Electrify compatible DORMA 9000 Series exit devices with the ACSI 1550K-MDD Motorized Latch Retraction and Dogging Kit.

The 1550K-MDD provides quiet, continuous-duty 24VDC motorized latch retraction, allowing a compatible exit device to be remotely unlocked through an access-control system, automatic door operator, time schedule, or remote release.

When energized, the system simultaneously retracts the latch and depresses the pushpad into the dogged position for free passage.

Key Features

• Genuine ACSI – Architectural Control Systems

• Model 1550K-MDD

• Series 1550K-MD

• Specifically designed for DORMA 9000 Series exit devices

• Motorized electric latch retraction

• Simultaneous latch retraction and dogging

• 24VDC operation

• 1A inrush current

• 400mA holding current

• Continuous-duty rated

• Quiet motorized operation

• Low power consumption

• Non-polarized wiring leads

• On-board diagnostic LEDs

• Automatic retry feature

• Field-installable kit

• Factory installation available

• UL listed for compatible panic exit hardware

• UL listed for compatible fire exit hardware

• Interfaces with access-control and life-safety systems

• Exit device sold separately

DORMA 9000 Series Compatibility

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

DORMA 9000 Series Exit Devices

Important

ACSI manufactures multiple versions of the 1550K-MD system for different exit-device manufacturers.

The suffix is critical.

1550K-MDD = DORMA 9000 Series

Do not substitute another 1550K-MD suffix without confirming exit-device compatibility.

Motorized Latch Retraction

The 1550K-MDD provides:

Electric Motor Latch Retraction

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

This allows the door to be electronically unlocked without requiring someone to manually depress the pushpad.

Simultaneous Electric Dogging

When energized, the system also depresses and maintains the pushpad in the retracted position.

This provides:

Latch Retraction + Electric Dogging

The opening can then function in a free-passage condition for as long as the system remains energized.

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

24VDC Electrical Requirements

The 1550K-MDD operates at:

24VDC

Electrical Load

Inrush: 1 Amp
Holding: 400mA

The lower holding current allows the motorized system to remain energized for extended unlock periods when properly powered.

Continuous-Duty Operation

The 1550K-MDD is:

Continuous-Duty Rated

This makes it suitable for applications requiring the latch to remain electrically retracted for extended periods, such as:

• Business-hour unlocking

• Scheduled access periods

• High-traffic entrances

• Automatic door operation

Quiet Motorized Operation

The motor-drive system is designed for quieter operation than many traditional high-inrush solenoid latch-retraction systems.

This makes it useful in:

• Hospitals

• Healthcare facilities

• Schools

• Libraries

• Offices

• Hotels

• Institutional buildings

Automatic Retry

The 1550K-MDD includes:

Automatic Retry

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

Diagnostic LEDs

On-board LEDs provide diagnostic information for:

• Installation

• Setup

• Testing

• Troubleshooting

• Service

Non-Polarized Leads

The kit uses:

Non-Polarized Leads

to simplify field wiring.

Access-Control Integration

The 1550K-MDD can be integrated with compatible:

• Card readers

• Keypads

• Access-control panels

• Remote release switches

• Timers

• Building management systems

• Door-control relays

• Automatic door operators

Automatic Door Operator Applications

Motorized latch retraction is particularly useful when a DORMA 9000 exit device is installed on a door with an automatic operator.

A typical sequence may be:

1. Access credential is accepted

2. 1550K-MDD retracts the exit-device latch

3. Exit device reaches the dogged position

4. Automatic operator receives activation signal

5. Door opens

6. Door closes after the cycle

7. Latch returns to the secure position

Proper control sequencing is required.

Panic & Fire Exit Hardware

ACSI lists its 1550K-MD motorized latch-retraction system for use with compatible:

• Panic exit hardware

• Fire exit hardware

Fire-Rated Openings

When used on a fire-rated opening, the complete:

• Door

• Frame

• Exit device

• Electrification kit

• Power supply

• Wiring

• Control system

must maintain the required listing and life-safety operation.

Compatible Exit Device Types

The ACSI 1550K-MD platform supports compatible:

• Rim exit devices

• Mortise exit devices

• Surface vertical rod devices

• Concealed vertical rod devices

Exact availability depends on the specific DORMA 9000 Series configuration.

Field-Installable Kit

The K designation identifies the 1550K-MDD as a kit configuration suitable for field installation on compatible exit devices.

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

ACSI Power Supplies

ACSI recommends compatible:

Series 1400 Power Supplies

for motorized latch-retraction applications.

The power supply must be sized according to:

• Number of exit devices

• Wire length

• Wire gauge

• Control sequence

• Simultaneous device operation

• Additional system loads

Exit Device Not Included

Important

The 1550K-MDD is an:

Electrification Kit Only

The complete DORMA 9000 Series exit device is sold separately.

Common Applications

Ideal for:

• Automatic door systems

• Access-controlled entrances

• Schools

• Universities

• Hospitals

• Healthcare facilities

• Government buildings

• Airports

• Office buildings

• Retail facilities

• Institutional facilities

• Remote unlocking applications

• Scheduled unlock applications

Product Specifications

Brand: ACSI
Manufacturer: Architectural Control Systems, Inc.
Series: 1550K-MD
Model: 1550K-MDD
Product Type: Motorized Latch Retraction / Dogging Kit
Compatible Exit Device: DORMA 9000 Series
Voltage: 24VDC
Inrush Current: 1A
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
Panic Hardware Listed: Yes
Fire Exit Hardware Listed: Yes
Exit Device Included: No

What's Included

Typical kit includes:

• Motorized latch-retraction assembly

• DORMA 9000-specific mounting components

• Wiring leads

• Installation hardware

• Identification labels

Exact kit contents may vary with production revisions and exit-device configuration.

Not Included

• DORMA 9000 Series exit device

• 24VDC power supply

• Power transfer

• Access-control reader

• Automatic door operator

• Control relay

• Field wiring

• Door

• Frame

• Installation labor

Important Ordering Information

Before ordering, verify:

• Exit device is a compatible DORMA 9000 Series

• Rim, mortise, SVR, or CVR configuration

• Device length

• Existing exit-device configuration

• 24VDC power supply capacity

• Wire gauge and distance

• Access-control sequence

• Fire-rated or panic-only opening

• Automatic operator requirements

Important

1550K-MDD = DORMA 9000 Series

The MDD suffix is manufacturer-specific and should not be treated as interchangeable with the MDC, MDT, MDV, or other ACSI 1550K-MD kits.