Securitron EXD - Manual (Page 3)

PN# 500-13350
Page 3 Rev. E, 11/11
The MXD is a kit which includes a housing that surrounds
the magnet body and conceals a proximity switch array.
Note: it is not compatible with the SAM shear aligning
Magnalock. A permanent magnet array is also part of the
kit and this mounts behind the strike plate so that a signal
is generated when the door is partially opened (the
distance between the permanent magnet array on the
door and the proximity switch array within the magnet
housing increases to a detection point). The door is
allowed to open a distance of about one inch by the
presence in the kit of a spring loaded sex bolt which has
an internal plunger that telescopes out when an attempt is
made to open the door. A person desiring to exit clears
the latch by activating the exit hardware and then moves
the door open approximately an inch at which point all the slack in the special sex bolt is taken
up. This movement is detected and the initiate signal is provided.
The SB-MXD (also not compatible with the SAM) operates the same way but the housing for the
magnet body is eliminated as is the permanent magnet array behind the strike plate. Instead,
the limited door movement permitted by the spring loaded sex bolt is detected by a furnished,
separately mounted magnetic door switch. This permits a more compact installation but is less
tamper proof.
Finally, where the latching exit hardware is of the mortise type
(rather than rim or vertical rod), Securitron’s LM series of
Latch Monitors may be used (assuming wires can be pulled up
the door frame). The Latch Monitor mounts behind the strike of
the mechanical exit hardware latch and detects when the latch
is withdrawn by the exit hardware. Withdrawal of the latch
initiates the delay. Compared to the MXD, the Latch Monitor is
much less tamper resistant but yields a very compact and low
cost installation.
Note that electronic access control cannot be integrated with
the initiate devices in this section because we can’t allow the
latch to be retracted from the outside to permit entry. If latch
retraction from the outside was possible, the delay could be
initiated from the outside for unauthorized entry and this
defeats the purpose of the system.
2.3 LOGIC TIMER
All logic and timing functions for the EXD system are performed by a special timer (Model XDT-
12 or XDT-24) implemented on a circuit board. The board is supplied from Securitron in a
locking surface mount enclosure which includes a Sonalert on its cover. The part number for the
complete assembly (board + enclosure) is BA-XDT-12 or BA-XDT-24. Alternately Securitron
offers a flush mount enclosure (FA-XDT-12 or FA-XDT-24).
The XDT timer is a powerful microprocessor device which not only performs the logic functions
necessary to meet the different codes, but provides many optional features that enhance the
security and safety aspects of the installation. See Section 7 for the details of optional
functions.
2.4 RESET DEVICE
Once the door has been released, it will remain in this state until "manually" reset. In the EXD
system, this is accomplished by a normally closed switch opening then closing once more
(momentary action). The switch is supplied as part of Securitron's MK series mortise keyswitch
which is mounted at the door so that the door will be inspected by a responsible individual prior
to reset. The MK requires the on site addition of a 1 1/4" or 1 1/8" mortise cylinder which
activates the switch. Typically, the cylinder is furnished by a local locksmith and is keyed into
the facility keying system. The standard MK is furnished on a single gang outlet box cover. The
MKN version is furnished on a 1 3/4" plate for narrow style door frames. A red/green bicolor
LED is included.