The LiftMaster 24-51233 brake solenoid relay is a service relay used in the industrial brake circuit on select LiftMaster SL3000 commercial slide gate operators. In this type of operator, the brake assembly helps hold the gate when the motor is not driving and releases when the operator is commanded to run. A weak, failed, or incorrect relay can cause a brake that does not release, intermittent movement, humming, nuisance stops, or a gate that feels mechanically locked even though the control board is calling for movement. This is not a general-purpose accessory relay; it belongs in a specific brake control circuit and should be selected by part number, operator model, and wiring diagram. On high-use commercial slide gates, replacing the relay without checking the brake solenoid, wiring, line voltage, and limit/brake timing can leave the original problem unresolved.
| Manufacturer | LiftMaster / Chamberlain Group |
|---|---|
| Product Type | Brake solenoid relay |
| Part Number | 24-51233 |
| Application | Industrial brake solenoid control circuit |
| Compatible Operator Type | Select commercial slide gate operators |
| Common Model Reference | SL3000ULE / SL3000UL family |
| Horsepower Reference | Commonly listed for 2 HP brake relay applications |
| Notes | Match by parts diagram, relay markings, and wiring layout |
If the brake does not release, test the relay as part of the full brake circuit instead of assuming the relay is the only failed item. Check the brake solenoid, wiring terminals, voltage supply, and any heat damage around the brake-control components.
Electrical components should be installed and tested by a qualified gate technician. Disconnect power before service and do not bypass safety devices, overload protection, alarms, or manufacturer-required entrapment protection devices.
It controls the brake solenoid circuit on select SL3000 commercial slide gate operators so the brake can release during movement and hold when the operator stops.
No. It is mainly associated with SL3000UL and SL3000ULE brake-control applications, but the installed model and parts diagram should be checked before ordering.
Yes. If the brake solenoid does not release, the motor may try to run while the brake is still holding. Other brake, wiring, voltage, or control issues can cause similar symptoms.
No. The relay controls the brake solenoid circuit. The brake solenoid assembly is a separate part and should be diagnosed separately.
This part is inside a commercial gate operator electrical system. A qualified gate technician should diagnose and replace it safely.