Square D MXL36400 Molded Case Circuit Breaker
- 400A
- 3 Pole
- Unit Mount
Quantity
Square D MXL36400 - 400A 3 Pole Molded Case Circuit Breaker
New
Quantity
Description
Built for industrial applications, the Square D MXL36400 is a 3-pole, 400A molded case circuit breaker utilizing an advanced electronic trip unit. This unit-mount breaker fits Square D switchboards and motor control centers. It is replaced by the modern PowerPacT L-Frame (LJL36400U33X), which requires a retrofit kit. Featuring a 65kAIC rating at 480V, it delivers adjustable long-time, short-time, and instantaneous (LSI) trip functions for precise coordination.Specifications
| Brand | Square D |
|---|---|
| Part Number | MXL36400 |
| Series | MXL |
| Amperage | 400A |
| Poles | 3 |
| Mounting Style | Unit Mount |
| Voltage | 240VAC, 480VAC, 600VAC |
| Phase | 3 |
| AIC Rating | 65kA @ 240VAC, 65kA @ 480VAC, 25kA @ 600VAC |
| Amperage Range | 200-400A |
|---|
| Frame Type | MXL |
|---|---|
| Terminal Type | Lugs |
| For Use With | Square D Switchboards, Motor Control Centers |
| 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 | LSI |
| Trip Function | Long-Time, Short-Time, Instantaneous |
| Trip Adjustability | Adjustable |
| Available Options | Shunt Trip, Auxiliary Switch, Undervoltage Release, Alarm Switch |
|---|---|
| Accessories | Micrologic Trip Unit, Lugs |
| Standards | CSA C22.2 No. 5, HACR, UL 489 |
| Approval | CSA, UL |
| Temp Rating | 40C |
| Construction Features | HACR Rated, High Interrupting Capacity, Non-Interchangeable Trip |
Product FAQs
5 answersWhat wire sizes are compatible with the lugs on the MXL36400?
The standard lugs on this breaker accept up to three 3/0 AWG to 500 kcmil aluminum or copper conductors per phase.
Is this breaker designed for plug-on I-Line panelboards?
No, the MXL36400 is a unit mount, feed-thru circuit breaker. It is typically installed in Square D switchboards and motor control centers rather than I-Line distribution panels.
What does the LSI designation mean on this breaker's trip unit?
LSI indicates the electronic trip unit features adjustable Long-Time, Short-Time, and Instantaneous pickup settings. This allows electricians to precisely coordinate the breaker's response with other protective devices in the electrical system.
Is the MXL36400 part of a current Square D product line?
The MXL series is a legacy molded case circuit breaker. While it remains widely used for direct replacements in existing switchboards, Schneider Electric generally recommends the PowerPact series for completely new installations.
What precautions are required when adjusting the LSI settings?
Adjustments to the electronic trip unit should only be performed by a qualified electrician following a formal coordination study. Incorrect settings can compromise system protection against overloads and short circuits.
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