Optical Encoder (RPM Sensor) 39272T.S - Belt/ Chain Drive Models

PDF Instructions for replacing the 39272T.S Optical Encoder 

These instructions are written assuming that you will have ample room around Opener to perform this repair. Some rare instances will require removal of the unit from it’s mounting hardware and repair made on a bench or floor. Refer to your Owners Manual or Installation Poster for proper assembly and carefully read and understand all warnings and cautions pertaining to your unit.

39272T.S 24V DC Opto Replacement For Chain & Belt Operators

WARNING
BE SURE ELECTRICAL POWER HAS BEEN DISCONNECTED FROM THE OPENER PRIOR TO REMOVING THE MOTOR COVER.

WARNING
ANY AND ALL REPAIRS MADE TO THIS UNIT MUST BE PERFORMED WITH THE DOOR DISCONNECTED FROM THE OPENER AND IN THE CLOSED POSITION.

Tools required: Standard slotted and Phillips head screwdrivers, small slotted screwdriver, 5/16” nut driver.

CLOSE THE GARAGE DOOR PRIOR TO REPAIR.

1. Remove power from the operator.

2. Press down on tabs to remove the lens.

3. Remove light bulbs.

4. Note locations and remove BWC (Basic Wall Control) and STB (Safe-T-Beam®) wires. Use a small screwdriver to press in on orange tabs to remove wires. FIG. 1.

5. If equipped, unplug and remove battery backup (BBU) from the back of motor housing. Fig. 2.

6. Using a 5/16” nut driver or common screwdriver, remove the 2 opener cover screws and remove opener cover. FIG-3A

7. Note the locations and disconnect lights, transformer primary, AC power, red & black motor wires, transformer secondary, and encoder harnesses. FIG. 4

8. Using a 1/4” nut driver or common screwdriver, remove 2 control board mounting screws and then remove the control board. FIG. 5.

9. Carefully remove all harnesses from the harness keepers.

10. Remove Opto Assembly cover screws (3-3/16”) leave harness plugged into assembly FIG. 3B.

11. Install replacement Opto Assembly and install cover screws (3).

12. Carefully slide all harnesses back into harness keepers.

13. Reinstall the control board, harnesses, and opener cover in reverse order. Ensure that harnesses are plugged in the correct positions. See harness detail FIG. 6.

14. Reinstall BWC & STB wires, light bulb, and lens.

15. Install BBU assembly onto motor housing if equipped.

16. Reapply power to the operator.

NOTE: Limit settings will require reprogramming. Refer to your owners manual for detailed instructions.

IMPORTANT: Test opener functions. The door MUST reverse on contact with a 1-1/2” high object (or a 2 x 4 board laid flat) at the center of the doorway on the floor. After adjusting either the force or limit of travel, retest door opener. Failure to adjust the opener properly may cause severe injury or death.