Electrify compatible Falcon 1690/1790 and First Choice 3600/3700 Series exit devices with the ACSI 1550K-MDO Motorized Latch Retraction and Dogging Kit.

Designed specifically for these exit-device families, the 1550K-MDO provides quiet 24VDC motorized latch retraction, allowing the opening to be remotely unlocked through an access-control system, automatic door operator, time schedule, or remote release.

When energized, the motor retracts the exit-device latch while simultaneously depressing the touchbar into the dogged position for controlled free passage.

Key Features

• Genuine ACSI – Architectural Control Systems

• Model 1550K-MDO

• Series 1550K-MD

• Specifically designed for:

  • Falcon 1690 Series

  • Falcon 1790 Series

  • First Choice 3600 Series

  • First Choice 3700 Series

• Motorized electric latch retraction

• Simultaneous latch retraction and electric dogging

• 24VDC ±10%

• 1A maximum inrush current

• 400mA maximum holding current

• Continuous-duty rated

• Quiet motor-driven operation

• Low power consumption

• Non-polarized wiring leads

• On-board diagnostic LEDs

• Automatic retry feature

• Field-installable kit

• Factory installation available

• Interfaces with access-control systems

• Compatible with automatic door operator applications

• UL listed for compatible panic exit hardware

• UL listed for compatible fire exit hardware

• Exit device sold separately

Compatible Exit Devices

The MDO suffix identifies the ACSI motorized latch-retraction kit designed specifically for:

Falcon

• 1690 Series

• 1790 Series

First Choice

• 3600 Series

• 3700 Series

Important

The ACSI 1550K-MD family uses different suffixes for different exit-device manufacturers and series.

The 1550K-MDO should not be substituted for another 1550K-MD kit without confirming compatibility.

Motorized Latch Retraction

When 24VDC power is applied, the internal motor retracts the exit-device latch.

This allows the opening to be electronically unlocked without requiring someone to manually depress the touchbar.

Common control methods include:

• Card readers

• Keypads

• Access-control panels

• Time schedules

• Remote release switches

• Building automation systems

• Automatic door operators

Simultaneous Electric Dogging

The 1550K-MDO provides:

Latch Retraction + Electric Dogging

When energized:

1. The exit-device latch retracts

2. The touchbar depresses

3. The bar remains in the dogged position

4. The opening operates in free-passage mode

When power is removed, the device returns to its normal mechanical secure condition.

Electrical Requirements

Operating Voltage: 24VDC ±10%

Maximum Inrush Current: 1 Amp

Maximum Holding Current: 400mA

Lead Type: Non-Polarized

The kit requires a:

Filtered and Regulated 24VDC Power Supply

Proper power-supply sizing is important for reliable operation.

Continuous-Duty Operation

The 1550K-MDO is:

Continuous-Duty Rated

This allows the exit device to remain electrically retracted for extended periods when connected to a properly sized power supply.

Typical applications include:

• Business-hours unlocking

• Scheduled access periods

• High-traffic commercial entrances

• Automatic door systems

• Institutional facilities

Quiet Motorized Operation

The 1550K-MDO uses a motor-driven mechanism rather than a traditional high-inrush solenoid.

This provides quieter operation for applications such as:

• Schools

• Universities

• Healthcare facilities

• Hospitals

• Libraries

• Offices

• Hotels

• Institutional buildings

Automatic Retry

The motor-drive electronics incorporate:

Automatic Retry

If the device cannot successfully complete the latch-retraction cycle because of temporary resistance, binding, or misalignment, the system can automatically attempt another cycle.

This helps improve reliability on commercial openings where door hardware may experience normal wear or alignment changes.

On-Board Diagnostic LEDs

Integrated LEDs assist installers and service technicians with:

• Setup

• Testing

• Troubleshooting

• Operational verification

The diagnostic system can help identify issues involving:

• Power

• Retraction

• Pushbar position

• Binding

• Voltage

• Motor operation

Non-Polarized Leads

The 1550K-MDO uses:

Non-Polarized Wiring Leads

which simplifies 24VDC field wiring.

Device Length Compatibility

ACSI specifies a maximum allowable cutoff from the standard exit-device length.

Standard 36" Device

Maximum Cutoff: 2"

Standard 48" Device

Maximum Cutoff: 2"

Important

Verify the actual device length and any previous field modification before ordering the retrofit kit.

An exit device that has been shortened beyond the permitted amount may not have sufficient internal space for the motor assembly.

