Engineered for commercial and industrial applications, the Square D LJA36400CU33X is a 3-pole, 400A PowerPacT L-Frame MCCB. It provides advanced protection with a 100% continuous current rating. This breaker installs into Square D I-Line panelboards and switchboards, featuring an I-Line connection on the line side and mechanical lugs on the load side. Rated 65 kAIC at 480VAC, it utilizes a MicroLogic 3.3S electronic trip unit with adjustable LSI settings for precise coordination.
What does the "C" indicate in the LJA36400CU33X catalog number?
The "C" signifies that this PowerPacT breaker has a 100% continuous current rating. When installed in an appropriately sized enclosure with 90 degrees Celsius rated wire, it can safely carry its full 400A capacity without the standard 80% derating limit.
What specific trip unit comes installed on the LJA36400CU33X?
The "U33X" suffix indicates this breaker includes a factory-installed MicroLogic 3.3S electronic trip unit. This solid state unit offers field-adjustable Long-Time, Short-Time, and Instantaneous (LSI) protection settings to optimize electrical coordination.
How does this I-Line breaker connect to the panelboard?
This breaker features plug-on jaw connections on the line side that mount directly to the busbars of an I-Line panelboard or switchboard. The load side is equipped with mechanical lugs for outgoing wire terminations.
Is this circuit breaker compatible with legacy I-Line panelboards?
Yes, it uses the standardized Square D I-Line plug-on mounting system, making it backward compatible with most older and current-generation Square D I-Line panelboards and switchboards.
Can I install a shunt trip or auxiliary switch on this L-Frame breaker?
Yes, PowerPacT L-Frame breakers are designed to accept a variety of field-installable internal accessories. Shunt trips, undervoltage releases, and auxiliary contacts can be added beneath the front accessory cover.
SuperClub
Join free. Get 500 SuperPoints.
Earn points on eligible purchases and redeem them at checkout.
We source obsolete and hard-to-find parts every day.
Shipping
Free Shipping Policy
Parcel shipments with item value over $99 qualify for free economy shipping within the continental US. Please call to confirm special handling instructions. We do not charge a handling fee or require a minimum amount on any order. SuperBreakers does not ship on customer accounts.
We strive to ship out your items the same day the order is placed. In rare circumstances SuperBreakers may reserve up to 5 business days to consolidate orders for complete shipment.
Expedited Shipments
Orders being shipped via Next Day Air, 2 Day Shipping or 3 Day Shipping must be received by 3 PM EST to guarantee same-day shipments. Expedited orders only ship on normal business days. Shipments will NOT be sent out on Saturdays and Sundays.
International Shipping
All International orders require a $1,000 minimum order threshold. Due to the special nature of these shipments, we require that these be placed with a SuperBreakers representative. Additional shipping and instructions will apply. All International Orders are Non-Cancel and Non-Refundable.