Skip to main content

Square D FJA34040 Molded Case Circuit Breaker

  • 40A
  • 3 Pole
  • I-Line
Square D FJA34040
Molded Case Circuit Breaker
Brand Square D
SKU FJA34040
Select Item Condition
Earn 473 SuperPoints
  • 40A
  • 3 Pole
  • I-Line

Quantity

Bulk Pricing
Send your parts list for a volume quote.
Square D FJA34040 - 40A 3 Pole Molded Case Circuit Breaker

Square D FJA34040 - 40A 3 Pole Molded Case Circuit Breaker

Re-Certified

$473.98 No Stock

Quantity

Description

Engineered for robust commercial applications, the Square D FJA34040 is a 3-pole, 40A molded case circuit breaker. It features fixed thermal-magnetic trip units providing long-time and instantaneous (LI) protection for industrial electrical systems. This legacy F-frame breaker mounts into standard Square D I-Line panelboards and switchboards using a plug-on connection. Rated for 65kAIC at 480VAC, it is an exact replacement for older installations and can be substituted with the HJA36040.

Specifications

Key specifications
Brand Square D
Part Number FJA34040
Series FJA
Amperage 40A
Poles 3
Mounting Style I-Line
Voltage 240VAC, 480Y/277VAC, 480VAC, 250VDC
Phase 3
AIC Rating 100kA @ 240VAC, 65kA @ 480Y/277VAC, 65kA @ 480VAC, 10kA @ 250VDC
Fit and installation
Frame Type FJA
Terminal Type Lugs
For Use With Square D I-Line Panelboards and Switchboards
Wire Gauge 14-1/0 AWG (Cu/Al)
Max Wire 1/0 AWG
Min Wire 14 AWG
Protection and operation
Trip Technology Thermal Magnetic
Trip Function Code LI
Trip Function Long-Time, Instantaneous
Trip Adjustability Fixed Thermal, Fixed Magnetic
Standards and features
Available Options Shunt Trip, Auxiliary Switch, Alarm Switch, Undervoltage Release
Accessories Load Side Lugs
Standards UL 489, CSA C22.2 No. 5, NEMA AB 1, IEC 60947-2
Approval CSA, HACR, UL
Temp Rating 40C
Construction Features HACR Rated, High Interrupting Capacity

Product FAQs

6 answers
What panelboards are compatible with the FJA34040 circuit breaker?

This breaker is designed for use in Square D I-Line panelboards and switchboards. It features an I-Line style plug-in connection that mounts directly onto the interior busbar stack.

What does the J in the FJA34040 catalog number indicate?

In the Square D F-frame nomenclature, the J designates the interrupting rating tier. For this breaker, it signifies a high interrupting capacity of 65kA at 480VAC and 100kA at 240VAC.

Is the Square D FJA34040 a current or legacy circuit breaker?

The FJA34040 is part of the legacy Square D F-frame molded case circuit breaker family. While still widely used for maintaining existing I-Line panelboards, it is often replaced by the newer PowerPact H-frame series, such as the HJA36040, in modern installations.

What wire sizes are accepted by the standard lugs on the FJA34040?

The standard lugs on this breaker accept wire sizes ranging from 14 AWG to 1/0 AWG. They are rated for use with either copper or aluminum conductors.

Does the FJA34040 have adjustable trip settings?

No, this breaker features a fixed thermal and fixed magnetic trip unit. It provides standard long-time and instantaneous protection without adjustable dials.

Can the FJA34040 be used in direct current applications?

Yes, this breaker is rated for use in DC systems up to 250VDC, where it provides an interrupting rating of 10kA.

SuperClub

Join free. Get 500 SuperPoints.

Earn points on eligible purchases and redeem them at checkout.

100 SuperPoints = $1 off.

Warranties

60-Day Warranty

Your purchase includes 60 days of SuperBreakers warranty coverage.

Get a Quote

Don’t see what you’re looking for?

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.

Read our full shipping policy

Same Day Shipping

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.