Built for industrial power distribution, the Square D NX361000 is a 3-pole, 1000A molded case circuit breaker featuring a Micrologic Series B solid-state trip unit. It mounts into Square D I-Line panelboards and switchboards. While often replaced by the PowerPacT PLA34100U33A in new builds, this NX frame is ideal for maintaining existing infrastructure. Rated 100 kAIC at 480V, it delivers robust fault clearing. Adjustable LSI settings allow engineers to fine-tune the protection curve.
Shunt Trip, Auxiliary Switch, Bell Alarm, Undervoltage Release, Padlock Attachment
Accessories
Load Side Lugs
Standards
CSA C22.2 No. 5, IEC 60947-2, NEMA AB 1, UL 489
Approval
CSA, IEC, UL
Temp Rating
40C
Construction Features
HACR Rated, Solid State Trip Unit, Micrologic Series B, Non-Interchangeable Trip, True RMS Sensing
Product FAQs
5 answers
What type of panels are compatible with the NX361000?
This breaker features an I-Line style plug-in connection and is exclusively compatible with Square D I-Line panelboards and switchboards. It will not fit standard NQ, NF, or QO load centers.
What are the wire size requirements for the NX361000 lugs?
The terminal lugs accommodate four conductors per phase, accepting wire sizes from 3/0 AWG up to 600 kcmil. The lugs are rated for both aluminum and copper (Al/Cu) wire.
How does the LSI trip unit function on this breaker?
The electronic trip unit features adjustable Long-Time, Short-Time, and Instantaneous (LSI) settings. This allows engineers and panel builders to fine-tune the protection curve for precise selective coordination with other breakers in the electrical system.
Is the Square D NX frame still manufactured, or is there a direct replacement?
The NX frame is a legacy molded case circuit breaker. While it is still widely used to maintain existing infrastructure, new installations typically use the Square D PowerPact P-frame series (such as the PLA34100U33A) as the modern equivalent for 1000A I-Line applications.
Does the NX361000 require a separate mounting bracket for installation?
No. It utilizes a self-contained I-Line style plug-in connection that mounts directly onto the busbar of an I-Line panelboard or switchboard without requiring additional mounting hardware.
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.