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Square D MHL36300 Molded Case Circuit Breaker
- 300A
- 3 Pole
- Unit Mount
Square D
MHL36300
Molded Case Circuit Breaker
Brand
Square D
SKU
MHL36300
Quantity
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Square D MHL36300 - 300A 3 Pole Molded Case Circuit Breaker
Re-Certified
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Square D MHL36300 - 300A 3 Pole Molded Case Circuit Breaker
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| Brand | Square D |
|---|---|
| Part Number | MHL36300 |
| Series | MHL |
| Amperage | 300A |
| Poles | 3 |
| Mounting Style | Unit Mount |
| Voltage | 600VAC, 250VDC |
| Phase | 3 |
| AIC Rating | 65kA @ 240VAC, 65kA @ 480VAC, 25kA @ 600VAC, 14kA @ 250VDC |
| Frame Type | MHL |
|---|---|
| Terminal Type | Lugs |
| For Use With | Square D Switchboards, Motor Control Centers, Enclosures |
| Wire Gauge | (3) 3/0 AWG - 500 kcmil (Al/Cu) |
| Max Wire | 500 kcmil |
| Min Wire | 3/0 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, Undervoltage Release, Alarm Switch, Padlock Attachment |
|---|---|
| Accessories | Lugs (AL900MA) |
| Standards | CSA C22.2 No. 5, NEMA AB 1, UL 489 |
| Approval | CSA, HACR, UL |
| Temp Rating | 40C |
| Construction Features | HACR Rated, High Interrupting Capacity, Non-Interchangeable Trip |
Quantity
Square D MHL36300 - 300A 3 Pole Molded Case Circuit Breaker
Re-Certified
Quantity
| Brand | Square D |
|---|---|
| Series | MHL |
| Amperage | 300A |
| Poles | 3 |
| Mounting Style | Unit Mount |
| Voltage | 600VAC, 250VDC |
| Phase | 3 |
| AIC Rating | 65kA @ 240VAC, 65kA @ 480VAC, 25kA @ 600VAC, 14kA @ 250VDC |
| Frame Type | MHL |
|---|---|
| Terminal Type | Lugs |
| For Use With | Square D Switchboards, Motor Control Centers, Enclosures |
| Wire Gauge | (3) 3/0 AWG - 500 kcmil (Al/Cu) |
| Max Wire | 500 kcmil |
| Min Wire | 3/0 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, Undervoltage Release, Alarm Switch, Padlock Attachment |
|---|---|
| Accessories | Lugs (AL900MA) |
| Standards | CSA C22.2 No. 5, NEMA AB 1, UL 489 |
| Approval | CSA, HACR, UL |
| Temp Rating | 40C |
| Construction Features | HACR Rated, High Interrupting Capacity, Non-Interchangeable Trip |
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Description
Built for commercial applications, the Square D MHL36300 is a 300A, 3-pole molded case circuit breaker. It utilizes standard thermal-magnetic trip technology, offering fixed thermal and adjustable magnetic (LI) protection to safeguard critical infrastructure. This unit-mount MCCB is designed to fit Square D switchboards, motor control centers, and standalone enclosures. It provides a high interrupting capacity of 65kA at 480VAC.Specifications
| Brand | Square D |
|---|---|
| Series | MHL |
| Amperage | 300A |
| Poles | 3 |
| Mounting Style | Unit Mount |
| Voltage | 600VAC, 250VDC |
| Phase | 3 |
| AIC Rating | 65kA @ 240VAC, 65kA @ 480VAC, 25kA @ 600VAC, 14kA @ 250VDC |
| Frame Type | MHL |
|---|---|
| Terminal Type | Lugs |
| For Use With | Square D Switchboards, Motor Control Centers, Enclosures |
| Wire Gauge | (3) 3/0 AWG - 500 kcmil (Al/Cu) |
| Max Wire | 500 kcmil |
| Min Wire | 3/0 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, Undervoltage Release, Alarm Switch, Padlock Attachment |
|---|---|
| Accessories | Lugs (AL900MA) |
| Standards | CSA C22.2 No. 5, NEMA AB 1, UL 489 |
| Approval | CSA, HACR, UL |
| Temp Rating | 40C |
| Construction Features | HACR Rated, High Interrupting Capacity, Non-Interchangeable Trip |
Product FAQs
6 answersWhat is the adjustable magnetic trip range for the MHL36300?
The MHL36300 features a fixed thermal and adjustable magnetic trip unit. The instantaneous magnetic trip threshold can be adjusted from a low setting of 1500A to a high setting of 3000A to coordinate with downstream loads and fault current calculations.
Can the Square D MHL36300 be reverse fed?
Yes. Because this thermal-magnetic circuit breaker does not have restrictive LINE and LOAD markings, it can be reverse fed safely in standard distribution applications.
Is the MHL36300 compatible with I-Line panelboards?
No. The MHL36300 is a unit-mount, feed-thru circuit breaker designed to be bolted to a backpan in switchboards, motor control centers, or individual enclosures. It does not have the plug-on jaw connections required for I-Line bus systems.
What is the modern replacement for the legacy MHL36300?
The Square D M-frame is a legacy product. For new installations or complete retrofits, Schneider Electric typically recommends the PowerPact L-frame series. Note that upgrading to a PowerPact breaker will require modifications to the mounting hardware and enclosure space.
What protection does the LI trip function provide on this breaker?
The LI designation means the breaker provides Long-Time (L) thermal protection against sustained overloads and Instantaneous (I) magnetic protection against short circuits. The thermal element is fixed, while the magnetic element is adjustable.
How many conductors can the standard lugs on the MHL36300 accommodate?
The standard factory-installed mechanical lugs are designed to accept up to three aluminum or copper conductors per phase, with a wire range of 3/0 AWG to 500 kcmil. Always verify the specific lug catalog number on the breaker faceplate, as field-installed lug kits may vary.
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