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Square D LDL36400CU31X Molded Case Circuit Breaker
- 400A
- 3 Pole
- Unit Mount
Square D
LDL36400CU31X
Molded Case Circuit Breaker
Brand
Square D
SKU
LDL36400CU31X
Quantity
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Square D LDL36400CU31X - 400A 3 Pole Molded Case Circuit Breaker
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Description
Built for industrial environments, the Square D LDL36400CU31X is a 400A PowerPacT L-Frame MCCB. It features a MicroLogic 3.3 electronic trip unit for configurable LI protection. This unit-mount breaker installs into compatible switchboards and control panels. It includes line and load lugs for dual 2/0 AWG to 500 kcmil wire. Rated for 100% continuous current, it maximizes capacity in critical applications while delivering an 18kAIC interrupt rating at 480VAC.Specifications
| Brand | Square D |
|---|---|
| Part Number | LDL36400CU31X |
| Series | LDL |
| Amperage | 400A |
| Poles | 3 |
| Mounting Style | Unit Mount |
| Voltage | 240VAC, 480VAC, 600VAC, 250VDC |
| Phase | 3 |
| AIC Rating | 25kA @ 240VAC, 18kA @ 480VAC, 14kA @ 600VAC, 20kA @ 250VDC |
| Amperage Range | 125-400A |
|---|
| Frame Type | LDL |
|---|---|
| Terminal Type | Lugs |
| For Use With | Industrial Control Panels, Switchboards, Enclosures |
| Wire Gauge | (2) 2/0 AWG-500 kcmil (Al/Cu) |
| Max Wire | 500 kcmil |
| Min Wire | 2/0 AWG |
| Trip Technology | Electronic Trip |
|---|---|
| Trip Function Code | LI |
| Trip Function | Long-Time, Instantaneous |
| Trip Adjustability | Adjustable |
| Available Options | Shunt Trip, Auxiliary Switch, Undervoltage Release, Alarm Switch, Motor Operator, Rotary Handle, Padlock Attachment |
|---|---|
| Accessories | Line and Load Lugs Included |
| Standards | CSA C22.2 No. 5, IEC 60947-2, NEMA AB1, UL 489 |
| Approval | CCC, CE, CSA, IEC, NEMA, NOM, UL |
| Temp Rating | -25C to 70C |
| Construction Features | HACR Rated, True RMS Sensing, 100% Rated |
Product FAQs
8 answersIs the LDL36400CU31X rated for 100 percent continuous current?
Yes, the C in the catalog number indicates this breaker is 100 percent rated. This allows it to carry its full 400A continuous current without the standard 80 percent derating, provided it is installed in a properly sized and ventilated enclosure.
What type of trip unit is included with the LDL36400CU31X?
This breaker features a MicroLogic 3.3 electronic trip unit, indicated by the U31X suffix. It provides adjustable Long-Time and Instantaneous (LI) protection settings for precise system coordination.
Does the MicroLogic 3.3 trip unit feature True RMS sensing?
Yes, the solid-state electronic trip unit provides True RMS sensing. This ensures accurate current measurement and reliable protection even in electrical systems with high harmonic distortion.
How does the LDL36400CU31X mount into an electrical panel?
This is a unit-mount circuit breaker. It bolts directly to the backpan or mounting surface of industrial control panels, switchboards, or enclosures, rather than plugging onto a busbar like I-Line models.
What wire sizes are accepted by the lugs on this 400A L-Frame breaker?
The factory-installed line and load lugs accept two 2/0 AWG to 500 kcmil aluminum or copper conductors per phase.
Can this PowerPacT L-Frame breaker be used in DC applications?
Yes, the LDL36400CU31X is rated for up to 250VDC with a 20kA interrupting rating, making it suitable for specific direct current control panels and battery systems.
Is this 400A breaker HACR rated for HVAC equipment?
Yes, Square D PowerPacT L-Frame molded case circuit breakers are HACR rated, meaning they are approved for use with commercial heating, air conditioning, and refrigeration equipment.
Can I use this breaker to replace an older Square D L-Frame MCCB?
Yes, the PowerPacT L-Frame is designed to fit the same footprint as many legacy Square D L-Frame breakers. You must verify that your existing panel accepts unit-mount configurations and matches the 18kA at 480VAC interrupting rating.
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