Square D LA364001021 Molded Case Circuit Breaker
- 400A
- 3 Pole
- I-Line
Quantity
Square D LA364001021 - 400A 3 Pole Molded Case Circuit Breaker
New
Quantity
Description
Built for advanced control, the Square D LA364001021 is a 3-pole, 400A legacy L-Frame circuit breaker featuring a factory-installed 120-240VAC shunt trip. This allows facility managers to remotely open the circuit for enhanced safety and automation. The breaker mounts into standard Square D I-Line panelboards and switchboards. When transitioning to newer equipment, it crosses over to the PowerPacT LJA36400U31XSA. It delivers 42kAIC at 240V and includes an adjustable magnetic trip mechanism.Specifications
| Brand | Square D |
|---|---|
| Series | LA |
| Amperage | 400A |
| Poles | 3 |
| Mounting Style | I-Line |
| Voltage | 240VAC, 480VAC, 600VAC, 250VDC |
| Phase | 3 |
| AIC Rating | 42kA @ 240VAC, 30kA @ 480VAC, 22kA @ 600VAC, 10kA @ 250VDC |
| Frame Type | LA |
|---|---|
| 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 | Auxiliary Switch, Undervoltage Release, Alarm Switch, Padlock Attachment |
|---|---|
| Accessories | Shunt Trip (120-240VAC) |
| Standards | CSA C22.2 No. 5, HACR, IEC 60947-2, UL 489 |
| Approval | CSA, IEC, UL |
| Temp Rating | 40C |
| Construction Features | HACR Rated, Visual Trip Indicator |
Product FAQs
8 answersWhat panelboards accept the LA364001021 circuit breaker?
This breaker is designed exclusively for Square D I-Line panelboards and switchboards. It uses an I-Line plug-in connection to attach directly to the busbar.
What does the 1021 suffix indicate on this Square D breaker?
The 1021 suffix means the LA364001021 comes with a factory-installed 120/240VAC shunt trip. This allows the breaker to be tripped remotely by applying voltage to the shunt trip coil.
What wire sizes are supported by the load lugs on the LA364001021?
The load side lugs accept either a single 1 AWG to 600 kcmil conductor or two 1 AWG to 250 kcmil conductors. The terminals are rated for both aluminum and copper wire.
How does the interrupting rating change based on the system voltage?
The maximum interrupting capacity is 42kA at 240VAC. This drops to 30kA at 480VAC, 22kA at 600VAC, and 10kA when used on a 250VDC system.
Is the trip unit on this 400A breaker adjustable?
The LA364001021 features a thermal magnetic trip unit with a fixed thermal element for long-time overload protection and an adjustable magnetic element for instantaneous short-circuit protection.
How can I safely test the mechanical operation of this breaker?
Square D LA frame breakers feature a push-to-trip button on the front face. This allows licensed electricians to manually exercise the tripping mechanism without exposure to live electrical parts.
Can the LA364001021 be used in direct current systems?
Yes, this molded case circuit breaker is rated for use in DC systems up to 250VDC, where it provides a 10kA interrupting rating.
Does this breaker require bolt-on connections to the busbar?
No, the LA364001021 uses an I-Line plug-in mounting style for the line side. It snaps directly onto the I-Line bus structure, while the load side uses standard wire lugs.
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Reviews
Review summary
Customers rate this product 5.0 out of 5 based on 13 reviews.
- RGRobert G.Verified BuyerReviewingSquare D LA36400 - 400A 3 Pole Molded Case Circuit BreakerI recommend this productRated 5 out of 5 stars7/16/26LA36400
Perfectly boxed and arrived on time. Thanks for the shirt and stickers as well.
- CECraig E.Verified BuyerReviewingEaton / Cutler-Hammer LA3600 - 600A 3 Pole Molded Case Circuit BreakerI recommend this productRated 5 out of 5 stars10/13/25Westinghouse breaker
Excellent customer service and quick shipping
- CLClifton L.Verified BuyerReviewingSquare D LA36400 - 400A 3 Pole Molded Case Circuit BreakerI recommend this productRated 5 out of 5 stars9/30/25estimator
Good
- BCBenjamin C.Verified BuyerReviewingEaton / Cutler-Hammer LA3225 - 225A 3 Pole Molded Case Circuit BreakerI recommend this productRated 5 out of 5 stars8/4/25Refurbished Breaker
Breaker seems to be working great, no complaints from Client
- JMJerry M.ReviewingEaton / Cutler-Hammer LA3400 - 400A 3 Pole Molded Case Circuit BreakerI recommend this productRated 5 out of 5 stars3/14/23Where is my breaker?
Where is my breaker?