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FIG. 3: WIRING WITH MAGNETIC LOCK ONLY
12-28 VDC
POWER
SUPPLY
+
-
MAGNETIC LOCK
+
-
+
-
AL-85851
MATCH POWER
SUPPLY VOLTAGE TO
MAGNETIC LOCK
VOLTAGE
IN+ D VICE
C1 NC1 NO1
Note that how positive power to the lock connects through the terminal block “IN+” and
“DEVICE”. These two terminals constitute an internal field effect transistor which does the
actual switching. If power to the XMS was somehow interrupted, the field effect transistor
would automatically open (releasing power to the lock). This makes the
AL-85851
“fail
safe”. Note: never use the REX relay contacts to switch the magnetic lock. These
contacts only have enough capacity for signaling; they cannot reliably switch magnetic lock
current.
If you need to integrate a controlled entry unit such as a digital keypad, use a set of NC
contacts from the entry unit to break the wire between “DEVICE” and magnetic lock “+” to allow
the entry unit to release the lock.
3.3 SHUNTING AN ALARM POINT
This technique is for installations where the door is connected to an alarm system and that if
the door opens without the
AL-85851
having been activated, an alarm signal should result.
When the
AL-85851
is employed to open the door, the alarm signal should be shunted.
FIG 4: WIRING TO SHUNT ALARM SYSTEM ON DOOR
DOOR
SWITCH
TO ALARM PANEL
DOOR
SWITCH
TO ALARM PANEL
ALARM SIGNAL WHICH IS
CLOSED WHEN DOOR IS CLOSED:
OPENS TO ALARM
ALARM SIGNAL WHICH IS
OPEN WHEN DOOR IS CLOSED:
CLOSES TO ALARM
IN+ DEVICE
C1 NC1 NO1
IN+ DEVICE
C1 NC1 NO1
The alarm system will be connected to a door switch or other detector at the door via two wires.
You will need to determine if this “loop” is closed when the door is closed and opens when the
door opens or is open when the door is closed and closes when the door opens. Correct wiring
to shunt the alarm is shown in Figure 4 for either instance. You utilize the “REX” relay contacts
for this shunting while the lock control relay contacts continue to release the magnetic lock.
3.4 INTEGRATION WITH ACCESS CONTROL SYSTEM
An access control system permits entry (generally from a card reader) and will also often act as
an alarm system if a door is forced. To integrate with the
AL-85851
and a magnetic lock, the
access system should have a two-terminal REX (request to exit) input. When this input is
closed, the access system will operate its lock control relay to release the lock and will not
create an alarm signal as it will consider the exit event a “legal” one. Wiring is shown in Figure
5. Note that with this wiring method, the lock control terminals of the
AL-85851
directly break
power to the magnetic lock as do the access system contacts. This is called “double break”
wiring. It enhances safety
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