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Square D MJA36300 Molded Case Circuit Breaker
- 300A
- 3 Pole
- I-Line
Square D
MJA36300
Molded Case Circuit Breaker
Brand
Square D
SKU
MJA36300
Quantity
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Square D MJA36300 - 300A 3 Pole Molded Case Circuit Breaker
New
Quantity
Quantity
Square D MJA36300 - 300A 3 Pole Molded Case Circuit Breaker
New
Quantity
| Brand | Square D |
|---|---|
| Series | MJA |
| Amperage | 300A |
| Poles | 3 |
| Mounting Style | I-Line |
| Voltage | 240VAC, 480VAC, 600VAC |
| Phase | 3 |
| AIC Rating | 100kA @ 240VAC, 65kA @ 480VAC, 25kA @ 600VAC |
| Frame Type | MJA |
|---|---|
| Terminal Type | Lugs |
| For Use With | Square D I-Line Panelboards, Switchboards |
| Wire Gauge | (3) 3/0 AWG-500 kcmil (Al/Cu) |
| Max Wire | 500 kcmil |
| Min Wire | 3/0 AWG |
| Trip Technology | Electronic Trip |
|---|---|
| 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, Rotary Handle, Lug Kits |
|---|---|
| Accessories | Lugs (AL800M23K) |
| Standards | CSA C22.2 No. 5, HACR, IEC 60947-2, NEMA AB 1, NOM-003-SCFI-2000, UL 489 |
| Approval | CE, CSA, IEC, NOM, UL |
| Temp Rating | -25C to 70C |
| Construction Features | Current Limiting, HACR Rated, Non-Interchangeable Trip, 80% Rated, Mercury Free, PVC Free, Push-to-Trip |
Quantity
Square D MJA36300 - 300A 3 Pole Molded Case Circuit Breaker
Re-Certified
Quantity
| Brand | Square D |
|---|---|
| Series | MJA |
| Amperage | 300A |
| Poles | 3 |
| Mounting Style | I-Line |
| Voltage | 240VAC, 480VAC, 600VAC |
| Phase | 3 |
| AIC Rating | 100kA @ 240VAC, 65kA @ 480VAC, 25kA @ 600VAC |
| Frame Type | MJA |
|---|---|
| Terminal Type | Lugs |
| For Use With | Square D I-Line Panelboards, Switchboards |
| Wire Gauge | (3) 3/0 AWG-500 kcmil (Al/Cu) |
| Max Wire | 500 kcmil |
| Min Wire | 3/0 AWG |
| Trip Technology | Electronic Trip |
|---|---|
| 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, Rotary Handle, Lug Kits |
|---|---|
| Accessories | Lugs (AL800M23K) |
| Standards | CSA C22.2 No. 5, HACR, IEC 60947-2, NEMA AB 1, NOM-003-SCFI-2000, UL 489 |
| Approval | CE, CSA, IEC, NOM, UL |
| Temp Rating | -25C to 70C |
| Construction Features | Current Limiting, HACR Rated, Non-Interchangeable Trip, 80% Rated, Mercury Free, PVC Free, Push-to-Trip |
Similar Items
350A 3 Pole Molded Case Circuit Breaker
400A 3 Pole Molded Case Circuit Breaker
450A 3 Pole Molded Case Circuit Breaker
Description
Operating as a 300A, 3-pole molded case circuit breaker, the MJA36300 belongs to the Square D PowerPacT M-Frame series. It is built for commercial and industrial electrical distribution systems. This unit mounts into Square D I-Line panelboards and switchboards. It also serves as a reliable replacement for legacy MA and MH frame breakers, simplifying facility upgrades. Equipped with an ET 1.0 electronic trip unit, it provides precise LI protection. It features a 65kAIC rating at 480VAC.Specifications
| Brand | Square D |
|---|---|
| Series | MJA |
| Amperage | 300A |
| Poles | 3 |
| Mounting Style | I-Line |
| Voltage | 240VAC, 480VAC, 600VAC |
| Phase | 3 |
| AIC Rating | 100kA @ 240VAC, 65kA @ 480VAC, 25kA @ 600VAC |
| Frame Type | MJA |
|---|---|
| Terminal Type | Lugs |
| For Use With | Square D I-Line Panelboards, Switchboards |
| Wire Gauge | (3) 3/0 AWG-500 kcmil (Al/Cu) |
| Max Wire | 500 kcmil |
| Min Wire | 3/0 AWG |
| Trip Technology | Electronic Trip |
|---|---|
| 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, Rotary Handle, Lug Kits |
|---|---|
| Accessories | Lugs (AL800M23K) |
| Standards | CSA C22.2 No. 5, HACR, IEC 60947-2, NEMA AB 1, NOM-003-SCFI-2000, UL 489 |
| Approval | CE, CSA, IEC, NOM, UL |
| Temp Rating | -25C to 70C |
| Construction Features | Current Limiting, HACR Rated, Non-Interchangeable Trip, 80% Rated, Mercury Free, PVC Free, Push-to-Trip |
Product FAQs
7 answersWhat type of panelboards does the MJA36300 fit?
This breaker features an I-Line plug-on connection on the line side and is built exclusively for use in Square D I-Line panelboards and switchboards.
Can the MJA36300 replace legacy Square D breakers?
Yes, this PowerPacT M-frame breaker serves as a direct, reliable replacement for older legacy MA and MH frame I-Line circuit breakers.
Is the MJA36300 circuit breaker suitable for reverse feeding?
No. Because it utilizes a specialized I-Line plug-on jaw connection on the line side, it cannot be safely reverse fed.
What is the wire capacity for the load lugs on the MJA36300?
The standard factory-installed load lugs accept up to three 3/0 AWG to 500 kcmil aluminum or copper conductors per phase.
How does the ET 1.0 electronic trip unit function on this breaker?
The ET 1.0 basic electronic trip unit provides LI protection. The long-time overload setting is fixed at 300A, while the instantaneous short-circuit trip setting is adjustable.
What does the "J" in the MJA36300 catalog number indicate?
The "J" designates the breaking capacity level for this M-frame breaker, indicating an interrupting rating of 100 kAIC at 240VAC, 65 kAIC at 480VAC, and 25 kAIC at 600VAC.
Does the MJA36300 offer equipment ground-fault protection?
No. It is equipped with an LI (Long-Time and Instantaneous) basic electronic trip unit and does not include ground-fault or short-time protection functions.
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