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Square D LH36300 Molded Case Circuit Breaker
- 300A
- 3 Pole
- I-Line
Square D
LH36300
Molded Case Circuit Breaker
Brand
Square D
SKU
LH36300
Quantity
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Square D LH36300 - 300A 3 Pole Molded Case Circuit Breaker
New
Quantity
Quantity
Square D LH36300 - 300A 3 Pole Molded Case Circuit Breaker
New
Quantity
| Brand | Square D |
|---|---|
| Part Number | LH36300 |
| Series | LH |
| Amperage | 300A |
| Poles | 3 |
| Mounting Style | I-Line |
| Voltage | 240VAC, 480VAC, 600VAC, 250VDC |
| Phase | 3 |
| AIC Rating | 65kA @ 240VAC, 35kA @ 480VAC, 25kA @ 600VAC, 50kA @ 250VDC |
| Frame Type | LH |
|---|---|
| Terminal Type | Lugs |
| For Use With | Square D I-Line Panelboards and Switchboards |
| Wire Gauge | (1) 1 AWG-600 kcmil (Al/Cu) or (2) 1 AWG-250 kcmil (Al/Cu) |
| Max Wire | 600 kcmil |
| Min Wire | 1 AWG |
| Trip Technology | Thermal Magnetic |
|---|---|
| Trip Function Code | LI |
| Trip Function | Long-Time, Instantaneous |
| Trip Adjustability | Fixed Thermal, Adjustable Magnetic |
| Available Options | Shunt Trip, Auxiliary Switch, Alarm Switch, Undervoltage Release |
|---|---|
| Accessories | Lugs (AL400LA) |
| Standards | CSA C22.2 No. 5, IEC 60947-2, NEMA AB 1, UL 489 |
| Approval | CSA, HACR, IEC, UL |
| Temp Rating | 40C |
| Construction Features | HACR Rated, High Interrupting Capacity, Push-To-Trip |
Quantity
Square D LH36300 - 300A 3 Pole Molded Case Circuit Breaker
Re-Certified
Quantity
| Brand | Square D |
|---|---|
| Part Number | LH36300-R |
| Series | LH |
| Amperage | 300A |
| Poles | 3 |
| Mounting Style | I-Line |
| Voltage | 240VAC, 480VAC, 600VAC, 250VDC |
| Phase | 3 |
| AIC Rating | 65kA @ 240VAC, 35kA @ 480VAC, 25kA @ 600VAC, 50kA @ 250VDC |
| Frame Type | LH |
|---|---|
| Terminal Type | Lugs |
| For Use With | Square D I-Line Panelboards and Switchboards |
| Wire Gauge | (1) 1 AWG-600 kcmil (Al/Cu) or (2) 1 AWG-250 kcmil (Al/Cu) |
| Max Wire | 600 kcmil |
| Min Wire | 1 AWG |
| Trip Technology | Thermal Magnetic |
|---|---|
| Trip Function Code | LI |
| Trip Function | Long-Time, Instantaneous |
| Trip Adjustability | Fixed Thermal, Adjustable Magnetic |
| Available Options | Shunt Trip, Auxiliary Switch, Alarm Switch, Undervoltage Release |
|---|---|
| Accessories | Lugs (AL400LA) |
| Standards | CSA C22.2 No. 5, IEC 60947-2, NEMA AB 1, UL 489 |
| Approval | CSA, HACR, IEC, UL |
| Temp Rating | 40C |
| Construction Features | HACR Rated, High Interrupting Capacity, Push-To-Trip |
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Description
Operating at 300 amps, this 3-pole molded case circuit breaker from the Square D L-Frame series delivers dependable thermal-magnetic protection. It features long-time and instantaneous (LI) trip functions to secure commercial and industrial electrical systems. This unit mounts into Square D I-Line panelboards and switchboards using a plug-on connection. As a legacy component, it is officially replaced by the LGA36300U31X, which upgrades the system to electronic trip technology.Specifications
| Brand | Square D |
|---|---|
| Part Number | LH36300 |
| Series | LH |
| Amperage | 300A |
| Poles | 3 |
| Mounting Style | I-Line |
| Voltage | 240VAC, 480VAC, 600VAC, 250VDC |
| Phase | 3 |
| AIC Rating | 65kA @ 240VAC, 35kA @ 480VAC, 25kA @ 600VAC, 50kA @ 250VDC |
| Frame Type | LH |