Wire Run Recommendations

For a two-conductor 24VDC run, ACSI provides the following general wire-sizing guidance:

• 70 ft – 22 AWG

• 110 ft – 20 AWG

• 180 ft – 18 AWG

• 280 ft – 16 AWG

• 450 ft – 14 AWG

• 720 ft – 12 AWG

Actual system design should account for voltage drop and any additional connected loads.

Manual Dogging Removal

During installation, the existing:

Manual Dogging Assembly

is removed from the device.

The motorized kit then provides the electric dogging function.

This means the opening is controlled electrically rather than through the original manual dogging mechanism.

Field-Installable Kit

The K designation identifies the 1550K-MDO as a:

Field-Installable Motor Drive Kit

The retrofit requires access to the exit-device touchbar and internal channel.

Professional installation by a qualified commercial-door or access-control technician is recommended.

Factory Installation

ACSI can also provide the motor-drive modification as a factory-installed configuration.

This may be preferable when:

• Ordering new exit devices

• Building a complete electrified opening

• Minimizing field labor

• Maintaining consistent factory assembly

Access-Control Integration

The 1550K-MDO can be controlled by compatible:

• Access-control panels

• Card readers

• Keypads

• Request-to-enter systems

• Building management systems

• Timers

• Remote switches

• Relays

A properly rated relay and power supply may be required depending on the system design.

Automatic Door Operator Applications

The 1550K-MDO is particularly useful on doors equipped with an automatic operator.

A typical operating sequence may be:

1. User presents an authorized credential

2. Access-control system energizes the 1550K-MDO

3. Exit-device latch retracts

4. Touchbar moves into the dogged position

5. Automatic operator receives activation signal

6. Door opens without fighting the latch

7. Door completes its operating cycle

8. Latch returns to secure operation when power is removed

Proper sequencing is required to prevent the automatic operator from attempting to open the door before the latch is fully retracted.

Panic & Fire Exit Hardware

The ACSI 1550K-MD platform is UL listed for compatible:

• Panic exit hardware

• Fire exit hardware

Important

For fire-rated openings, the complete assembly must maintain its required listing, including:

• Door

• Frame

• Exit device

• Electrification kit

• Power supply

• Wiring

• Control system

Always follow the exit-device manufacturer's requirements and applicable life-safety codes.

Common Applications

Ideal for:

• Access-controlled doors

• Automatic door entrances

• Schools

• Universities

• Hospitals

• Healthcare facilities

• Government buildings

• Airports

• Retail facilities

• Office buildings

• Institutional facilities

• Scheduled unlock applications

• Remote release applications

• High-traffic commercial entrances

Product Specifications

Brand: ACSI
Manufacturer: Architectural Control Systems, Inc.
Series: 1550K-MD
Model: 1550K-MDO
Product Type: Motorized Latch Retraction / Dogging Kit
Compatible Manufacturer: Falcon / First Choice
Compatible Falcon Series: 1690 / 1790
Compatible First Choice Series: 3600 / 3700
Voltage: 24VDC ±10%
Maximum Inrush Current: 1A
Maximum Holding Current: 400mA
Duty Rating: Continuous
Operation: Electric Latch Retraction and Dogging
Motorized: Yes
Automatic Retry: Yes
Diagnostic LEDs: Yes
Wiring Leads: Non-Polarized
Field Installable: Yes
Factory Installable: Yes
36" Device Maximum Cutoff: 2"
48" Device Maximum Cutoff: 2"
Panic Hardware Listed: Yes
Fire Exit Hardware Listed: Yes
Exit Device Included: No

Compatible Exit Device Series

Falcon

• 1690 Series

• 1790 Series

First Choice

• 3600 Series

• 3700 Series

What's Included

Typical 1550K-MDO kit includes:

• Motorized latch-retraction assembly

• Device-specific motor bracket

• Connecting hardware

• Wiring leads

• Mounting hardware

• Installation components

Exact kit contents may vary with manufacturing revisions.

Not Included

• Falcon or First Choice exit device

• 24VDC power supply

• Power transfer

• Access-control reader

• Keypad

• Automatic door operator

• Control relay

• Field wiring

• Door

• Frame

• Installation labor

Important Ordering Information

Before ordering, verify:

• Exit-device manufacturer

• Exact device series

• Falcon 1690 or 1790

• First Choice 3600 or 3700

• Device length

• Amount the device has already been cut down

• Exit-device configuration

• Existing dogging arrangement

• 24VDC power-supply capacity

• Wire distance and gauge

• Automatic operator requirements

• Panic or fire-exit application

Important

1550K-MDO = Falcon 1690 / 1790 and First Choice 3600 / 3700

Do not substitute the 1550K-MDF, which is the separate ACSI kit for Falcon 24 and 25 Series devices.