Square D LLL36400CU31X Molded Case Circuit Breaker
- 400A
- 3 Pole
- Unit Mount
Quantity
Square D LLL36400CU31X - 400A 3 Pole Molded Case Circuit Breaker
New
Quantity
Description
Built for heavy-duty industrial control panels and enclosures, this 400A PowerPacT L-Frame breaker carries a 100% continuous current rating. It installs via standard unit mounting into motor control centers and standalone switchboards. The onboard MicroLogic 3.3 electronic trip unit delivers highly accurate LI protection, while the 100kA interrupting capacity at 480VAC ensures robust defense against severe fault currents in commercial facilities.Specifications
| Brand | Square D |
|---|---|
| Series | LLL |
| Amperage | 400A |
| Poles | 3 |
| Mounting Style | Unit Mount |
| Voltage | 240VAC, 480VAC, 600VAC, 250VDC |
| Phase | 3 |
| AIC Rating | 125kA @ 240VAC, 100kA @ 480VAC, 50kA @ 600VAC, 20kA @ 250VDC |
| Amperage Range | 125-400A |
|---|
| Frame Type | LLL |
|---|---|
| Terminal Type | Lugs |
| For Use With | Square D Switchboards, Motor Control Centers, Industrial Control Panels, 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, Padlock Attachment, Motor Operator, Rotary Handle |
|---|---|
| Accessories | MicroLogic 3.3 Trip Unit |
| Standards | CSA C22.2 No 5, IEC 60947-2, NEMA AB 1, UL 489 |
| Approval | CCC, CE, CSA, IEC, NEMA, NOM, UL, UKCA |
| Temp Rating | -25C to 70C |
| Construction Features | HACR Rated, Current Limiting, True RMS Sensing, Visual Trip Indicator, 100% Rated, Mercury Free, RoHS Compliant, PVC Free |
Product FAQs
9 answersDoes the "C" in LLL36400CU31X mean it is 100% rated?
Yes, the "C" designates a 100% continuous current rating. To utilize this full 400A continuous rating, the breaker must be installed in a properly sized enclosure using 90 degrees C rated wire sized to the 75 degrees C ampacity chart.
Can I use the LLL36400CU31X in an I-Line panelboard?
No, this is a unit-mount breaker designed for feed-thru lug connections on both the line and load sides. For an I-Line plug-on panelboard, you would need an I-Line version such as the LLA36400CU31X.
What protection settings are adjustable on the MicroLogic 3.3 trip unit?
The MicroLogic 3.3 (U31X) electronic trip unit provides adjustable Long-Time (L) protection for overload conditions and Instantaneous (I) protection for short circuits. It does not include Short-Time (S) or Ground Fault (G) protection.
Can the LLL36400CU31X replace older Square D L-frame breakers?
Yes, the PowerPacT L-frame is designed to replace legacy Square D L-frame breakers of the same physical size and mounting configuration. However, you must verify that the interrupting rating and 100% continuous current rating match or exceed your system requirements.
What is the difference between the LLL36400CU31X and the LGL36400CU31X?
The difference lies in the interrupting rating. The LLL model features an "L" interrupting class (100kA at 480VAC), whereas the LGL model features a "G" interrupting class (35kA at 480VAC). Both share the same physical dimensions, mounting style, and 100% continuous current rating.
Can the LLL36400CU31X be reverse fed?
Yes, PowerPacT L-frame breakers with standard MicroLogic 3.3 trip units are suitable for reverse feeding (backfeeding). Always verify your specific local code requirements and panelboard labeling before reverse feeding.
Does this breaker have a manual trip feature for testing?
Yes, all PowerPacT L-frame circuit breakers feature an integral push-to-trip button on the cover. This allows you to manually trip the breaker to verify the mechanical operation of the trip mechanism.
Can I add a shunt trip or auxiliary switch to the LLL36400CU31X?
Yes, the PowerPacT L-frame supports field-installable internal accessories, including shunt trips, undervoltage releases, and auxiliary switches. These install behind the front accessory cover.
Does the MicroLogic 3.3 trip unit require an external power supply?
No, the MicroLogic 3.3 trip unit is self-powered by the current flowing through the circuit breaker. It does not require an external power source to provide its standard Long-Time and Instantaneous protection functions.
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