General Description
This power supply provides the necessary electronics for
controlling a complete automated door opening system by
coordinating the control of an electrified locking device and
automatic door operator, resulting in a proper sequence of
operation from beginning to end of cycle. The paragraph below
describes how the system operates, and gives the installer an
idea of what can be expected once the system has been
installed and is ready for testing.
To start the automatic opening cycle, a control device, normally
located next to the opening on the entry and exit sides, is
activated. Immediately, the electrified locking device releases
to allow the door to swing freely. After a brief delay (about 1
second), the input to the automatic door operator unit receives
a dry contact signal from the 2904 power supply, and the door
is driven to the open position. The signal to the operator unit
resets within approximately 3 - 5 seconds from the time it had
been received. From this point, the “Door Hold-Open” time
delay built into the automatic door operator unit continues to
hold the door in the open position for as long as the delay had
been initially set, or programmed for. Once this delay times out,
the door will then freely close shut and become locked via the
electrified locking device. (The locking device switches back
from the unlocked state to the locked state at the same time the
signal to the automatic door operator is aborted.) The cycle is
completed, and the system is now ready for the next activation
occurrence.
Activation Switches
Marked as OAS for “Outside Activation Switch”, and IAS for
“Inside Activation Switch” at terminal block TB1, these inputs
normally require a normally open, momentary switch for
activating the automated door opening system. The most
commonly used of these types are wall mounted push-button
switches with large diameter actuators, such as used for
handicap access. Card readers and keypads can be used for
authorized access. They utilize the normally open, dry contact
output of a relay for activating the system. For best results
when using these devices, have their built-in time delay set for
one second, simulating the approximate length of time for a
contact closure when depressing a push-button switch. By
doing this, there are no extended delays to get confused with
when coordinating the door hold open time adjustment on the
automatic door operator unit with the 3 - 5 second delay
generated by the output signal from the 2904 power supply to
the operator input.
Maintain Switch Option
By wiring a maintain switch in parallel with a momentary switch
across the OAS or IAS input terminals, the signal to the
automatic door operator can be extended (while the switch
contacts remain closed) for an indefinite period of time, and will
hold the door in a maintained open position. This may prove
useful in places where extra time is needed to move carts or
other equipment through the door. When the maintain switch
contacts are opened, the door will then close after the “Door
Hold-Open” delay programmed into the automatic door
operator unit times out.
One-Shot Activation Option
The 2904 can be programmed to allow the automated door
opening sequence to go through its complete open/close cycle
in spite of a constant maintained contact closure held across the
OAS or IAS input terminals. This option may be desirable in
overcoming any deliberate attempts at holding the activation
switch in the closed position which would cause the door to
remain in a maintained open position, contrary to its normal
cycle. To program in this option, place the slide switch marked
“1” on the onboard dip switch bank to the position opposite the
“ON” position, as shown below:
The dot shown above marks the position of the switch.
Note: When using the one-shot activation option, the
following point must be observed: With the activation switch
contacts in the maintained closed position, and after completion
of a full open/close cycle, before the next activation can occur,
the activation switch contacts must be held open for 4 seconds
(for resetting the delay circuit) before closing to reactivate the
cycle.
Electrified Locking Devices
The 2904 is provided with an output for wiring to a fail safe type
locking device (marked as FSF at terminal block TB1) and
another output for a fail secure type locking device (marked as
FSC). All locking devices must be rated 24VDC.
The
maximum allowable current draw for either output is 1
amp. (If a pair of doors is used in the application, and each leaf
contains an electrified locking device, the maximum current
draw for each device must be 0.5 amp.)
The most common type of fail safe locking device used on this
kind of system is the electromagnetic lock. A complete riser
diagram and point-to-point wiring diagram depicting an
application utilizing this type of locking device can be found at
the end of this manual, shown as figures 1a and 1b respectively.
A latching type of fail safe electrified locking device can be used
providing that it is designed to have its latch retracted in less
than 1 second upon removal of power when the cycle has been
activated, and providing the solenoid or motor used in the
device does not draw more than 1 amp at 24VDC.
2904 Power Supply
Installation Instructions
I-EA00041
REV 2
Page 2 of 6
INSTALLATION INSTRUCTIONS (cont)
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