LiftMaster 3-Channel Universal Receiver Models 850LM and 850LMC

Application

The LiftMaster 850LM/850LMC receiver is designed for use as a single or three-channel receiver to control up to three gates or commercial door operators. It can also be used with a 3-button remote control to operate the OPEN, CLOSE, and STOP functions on a commercial door operator. This receiver is not compatible with MyQ® enabled garage door openers or devices.

Each channel supports a specific number of remote controls and keypads:

• Channel 1 (CH1): Supports up to 50 remote controls and 2 keypads.
• Channel 2 (CH2): Supports up to 20 remote controls and 2 keypads.
• Channel 3 (CH3): Supports up to 20 remote controls and 2 keypads.

When a channel reaches its maximum capacity for remote controls, all LEDs will blink 3 times. When a channel reaches its maximum capacity for keypads, all LEDs will blink 4 times. While additional accessories can be programmed, the most recently programmed accessory will replace the first one programmed.

Important Note: The receiver allows programming only one button on a remote control to a single channel at a time. If a remote control button is already programmed to Channel 1 and is then programmed to Channel 3, it will be erased from Channel 1 and will only function on Channel 3.

Safety Warnings

⚠️ WARNING: To prevent possible SERIOUS INJURY or DEATH from electrocution:

• Ensure power is NOT connected BEFORE installing the receiver.

⚠️ WARNING: To prevent possible SERIOUS INJURY or DEATH from a moving gate or garage door:

• ALWAYS keep remote controls out of reach of children. NEVER permit children to operate or play with remote control transmitters.
• Activate the gate or door ONLY when it can be seen clearly, is properly adjusted, and there are no obstructions to door travel.
• ALWAYS keep the gate or garage door in sight until completely closed.
• NEVER permit anyone to cross the path of a moving gate or door.

⚠️ WARNING: To prevent possible SERIOUS INJURY or DEATH, the use of CONSTANT OPERATION on residential openers is PROHIBITED.

When this receiver is used to activate a commercial door opener, a reversing edge MUST be installed on the bottom of the door. Failure to install a reversing edge under these circumstances may result in SERIOUS INJURY or DEATH to persons trapped beneath the door.

Wiring and Connections

Refer to your commercial door operator or gate operator owner manual or wiring diagrams for specific wiring information.

Single Channel Configuration

This configuration connects the receiver to a single operator. The receiver has terminals labeled POWER, N.O. (Normally Open), COM (Common), and N.C. (Normally Closed) for each channel (CH1, CH2, CH3). For a single channel setup, typically CH1 is used. The operator will have corresponding terminals for OPEN, CLOSE, COMMON, and STOP.

Diagram Description: A diagram shows the receiver with terminals CH1, CH2, CH3, and POWER. It illustrates connections from the receiver's CH1 terminals (N.O., COM) to the single operator's OPEN and COMMON terminals.

Three Channel Configuration

This configuration allows control of up to three operators or functions. Each channel (CH1, CH2, CH3) on the receiver can be wired to a separate operator's OPEN, CLOSE, or STOP functions, typically using the N.O. and COM terminals.

Diagram Description: A diagram shows the receiver with terminals for CH1, CH2, CH3, and POWER. It illustrates connections to three separate operators. For Operator 1, CH1 (N.O., COM) connects to OPEN and COMMON. For Operator 2, CH2 (N.O., COM) connects to CLOSE and COMMON. For Operator 3, CH3 (N.O., COM) connects to STOP and COMMON.

Wiring for OPEN, CLOSE, STOP (3-Button Control)

This section details wiring for a 3-button remote control setup, which typically uses three channels to control OPEN, CLOSE, and STOP functions for a single operator.

Diagram Description: A diagram shows the receiver's terminals (POWER, N.O., COM, N.C. for CH1, CH2, CH3). It illustrates connections to a single operator's OPEN, CLOSE, COMMON, and STOP terminals, corresponding to the receiver's channels. A separate diagram shows a 3-button control device with OPEN, CLOSE, and STOP buttons, indicating these are used in conjunction with the receiver's programming.

Installation

The receiver and antenna use standard TV Type F coaxial connectors. The antenna can be connected directly to the receiver or installed remotely using a coaxial cable extension kit (Model 86LM for 15 ft. or 86LMT for 25 ft.).

1. Select a location for the receiver that provides access to the terminals and sufficient space for the antenna. Ensure the antenna does not touch metal surfaces and is not bent or folded.
2. Securely fasten the receiver using the provided hook and loop fasteners or screws (not provided).
3. After installation is complete, connect the power supply. Power can be supplied by an 85LM plug-in transformer, a 95LM wired-in transformer, or directly from the operator (9-30V AC or 9-34V DC; refer to power ratings for specific details).

Note: The receiver can command the operator to close the door or gate via constant pressure. This feature is only available with a wireless control panel (Model 885LM). To enable this feature, press and hold the push bar until the gate or garage door moves to the closed position.

Programming

Program a Single Button Remote Control

1. Press and release the Learn button for the desired channel on the receiver. The corresponding LED will glow steadily for 30 seconds.
2. Within 30 seconds, press and hold the button on the remote control that you wish to program to the receiver.
3. Release the remote control button when the receiver's LED blinks and then turns off. Programming is now complete.

Repeat these steps for each remote control you wish to program.

Program a 3-Button Remote Control (OPEN, CLOSE, STOP)

1. Press and release the CH1 Learn button on the receiver.
2. Within 30 seconds, press the desired OPEN button on the remote control.
3. Press and release the CH2 Learn button on the receiver.
4. Within 30 seconds, press the desired CLOSE button on the remote control.
5. Press and release the CH3 Learn button on the receiver.
6. Within 30 seconds, press the desired STOP button on the remote control.

Note: If a remote control button is not pressed within 30 seconds, the LED next to the selected Learn button will turn off. In this case, repeat the programming sequence.

Erase Memory

1. Press and hold the Learn button for the channel you wish to erase.
2. Release the button when the corresponding LED turns off. The memory for that channel has now been erased.

Specifications

• Contact Rating: 5 Amps, 28 Vac or dc Max.
• Power: 9-30V AC or 9-34V DC, 50mA, 60Hz
• RF Frequency: 310, 315, and 390 MHz

Note: If your operator does not meet these power specifications, you will need a transformer (Model 85LM plug-in or 95LM wired-in).

Compatible Accessories

• Remote Controls: Models 811LM, 813LM, 891LM, 893LM, 890MAX, 893MAX, 895MAX, 892LT, 894LT
• Keypads: Models 877LM, 877MAX
• Antenna Extension Kits: Models 86LM, 86LMT
• Antenna Only: K77-36541

Technical Support

For technical support, please call the toll-free number: 1-800-528-2806.

Compliance Notice

Notice: To comply with FCC and/or Industry Canada (IC) rules, adjustment or modifications of this receiver are prohibited. There are no user-serviceable parts.

This device complies with Part 15 of the FCC rules and IC RSS-210. Operation is subject to the following two conditions: (1) this device may not cause harmful interference, and (2) this device must accept any interference received, including interference that may cause undesired operation.