Liftmaster 25-4008, RELAY, OVERLOAD, 5.5-8A
The LiftMaster 25-4008 overload relay is a motor-protection device rated for the 5.5-8 amp range. In a commercial gate operator, the overload relay is part of the motor control circuit and is intended to trip when the motor draws more current than the equipment is designed to handle. That makes the amp range very important. If the installed gate is dragging, the chain is tight, the gearbox is failing, or the motor is undersized for the load, replacing the overload may not fix the real problem. This part should be used when the parts diagram calls for 25-4008 or a matching 5.5-8A overload reference. It is not interchangeable with 6A, 10A, or other overload ranges just because the body style looks similar.
Compatible With
- For use with various LiftMaster commercial gate operators that specify a 5.5-8A overload relay.
- Commonly associated with select LiftMaster and OSCO industrial gate operator motor-control assemblies.
- May be used on select 1/2 HP and 3/4 HP commercial operator configurations when the original overload range matches 5.5-8A.
- Related replacement references include K25-4008-D and 25-4008-K in some supplier listings; verify the exact range and terminal layout.
- Verify by operator model, motor nameplate, wiring diagram, and original overload markings before ordering.
Features & Specifications
| Manufacturer | LiftMaster / Chamberlain Group |
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| Product Type | Overload relay |
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| Part Number | 25-4008 |
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| Amp Range | 5.5-8A |
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| Application | Motor overload protection |
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| Compatible Operator Type | Select commercial gate operators |
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| Related Operator Families | Various LiftMaster and OSCO industrial gate operators when specified |
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| Notes | Amp range must match the motor and operator wiring diagram |
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Also Known As / Related Part Numbers
- 25-4008
- LM-25-4008
- LiftMaster 25-4008
- 25-4008-K
- K25-4008-D
- Overload 5.5-8.0 Amp
- Overload relay 5.5-8A
- LiftMaster overload relay 5.5-8A
Technician Note
Repeated overload trips usually point to a load problem, voltage problem, or failing motor. Check gate travel by hand, chain tension, gearbox drag, voltage under load, and motor nameplate before replacing the overload relay.
Before Ordering
- Confirm the old overload is marked 5.5-8A or the diagram calls for 25-4008.
- Verify motor horsepower, voltage, and phase.
- Compare terminal layout and mounting style.
- Inspect the gate for binding before returning the operator to service.
- Do not substitute a different overload range without manufacturer support.
Important Ordering Warnings
- Wrong amp range can damage the motor or cause nuisance shutdowns.
- A tripping overload is a symptom, not always the failed part.
- Do not bypass the overload relay.
- High-voltage motor-control work should be handled by a qualified technician.
Professional Advisory
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.
Product Questions & Answers
Why is the amp range important on 25-4008?
The overload must match the motor current range. A different range can trip too early or fail to protect the motor during an overload condition.
Can I replace a 6A or 10A overload with this 5.5-8A relay?
No. Match the original overload rating, motor nameplate, and parts diagram. Different amp ranges are not automatic substitutes.
What causes an overload relay to trip repeatedly?
Common causes include a binding gate, worn rollers or hinges, tight chain, failing gearbox, incorrect motor load, low voltage, or a motor problem.
Is this used on residential garage door openers?
This part is mainly listed for select commercial gate operator motor-control applications, not standard residential garage door openers.
Should the overload be reset or replaced?
If it trips once, the gate should be inspected. If it is damaged, overheated, out of range, or repeatedly trips after mechanical issues are corrected, replacement may be needed.
