Square D KA36175-1021 Molded Case Circuit Breaker
- 175A
- 3 Pole
- I-Line
Quantity
Square D KA36175-1021 - 175A 3 Pole Molded Case Circuit Breaker
Re-Certified
Quantity
Description
Designed for advanced control, the Square D KA36175-1021 is a 175A, 3-pole molded case circuit breaker equipped with a 120-240VAC shunt trip. This integrated feature allows for remote tripping in emergency shutdown systems. It installs into Square D I-Line panelboards. As a legacy K-Frame component, it serves as a direct replacement for older installations, though new applications would use the JGA36175 with an added shunt trip accessory. It features a thermal-magnetic LI trip unit.Specifications
| Brand | Square D |
|---|---|
| Part Number | KA36175-1021-R |
| Series | KA |
| Amperage | 175A |
| Poles | 3 |
| Mounting Style | I-Line |
| Voltage | 240VAC, 480VAC, 600VAC, 250VDC |
| Phase | 3 |
| AIC Rating | 42kA @ 240VAC, 25kA @ 480VAC, 22kA @ 600VAC, 10kA @ 250VDC |
| Terminal Type | Lugs |
|---|---|
| For Use With | Square D I-Line Panelboards and Switchboards |
| Wire Gauge | 4 AWG - 350 kcmil (Al/Cu) |
| Max Wire | 350 kcmil |
| Min Wire | 4 AWG |
| Trip Technology | Thermal Magnetic |
|---|---|
| Trip Function Code | LI |
| Trip Function | Long-Time, Instantaneous |
| Trip Adjustability | Fixed Thermal, Adjustable Magnetic |
| Available Options | Auxiliary Switch, Undervoltage Release, Alarm Switch, Padlock Attachment |
|---|---|
| Accessories | Shunt Trip (120-240VAC), Load Side Lugs |
| Standards | CSA C22.2 No. 5, HACR, IEC 60947-2, NEMA AB 1, UL 489 |
| Approval | CSA, UL |
| Temp Rating | 40C |
| Construction Features | HACR Rated, Visual Trip Indicator, Non-Interchangeable Trip |
Product FAQs
8 answersWhat does the -1021 suffix indicate on the KA36175-1021?
The -1021 suffix denotes a factory-installed 120/240VAC shunt trip. This internal accessory allows the breaker to be tripped remotely via a control voltage signal, which is commonly required for emergency shutdown systems or fire alarm interlocks.
Is the KA36175-1021 still manufactured, or is there a modern replacement?
The Square D KA series is a legacy K-Frame breaker. For new installations, the modern equivalent is the PowerPact J-Frame series, such as the JGA36175, which requires a separate shunt trip accessory. However, this KA breaker remains an exact drop-in replacement for existing K-Frame slots in older panelboards.
Can I field-install a shunt trip into a standard KA36175 breaker?
No. For legacy Square D K-Frame breakers, internal accessories like shunt trips are factory-installed. If your application requires remote tripping capabilities, you must source a breaker with the -1021 suffix rather than attempting to retrofit a standard unit.
How does the I-Line mounting system work for this breaker?
The I-Line mounting style utilizes a plug-in jaw connection that engages directly with the panelboard bus stack. This design allows for faster installation compared to bolt-on breakers and eliminates the need for separate bus connections or cabling.
What does the LI trip function code mean for the KA36175-1021?
The LI designation indicates a thermal-magnetic trip unit providing Long-Time (L) and Instantaneous (I) protection. The thermal element offers fixed protection against sustained overloads, while the magnetic element provides adjustable protection against short circuits.
Why is this thermal-magnetic breaker suitable for 250VDC applications?
Unlike electronic trip units that require alternating current to power their microprocessors, thermal-magnetic trip units use bimetallic strips and electromagnets that respond directly to current flow. This allows the KA36175-1021 to effectively protect DC circuits up to 250VDC with a 10kA interrupting capacity.
What wire sizes are accepted by the standard lugs on this K-Frame breaker?
The factory lugs on the KA36175-1021 accept aluminum or copper conductors ranging from 4 AWG to 350 kcmil, providing flexibility for various conduit and wire sizing requirements in 175A circuits.
What type of panelboard is required for the KA36175-1021?
This breaker is designed exclusively for use in Square D I-Line panelboards and switchboards. It cannot be installed in standard load centers, NQ, or NF panelboards.
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Reviews
Review summary
Customers rate this product 4.9 out of 5 based on 14 reviews.
- RFRon F.Verified BuyerReviewingSquare D KA36150 - 150A 3 Pole Molded Case Circuit BreakerI recommend this productRated 5 out of 5 stars7/27/26Square D KA36150
As usual, on time and in great condition!
- SJShawn J.Verified BuyerReviewingSquare D KA36225 - 225A 3 Pole Molded Case Circuit BreakerI recommend this productRated 5 out of 5 stars4/27/26I Line BreKER
Found exactly what I was looking for. They called and set over specs so I could confirm the fit!
- RFRon F.Verified BuyerReviewingSquare D KA36100 - 100A 3 Pole Molded Case Circuit BreakerI recommend this productRated 5 out of 5 stars4/9/26Multiple orders
I have purchased multiple breakers (of fairly large size) from SuperBreakers and their pricing has been excellent and the delivery time spot on. I would highly recommend them
- MFMatt F.Verified BuyerReviewingSquare D KA36100 - 100A 3 Pole Molded Case Circuit BreakerI recommend this productRated 5 out of 5 stars8/21/25Order Messed Up - Breaker Great
I have ordered many breakers through SuperBreakers with no issues until this order. I ordered this breaker and it wasn't shipped. I sent a message and was told that a mistake was make in shipping and that they would next day air the breaker to me. 5 days later (weekend in there) the breaker arrived. Not next day air, but shit happens. Sent the breaker still in the box out with my electrician and received a call from him that the breaker that was sent was a KAL36100 not the KA36100. I reached out to SuperBreakers and was told the correct breaker would be next day aired that day and I was emailed a shipping label to send back the incorrect one. This time it arrived the next day and was installed. This error cost my customer a couple days with out power to a dimmer cabinet and about 2 extra hours of labor, but all was okay in the end. Mistakes happen. The help and quick responses to my emails I received from Mike David showed me enough about this company. I look forward to my next order. Thank you for working this situation out in timely manor.
- JHJoel H.Verified BuyerReviewingSquare D KA36200 - 200A 3 Pole Molded Case Circuit BreakerI recommend this productRated 5 out of 5 stars8/5/25Worked As Planned
They had what we needed to match existing equipment, they shipped the same day and we put it right into service, no problems from first phone call to delivery and install.