Genuine LiftMaster K79-13493SJ logic board assembly — the standard control board for the SJ wall-mounted starter (jackshaft) commercial operators: SJ1011, SJ1021, SJ1023, SJ1043 and SJ1053. The SJ is a contactor-style operator with a small logic board rather than a full Logic 5 box, and two fire-door variants of this board exist for the FDCL and FDOA models.
Three SJ boards. K79-13493SJ is the standard board (this page). K79-13493-2 is the FDCL fire-door close board and K79-13493A the FDOA fire-door board (with the K79-13493A-400 chip). Read the number printed on the board and the model on the operator label.
Specifications
| Part number | K79-13493SJ |
|---|---|
| LiftMaster description | Logic Board Assembly — SJ starter operators |
| Fits | SJ1011, SJ1021, SJ1023, SJ1043 (single- and three-phase starters), SJ1053 |
| Variants | K79-13493-2 (FDCL), K79-13493A (FDOA) |
| Condition | Genuine LiftMaster OEM, new |
Which operators use it
| Operator | Parts page |
|---|---|
| SJ1011, SJ1021, SJ1023, SJ1043 wall-mounted starters | SJ starter parts |
| SJ1053 | SJ1053 parts |
Parts often replaced with it
K21-16699 transformer · 25-2020 overload, 20 A 1PH · K20-1100C-2P motor
Is the board actually the problem?
The logic board is the most over-ordered part on a commercial operator. Work down this list before you buy:
| Symptom | Check first |
|---|---|
| Operator dead, no control voltage | Supply, the overload and the K21-16699 transformer before the board |
| Contactor pulls in but the motor does not run | The overload and the motor, not the board |
| Door will not stop at the limit | Limit switches and the limit nuts before the board |
| Board dead after a storm | The board — fit surge protection with it |
After fitting
Set the limit nuts, check the overload setting against the motor nameplate, and re-test the entrapment protection before returning the door to service.
Fit surge protection when you fit the board. Lightning and utility surges are the most common reason a commercial operator board is replaced, and a new board on the same unprotected supply is at the same risk. The MOV kit on the electrical box is the first line; a proper surge arrester on the supply is the second.
Related
SJ starter parts · SJ1053 parts · all LiftMaster commercial door parts
Not sure which board you need? Send a photo of the number printed on your existing board to parts@gatehousesupplies.com or call 866-965-5599. We would rather confirm it than have you fit the wrong board.
