Securitron MXD-62 - Manual (Page 4)

PN# 500-12800
Page 4
Rev. C, 2/09
Finally, the cover mounts utilizing the
binder posts and matching screws. Do not
mount the cover yet as you will want to
check adjustment of the proximity switch
array. Mounting the cover is the final
step when everything else is complete.
When you do mount the cover, the long
binder post inserts into the cover and goes
through the corresponding hole in the sub-
plate. See the drawing to the right. The
matching screw secures it. Note that the
screw affixes the binder post from the side
of the cover that includes the opening for the Magnalock face. This is so the blank head of the
post faces away from the door. This reduces the risk of tampering and looks better. If you have
an aluminum frame glass door with a blade stop, you will have to drill through holes
through the blade stop (or remove a small section) to pass the binder posts though for final
cover mounting.
3. WIRING THE MXD
The sole purpose of the MXD is to send an initiate signal to Securitron’s model XDT delayed
exit logic timer. The signal is furnished from the two flying leads attached to the proximity
switch array on the sub-plate. These two wires are closed when the door is in the normal closed
position and they open when the door is pushed open approximately one inch which takes up the
slack in the assembly provided by the MXD sex bolt. The leads should be pulled up into the
same hole you make in the sub-plate with the Magnalock cable. They connect to terminals “+”
and “IN” on the XDT circuit board (see EXD instructions).
4. ADJUSTING THE DOOR MOVEMENT STROKE
When you have finished wiring of the complete door installation, put the door through its
delayed exit sequence several times by slowly opening the door to initiate delay. The factory set
position of the proximity switch array should allow considerable door movement prior to the
delay starting. The benefit of this large movement (approximately 1”) is the avoidance of
false initiation through (for example) the door being rattled from the outside or moved by the
wind. The movement stroke can be reduced by loosening the screws that hold the proximity
switch array to the sub-plate and sliding the array farther from the door. Securitron
recommends that this be done only in special situations. Examples would be if the door will not
physically move far enough to reliably initiate delay without reducing the stroke because the
door is thicker than 1 3/4” and you have not added a spacer to the MXD sex bolt (see Section
2.3.1) or if you deliberately want to mechanically limit the amount of door movement because of
high security concerns for that door (you wish to avoid the possible insertion of a crowbar).
5. REDUNDANT OPERATION AND TAMPER PROOFING
The proximity switch array contains three proximity switches for the following reasons. Two are
wired such that if either switch de-energizes as the permanent magnet is separated from the
switch array, the delay initiate signal will be given. This provides redundant reliability of safe
egress operation as single component failure will not stop the MXD from allowing egress.
The third proximity protects against a certain type of tampering. It is wired such that if
another permanent magnet is brought near to it, it will initiate the delay. It is positioned so that
it never gets close enough to the permanent magnet pack on the door to trigger. The MXD
therefore includes a strong defense against tampering with its safety function. This function
should nevertheless be periodically tested by building management as maintenance of life
safety should be the paramount concern.
SUB-PLATE
CO
V
E
R
BINDER POST
SCREW
OPENING
FOR MAGNET