Square D FJA140505 Molded Case Circuit Breaker
- 50A
- 1 Pole
- I-Line
Quantity
Square D FJA140505 - 50A 1 Pole Molded Case Circuit Breaker
New
Quantity
Description
Part of the legacy F-Frame series, this 50-amp, single-pole molded case circuit breaker provides robust long-time and instantaneous trip functions for commercial environments. The unit mounts into Square D I-Line panelboards utilizing a factory-configured Phase C connection. Note that this model is replaced by the HJA260505, which requires two pole spaces. Rated for 65kA interrupting capacity at 277VAC, it ensures high-level fault clearance and carries an HACR rating.Specifications
| Brand | Square D |
|---|---|
| Part Number | FJA140505 |
| Series | FJA |
| Amperage | 50A |
| 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 |
|---|---|
| Accessories | Load Side Lugs Included, 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
6 answersWhat panelboards are compatible with the FJA140505?
This breaker is designed exclusively for Square D I-Line panelboards and switchboards. It features an I-Line style plug-in connection and will not fit in standard NQ, NF, or QO load centers.
How does the FJA140505 mount into the panel?
It utilizes an I-Line plug-in mounting system with integrated blow-on jaw connectors. The breaker jaws press directly onto the panel busbar stack and are secured by ratcheting a captive mounting bracket screw into the pan. This eliminates the need for separate mounting kits or cable connections to the bus.
What does the 5 at the end of the FJA140505 catalog number signify?
In Square D I-Line nomenclature, the final digit indicates the factory-configured phase connection. The 5 means this 1-pole breaker is built specifically to connect to Phase C on the panel bus.
Can I use this 1-pole breaker on a 480V ungrounded delta system?
No. The 480Y/277VAC rating means it is only approved for solidly grounded wye systems where the voltage to ground does not exceed 277V. It cannot be used on 480V delta or ungrounded systems.
What do the letters FJA mean in the part number?
The letter F designates the legacy F-Frame family, J indicates the high interrupting rating of 65kAIC at 277V, and A specifies the I-Line plug-in mounting style.
Does this breaker provide ground fault or arc fault protection?
No. The FJA140505 is a standard thermal-magnetic breaker providing only long-time overload and instantaneous short-circuit protection. It does not include GFCI or AFCI circuitry.
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