ALCO AL-85851 User manual
ALCO Sales & Service Co.
Tel 800.323.4282 www.alcosales.com
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© Copyright, 2011, all rights reserved Page 1
AL-85851 EXIT MOTION SENSOR
INSTALLATION AND OPERATING INSTRUCTIONS
1. DESCRIPTION
The AL-85851 is a passive infrared motion detector specifically designed to release a magnetic
lock from the inside for free egress. Unlike burglar alarm type detectors, the AL-85851
special features are appropriate to this use. The lock control function is fail safe so that
the magnetic lock will safely release if power is cut to the detector. A relay is also present
to send a REX (request to exit) signal to an access control system (if one is present) and
therefore shunt an alarm report. A time extension feature avoids the problem of the unit
resetting if a person momentarily stops moving just before exit. Tight control of the exit
detection pattern allows maximum security from the outside and avoidance of inadvertent
activation from the inside.
Since egress from a magnetically locked door can be a safety issue, make sure you are
complying with local building codes. Contact your building and/or fire prevention
department.
2. PHYSICAL INSTALLATION
2.1 PLACEMENT OF THE UNIT
The AL-85851 is intended for indoor use only. It is positioned with respect to the inside of the
door so that its detection pattern will “see” a person approaching the door while maintaining
good security from the outside. There are different options as to where the unit is placed
depending on variables in the application.
FIG. 1: PLACEMENT OPTIONS FOR THE SENSOR
FOR TRAFFIC CONTROL
APPLICATIONS, MOUNT THE
SENSOR IN THE CENTER OF
THE DOOR WITH THE
PATTERN AS SHOWN
FOR SECURITY
APPLICATIONS, THE
PATTERN SHOULD SWEEP
ACROSS THE EXIT DEVICE
BUT MISS THE BOTTOM OF
THE DOOR. THE SENSOR IS
POSITIONED BEYOND THE
HINGE SIDE OF THE DOOR
WHEN A DOORKNOB IS
PRESENT IN A SECURITY
APPLICATION, THE
PATTERN CAN BE MADE
MORE NARROW THE SENSOR CAN BE
POSITIONED AT THE
SIDE FOR SECURITY
APPLICATIONS ON
DOORS AT THE END
OF CORRIDORS
The simplest method of placing the unit is for traffic control applications. A traffic control
application is one where you do not expect any attempt at breaking in from the outside. The
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unit is simply centrally positioned above the door with the pattern covering the door (setting the
pattern is addressed later in this manual).
For security applications, you will set your position to defend against someone activating the
detector from the outside. This can be done by inserting a heated object under the door. To
deal with this threat, the unit is positioned above and outside of the door hinges with the pattern
adjusted so that it sweeps across the door but does not detect the bottom of the door. If the
door includes an exit bar, the pattern must be broad as a person’s approach to the door is
variable. If it includes a door knob or lever handle, the pattern can be adjusted more
narrowly. A final option for security applications is to position the unit at the side of the door
so that it sees across the door. This can be used for doors at the end of corridors. You would
not want to employ this approach for non corridor doors as the door would be released by
someone walking near it (maximum detection range is 20-25 ft.) Side of door mounting has the
disadvantage of greater exposure to vandalism but defends against objects being inserted under
the door and provides excellent coverage along the full width of the door. Note that for the end-
of-corridor application, the unit can be positioned on the same wall plane as the door or on a
wall which is next to the door and perpendicular to it. You have the choice because the pattern
can be adjusted a full 90 degrees with respect to the sensor’s mounting plane.
2.2 FIXING THE UNIT TO THE WALL
First, locate the screw on the end of the unit and loosen it. This permits you to remove the
cover. The appearance of the interior is shown in Figure 2. Note that the interior electronics is
mounted on a rotating barrel which is locked by the “Barrel Locking Screw” shown in Figure 2.
Loosen this screw and rotate the barrel fully upward so that you can remove it. This leaves you
with the back piece and you will see two slotted holes for physical mounting and a choice of two
wire entry points (also shown on Figure 2). Most installers prefer to pull the cable through the
wall first and then mount the unit. If you’re not sure of your wire count for the cable, consult
the next section at this time but completion of physical installation consists only of screwing the
back piece to the wall and pulling the cable through one of the wire entries. Then you will
replace the barrel assembly and attach the wires to the screw terminals.
FIG. 2: AL-85851 OVERVIEW
IC
AB
LED FAST
IN+ DEVICE C1 NC1 NO1
BARREL LOCKING
SCREW
+-
12-28 VDC
POWER
LOCK CONTROL REX RELAY
WIRE
ENTRY
HOLES
AIMING
SCREWS
SENSITIVITY
JUMPER
LED LOGIC
JUMPER
TIME SET
JUMPER
BI-COLOR
LED
3. WIRING
3.1 INPUT POWER
To power the unit, filtered and regulated DC voltage between 12 and 28 volts should be applied
to the power input terminals (see Figure 2). This connection should be permanently made to
the power supply rather than switched through some other device. The AL-85851 should
receive constant power. Make sure you observe correct polarity with this connection. If you
reverse the input power polarity, the unit will not be damaged but will appear to be dead.
Power consumption for the XMS is approximately 20 mA.
