Square D FJA140405 Molded Case Circuit Breaker
- 40A
- 1 Pole
- I-Line
Quantity
Square D FJA140405 - 40A 1 Pole Molded Case Circuit Breaker
New
Quantity
Description
Built for heavy-duty electrical systems, the FJA140405 provides reliable thermal-magnetic protection with long-time and instantaneous (LI) trip functions. This 40A, 1-pole breaker installs into Square D I-Line panelboards and features a factory-configured Phase C connection. With a high interrupting capacity of 65 kAIC at 277VAC, it ensures robust performance in demanding environments. For future upgrades, this legacy unit is replaced by the HJA260405, which occupies two pole spaces.Specifications
| Brand | Square D |
|---|---|
| Part Number | FJA140405 |
| Series | FJA |
| Amperage | 40A |
| Poles | 1 |
| Mounting Style | I-Line |
| Voltage | 240VAC, 277VAC, 125VDC |
| Phase | 1 |
| AIC Rating | 65kA @ 240VAC, 65kA @ 277VAC, 10kA @ 125VDC |
| 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 |
| Trip Technology | Thermal Magnetic |
|---|---|
| Trip Function Code | LI |
| Trip Function | Long-Time, Instantaneous |
| Trip Adjustability | Fixed Thermal, Fixed Magnetic |
| Available Options | Shunt Trip, Auxiliary Switch, Alarm Switch, Undervoltage Release, Padlock Attachment |
|---|---|
| Accessories | Phase C Connection (Factory Configured) |
| 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
7 answersWhich panelboards accept the FJA140405 circuit breaker?
This breaker is engineered specifically for Square D I-Line panelboards and switchboards. It utilizes an I-Line style plug-in connection to mount directly to the bus stack.
What type of protection does the LI trip function provide?
The LI designation indicates a thermal magnetic trip unit. It provides Long-Time (L) thermal protection for sustained overloads and Instantaneous (I) magnetic protection for immediate short circuit clearing.
Are the trip settings on the FJA140405 adjustable?
No, this breaker features fixed thermal and fixed magnetic trip settings. The trip points cannot be adjusted in the field.
What are the acceptable wire sizes for the FJA140405 terminals?
The factory lugs accommodate wire sizes from 14 AWG up to 1/0 AWG. The terminals are rated for both copper and aluminum (Cu/Al) conductors.
Is this breaker suitable for direct current (DC) systems?
Yes, the FJA140405 is rated for use in DC applications up to 125VDC, where it provides an interrupting rating of 10kAIC.
Does the I-Line plug-in connection require additional mounting hardware?
No, the I-Line style plug-in design allows the breaker to attach directly to the panelboard bus assembly. The jaws engage the bus bars securely without requiring separate mounting brackets or cable connections.
Is the FJA140405 part of a legacy product line?
Yes, this breaker belongs to the legacy Square D F-frame family of molded case circuit breakers. It serves as a direct replacement for existing F-frame installations in I-Line switchboards.
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