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Square D MJA36450 Molded Case Circuit Breaker
- 450A
- 3 Pole
- I-Line
Square D
MJA36450
Molded Case Circuit Breaker
Brand
Square D
SKU
MJA36450
Quantity
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Square D MJA36450 - 450A 3 Pole Molded Case Circuit Breaker
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Description
The MJA36450 is a 450A molded case circuit breaker from Square D's PowerPacT M-Frame family. It utilizes an ET 1.0 electronic trip unit to deliver accurate long-time and instantaneous (LI) protection for industrial applications. This unit installs into Square D I-Line panelboards and switchboards, serving as a reliable replacement for discontinued MA and MH frame breakers. Rated 65kAIC at 480V, its microprocessor sensing offers superior coordination over standard thermal-magnetic options.Specifications
| Brand | Square D |
|---|---|
| Series | MJA |
| Amperage | 450A |
| 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 | 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 |
|---|---|
| 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, 80% Rated, Push-to-Trip, Non-Interchangeable Trip, Visual Trip Indicator, Trip-Free Mechanism, Quick-Make/Quick-Break |
Product FAQs
6 answersWhat type of panelboards accept the MJA36450 breaker?
This breaker features an I-Line plug-on connection, making it compatible with Square D I-Line panelboards and switchboards. The line side plugs directly into the bus, while the load side uses traditional lugs.
What does the J in the MJA36450 catalog number indicate?
The J designates the interrupting rating tier within the PowerPacT M-frame family. It provides 100kA at 240V, 65kA at 480V, and 25kA at 600V, which sits between the standard G tier and the higher L tier.
What wire sizes are accepted by the load side lugs on this breaker?
The factory-installed lugs accept three conductors per phase, ranging from 3/0 AWG to 500 kcmil for either aluminum or copper wire. Ensure proper torque specifications are followed during installation.
How does the LI electronic trip unit function on this 450A breaker?
The LI designation means the solid-state trip unit provides Long-time (L) and Instantaneous (I) protection. It does not include Short-time or Ground-fault functions. The electronic trip offers more precise coordination than traditional thermal-magnetic units.
Does the MJA36450 require a specific mounting bracket for installation?
No additional mounting bracket is required for standard I-Line panelboard installation. The breaker features built-in mounting jaws on the line side that secure directly to the I-Line bus assembly.
Can I use the MJA36450 to replace an MGA36450?
Yes, the MJA36450 has the same physical dimensions and mounting footprint as the MGA36450. It serves as a direct upgrade, offering a higher interrupting capacity (65kA at 480V versus 35kA for the G-tier).
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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
- JKJosh K.ReviewingSquare D MJA36800 - 800A 3 Pole Molded Case Circuit BreakerI recommend this productRated 5 out of 5 stars3/12/21Great Price
Great breaker and Price.
- KPKevin P.ReviewingSquare D MJA36500 - 500A 3 Pole Molded Case Circuit BreakerI recommend this productRated 5 out of 5 stars1/26/21Easy to order
Easy to order with good pricing!