Square D LRA36400U33X Molded Case Circuit Breaker
- 400A
- 3 Pole
- I-Line
Quantity
Square D LRA36400U33X - 400A 3 Pole Molded Case Circuit Breaker
New
Quantity
Description
Built for heavy-duty industrial applications, the Square D LRA36400U33X is a 3-pole, 400A molded case circuit breaker from the PowerPacT L-Frame family. This breaker utilizes an I-Line plug-on connection, enabling rapid installation into compatible Square D I-Line panelboards and switchboards. The load side features standard mechanical lugs. The standout feature of this model is its ultra-high interrupting capacity of 200 kAIC at 480VAC. It includes a MicroLogic 3.3S electronic trip unit.Specifications
| Brand | Square D |
|---|---|
| Series | LRA |
| Amperage | 400A |
| Poles | 3 |
| Mounting Style | I-Line |
| Voltage | 240VAC, 480VAC, 600VAC |
| Phase | 3 |
| AIC Rating | 200kA @ 240VAC, 200kA @ 480VAC, 100kA @ 600VAC |
| Amperage Range | 125-400A |
|---|
| Frame Type | LRA |
|---|---|
| Terminal Type | Lugs |
| For Use With | Square D I-Line Panelboards, Switchboards |
| 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 | LSI |
| Trip Function | Long-Time, Short-Time, Instantaneous |
| Trip Adjustability | Adjustable |
| Available Options | Shunt Trip, Auxiliary Switch, Undervoltage Release, Alarm Switch, Padlock Attachment, Motor Operator |
|---|---|
| Accessories | MicroLogic 3.3S 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, 80% Rated, Reverse Feed, Visual Trip Indicator, Quick-Make/Quick-Break |
Product FAQs
7 answersWhat type of panelboards are compatible with the LRA36400U33X circuit breaker?
This breaker is designed exclusively for Square D I-Line power distribution panelboards and switchboards. It features an I-Line style plug-in connection that mounts directly onto the panel bus assembly.
Can I install this PowerPact L-frame breaker in an older I-Line panelboard?
Yes, Schneider Electric has confirmed that PowerPact L-frame breakers are backwards compatible with older, previously installed Square D I-Line panelboards and switchboards, provided the voltage and short-circuit ratings meet your system requirements.
What does the U33X suffix in the LRA36400U33X catalog number indicate?
The U33X suffix designates that the breaker is equipped with a Micrologic 3.3S electronic trip unit. This provides adjustable LSI (Long-Time, Short-Time, and Instantaneous) protection functions, allowing panel builders to precisely coordinate the breaker with other devices in the electrical system.
What does the R in the LRA36400U33X part number represent?
The R indicates the interrupting rating tier of the PowerPact L-frame. In this case, it signifies a high interrupting capacity of 200kA at 480VAC, making it suitable for industrial environments with high available fault currents.
How does the I-Line connection on the LRA36400U33X simplify installation?
The I-Line plug-in design allows the breaker to mount directly onto the panel bus assembly. This eliminates the need for line-side wiring and wire-bending space, significantly reducing installation time in compatible Square D switchboards and panelboards.
What size wire can be used with the standard lugs on the LRA36400U33X?
The factory-installed mechanical lugs on this 400A breaker accept two 2/0 AWG to 500 kcmil aluminum or copper conductors per phase, providing flexibility for various heavy-duty feeder applications.
What is the advantage of the solid-state electronic trip unit on this breaker?
The Micrologic electronic trip unit provides higher accuracy and repeatability compared to traditional thermal-magnetic breakers. The adjustable Long-Time and Short-Time settings allow electricians to closely match the breaker protection curve to the specific load, reducing the risk of nuisance tripping.
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