|---|---|
| Terminal Type | Lugs |
| For Use With | Square D I-Line Panelboards and Switchboards |
| Wire Gauge | (1) 1 AWG-600 kcmil (Al/Cu) or (2) 1 AWG-250 kcmil (Al/Cu) |
| Max Wire | 600 kcmil |
| Min Wire | 1 AWG |
| Trip Technology | Thermal Magnetic |
|---|---|
| Trip Function Code | LI |
| Trip Function | Long-Time, Instantaneous |
| Trip Adjustability | Fixed Thermal, Adjustable Magnetic |
| Available Options | Shunt Trip, Auxiliary Switch, Alarm Switch, Undervoltage Release |
|---|---|
| Accessories | Lugs (AL400LA) |
| Standards | CSA C22.2 No. 5, IEC 60947-2, NEMA AB 1, UL 489 |
| Approval | CSA, HACR, IEC, UL |
| Temp Rating | 40C |
| Construction Features | HACR Rated, High Interrupting Capacity, Push-To-Trip |
Product FAQs
8 answersWhat panels will accept the LH36300 circuit breaker?
This breaker is designed specifically for use in Square D I-Line panelboards and switchboards. It will not fit in standard unit-mount or load center panels.
What is the adjustable magnetic trip range for the LH36300?
The magnetic trip is adjustable from a low setting of 1500A to a high setting of 3000A. The thermal protection remains fixed at a continuous 300A.
How does the LH36300 differ from the LA36300?
Both models share the exact same L-frame footprint and 300A rating, but the LH36300 features a High Interrupting Capacity. The LH provides 35kAIC at 480VAC, offering greater short-circuit protection than the standard LA frame.
What is the current Square D replacement for this legacy breaker?
The LH36300 is officially replaced by the modern PowerPact L-Frame series. The direct crossover is catalog number LGA36300U31X, which upgrades the system to electronic trip technology while maintaining I-Line compatibility.
What is the acceptable wire range for the load side lugs?
The factory AL400LA lugs accept either a single 1 AWG to 600 kcmil conductor or two 1 AWG to 250 kcmil conductors per phase. They are rated for both aluminum and copper wire.
How does the line side connection work on this I-Line breaker?
The line side uses plug-on jaws that clamp directly onto the panel bus bars. A mounting bracket with a captive screw is then tightened to secure the breaker firmly to the panel backpan.
How can I verify the mechanical operation of the breaker?
The breaker features a push-to-trip button on the front face. Pressing this button manually trips the mechanism to ensure the mechanical linkages are functioning safely and properly.
Can this molded case circuit breaker be used in DC systems?
Yes, it is rated for up to 250VDC applications and provides a maximum interrupting capacity of 50kAIC at that voltage.
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Reviews
Review summary
Customers rate this product 5.0 out of 5 based on 2 reviews.
Total 5 star reviews: 2 Total 4 star reviews: 0 Total 3 star reviews: 0 Total 2 star reviews: 0 Total 1 star reviews: 0
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Rating
2 reviews
- MLMatthew L.Verified BuyerReviewingSquare D LH36400 - 400A 3 Pole Molded Case Circuit BreakerI recommend this productRated 5 out of 5 stars7/21/26Super Breakers Does It Again!
New, in excellent condition, cheaper and faster than the competition
- MGMarkus G.Verified BuyerReviewingSquare D LH36400 - 400A 3 Pole Molded Case Circuit BreakerI recommend this productRated 5 out of 5 stars11/4/25it states correctly what it was
Product as described