Electrify compatible BEST Precision 2000 and 5000 Series exit devices with the ACSI 1550K-MDP Motorized Latch Retraction and Dogging Kit.

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

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

Key Features

• Genuine ACSI – Architectural Control Systems

• Model 1550K-MDP

• Series 1550K-MD

• Designed specifically for:

  • BEST Precision 2000 Series

  • BEST Precision 5000 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

• Field-installable kit

• Factory installation available

• Interfaces with access-control systems

• Compatible with automatic door operators

• UL listed for compatible panic exit hardware

• UL listed for compatible fire exit hardware

• Exit device sold separately

Compatible Exit Devices

The MDP suffix identifies this ACSI kit specifically for:

BEST Precision

• 2000 Series

• 5000 Series

Important

The ACSI 1550K-MD family uses different motor kits for different exit-device manufacturers.

The 1550K-MDP should only be used with compatible BEST Precision 2000 and 5000 Series exit devices.

Motorized Latch Retraction

When the kit receives 24VDC power, 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-MDP provides:

Electric Latch Retraction + Electric Dogging

When energized:

1. The exit-device latch retracts

2. The touchbar depresses

3. The touchbar remains in the dogged position

4. The opening operates in a free-passage condition

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

Electrical Requirements

Operating Voltage: 24VDC ±10%

Maximum Inrush Current: 1 Amp

Maximum Holding Current: 400mA

Leads: Non-Polarized

A properly sized:

Filtered and Regulated 24VDC Power Supply

is required.

ACSI recommends its compatible Series 1400 power supplies for electric exit-device applications.

Continuous-Duty Operation

The 1550K-MDP 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 free passage

• Automatic door entrances

• High-traffic commercial openings

• Institutional facilities

Quiet Motorized Operation

The motor-drive system provides quieter operation than many traditional solenoid latch-retraction systems.

This is particularly useful in:

• Hospitals

• Healthcare facilities

• Schools

• Universities

• Libraries

• Office buildings

• Hotels

• Institutional facilities

Automatic Retry

The 1550K-MDP includes an:

Automatic Retry Function

If the device cannot successfully complete the latch-retraction cycle because of temporary binding or resistance, the control can attempt the retraction cycle again.

Diagnostic LEDs

On-board diagnostic LEDs assist technicians with:

• Installation

• Setup

• Testing

• Troubleshooting

• Operational verification

The diagnostic system can help identify conditions involving:

• Power

• Sensor position

• Failed retraction

• Device binding

• Low voltage

• Motor or control faults

Non-Polarized Leads

The kit uses:

Non-Polarized Wiring Leads

to simplify field installation.

Device Length Compatibility

ACSI specifies maximum allowable cutoff from standard device lengths.

Standard 36" Exit Device

Maximum Allowable Cutoff: 1/2"

Standard 48" Exit Device

Maximum Allowable Cutoff: 8-1/2"

Important

Verify the existing device length before ordering.

A Precision device that has already been shortened beyond these limits may not provide enough internal space for the motor-drive assembly.

Recommended Wire Size

For a two-conductor 24VDC circuit, ACSI provides the following general wire-run 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

Voltage drop and other system loads should be considered when designing the installation.

Manual Dogging Removal

If manual dogging components are present in the exit device, the ACSI installation procedure calls for removal of those components during installation.

The motorized assembly then provides the electric dogging function.

Field-Installable Kit

The K designation identifies the product as a:

Field-Installable Kit

Installation involves separating the device channel from the touchbar assembly and installing the ACSI motor-drive components.

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

Factory Installation

The motor-drive modification can also be factory installed when ordering or supplying a compatible Precision exit device through ACSI.

Access-Control Integration

The 1550K-MDP can interface with compatible:

• Access-control panels

• Card readers

• Keypads

• Request-to-enter systems

• Building management systems

• Timers

• Remote switches

• Control relays

Automatic Door Operator Applications

The 1550K-MDP works well with automatic swing-door systems when properly sequenced.

A typical sequence is:

1. Access is authorized

2. 1550K-MDP receives power

3. Exit-device latch retracts

4. Touchbar moves into the dogged position

5. Automatic operator activates

6. Door opens

7. Door completes the operating cycle

8. Exit device returns to secure operation when power is removed

Proper sequencing is important so the operator does not attempt 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 a fire-rated opening, the entire assembly must maintain the required listing, including:

• Door

• Frame

• Exit device

• Electrification kit

• Power supply

• Wiring

• Control system

Always follow applicable life-safety and fire-door requirements.

Common Applications

Ideal for:

• Access-controlled doors

• Automatic door entrances

• Schools

• Universities

• Hospitals

• Healthcare facilities

• Government buildings

• Office buildings

• Retail facilities

• Airports

• Institutional facilities

• Scheduled unlock systems

• Remote-release applications

• High-traffic commercial entrances

Product Specifications

Brand: ACSI
Manufacturer: Architectural Control Systems, Inc.
Series: 1550K-MD
Model: 1550K-MDP
Product Type: Motorized Latch Retraction / Dogging Kit
Compatible Manufacturer: BEST Precision
Compatible Series: 2000 / 5000
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: 1/2"
48" Device Maximum Cutoff: 8-1/2"
Panic Hardware Listed: Yes
Fire Exit Hardware Listed: Yes
Exit Device Included: No

Compatible Exit Device Series

BEST Precision

• 2000 Series

• 5000 Series

What's Included

Typical kit includes:

• ACSI motorized latch-retraction assembly

• Precision-specific motor bracket

• Connecting link

• Ratchet clip

• Wiring leads

• Mounting hardware

• Technical assistance labels

Exact kit contents may vary with production revisions.

Not Included

• BEST Precision 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 is a compatible BEST Precision 2000 or 5000 Series

• Exact exit-device configuration

• Device length

• Amount the device has been shortened

• Existing dogging configuration

• Rim, mortise, SVR, or CVR application

• 24VDC power-supply capacity

• Wire distance and gauge

• Automatic operator requirements

• Panic or fire-exit application

Important

1550K-MDP = BEST Precision 2000 / 5000 Series

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