3.2 WIRING WITH MAGNETIC LOCK ONLY
This is the simplest application which releases the magnetic lock from the inside for free egress
but is not concerned with shunting any alarm point at the door. It is shown in Figure 3.
INPUT
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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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and reliability as if the access system experiences a fault, the XMS still allows safe egress. If the
access system is not monitoring the door, connection to the REX input is not required. In that
case, make all other connections as shown in Figure 5 except the REX input.
FIG. 5: WIRING WITH AN ACCESS CONTROL SYSTEM
12-28 VDC
POWER
SUPPLY
+
-
MAGNETIC LOCK
+
-
+
-
XMS
REX
INPUT
CNC
ACCESS SYSTEM LOCK CONTROL RELAY
USE 1/2 SECOND TIME
SETTING WITH ACTIVE REX
(SEE SECTION 5)
IN+D VICE C1 NC1 NO1
FIG. 6: WIRING WITH “GENERIC” PUSH BUTTON AND TIMER
12-28 VDC
POWER
SUPPLY
+
-
MAGNETIC LOCK
+
-
+
-
XMS
REX
INPUT
CNC
ACCESS SYSTEM LOCK
CONTROL RELAY
TM-8L
TIMEMATE
CNC
YEL
RED GRN
WHT
BLK
PUSH BUTTON
NO
USE 1/2 SECOND TIME
SETTING WITH ACTIVE REX
(SEE SECTION 5)
IN+D VICE C1 NC1 NO1
3.5 “ACCESS CONTROLLED EGRESS DOOR”
In some jurisdictions, the combination of a magnetic lock, access control system and exit
detector such as the AL-85851 can be considered an “access controlled egress door”. The
applicable section of the Life Safety Code calls for a redundant means of exit in the event of a
problem with the detector. This is typically a push button located 40-48” above the floor and
within five ft. of the door. Pushing the button will directly release power to the magnetic lock
and the lock shall remain released for 30 seconds. This can be accomplished with any of the
push buttons and the model TM-8L timer. Figure 6 shows proper wiring.
ALCO also manufactures a line of push buttons with integrated timers (AL-85852).
These are easier to use with the AL-85851 to satisfy the code requirements for access
controlled egress doors. Figure 7 shows wiring with the integrated push button/timers.
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FIG. 7: WIRING WITH INTEGRATED PUSH BUTTON AND TIMER (AL-85852)
12-28 VDC
POWER
SUPPLY
+
-
MAGNETIC LOCK
+
-
+
-
AL-85851
REX
INPUT
CNC
ACCESS SYSTEM LOCK
CONTROL RELAY
RED
GRN
BLK
USE 1/2 SECOND TIME
SETTING WITH ACTIVE REX
(SEE SECTION 5)
IN+D VICE C1 NC1 NO1
AL-85852
PUSH BUTTON
WHT
4. BASIC OPERATION
When the AL-85851 is first powered, its LED will flash twice quickly every second for
about 40 seconds. This is a self test and also permits the AL-85851 to adjust itself
to the thermal environment that it “sees”. After this start up period, the LED will stay
green. If the self test fails during the start up period, the LED will begin to flash at four times
per second. This failure indication will continue indefinitely. If you see it, de-power the unit
for about 30 seconds and then re-power it. If the failure indication occurs again, replace the
unit.Duringtheselftestperiod the unit’s control outputs are in their “normal” conditions
(lock control-conducting; REX-relay deenergized).
In the event of a very brief power outage, the unit will not self test for 40 seconds but will
undergo a self test of 10 seconds before resuming normal operation. Note that the self test on
power up feature of the unit is the main reason why the AL-85851 must receive constant
power.
With the jumpers in factory set condition and the unit past its self test, it will detect moving
objects at a different temperature than ambient. It will signal this detection by switching its LED
from green to red. The LED actually mirrors the state of the REX relay rather than the lock
control transistor.
You need to understand how the unit’s control outputs operate in a detection event. In the rest
condition (green LED on; no detection), the lock control transistor is conducting and the
REX relay is deenergized. When an object is detected, the REX relay energizes immediately.
This is to shunt alarm contacts or send a REX signal to an access control system. Fifty
milliseconds later, the lock control transistor switches off which releases the magnetic lock.
This brief delay is to make sure that the access control system has processed the REX signal so
that it won’t alarm if it is also reading lock status detection such as the Senstat feature. A lock
status signal will change state as soon as the lock is de-powered.
In factory set condition, the lock control transistor will remain off for four seconds after detection
has ceased (keeping the lock released). If, during the four seconds, the object moves again, the
detection condition will be maintained for another four seconds after this “new” detection ceases.
For the magnetic lock to resecure, four seconds must pass with no detection. This trailing
edge timing feature is for egress safety and reliability. Otherwise, it is possible for a person to
approach the door (thereby activating the AL-85851) but then stop moving for a brief moment
at the door. The detector would then reset and if the person then quickly lunged into the door
he could receive a bump as his motion could be quicker than the response of the detection to
this new movement. The four second timing feature virtually eliminates this potential problem.
Another operational safety feature is the fact that if power is cut to the AL-85851, the lock
safely releases so that a person wishing to exit is not trapped.
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