applications
In a typical door holder application, the door holder power must be released to close all fire doors under
the following conditions:
Any active alarm condition.
AC power is no longer present (to conserve backup battery power).
To close the fire doors in these situations, wire a normally closed relay contact from the fire alarm control
unit in series with the auxiliary power to the door holders.
The circuit shown in Figure 4-8 will provide up to 3 amps of door holder current. The power in this
example is released when AC power is off for 30 seconds or more, or when the relay from the fire alarm
control unit opens. See Section 1.1 for a description of the auxiliary power options, and Section 5.1.2 for
information on choosing the options.
Figure 4-8. Door Holder Wiring Example