ABB / General Electric THJK436300 Molded Case Circuit Breaker
- 300A
- 3 Pole
- Unit Mount
Quantity
ABB / General Electric THJK436300 - 300A 3 Pole Molded Case Circuit Breaker
Re-Certified
Quantity
Description
Providing reliable overcurrent defense, the GE THJK436300 is a 3-pole, 300A unit mount MCCB designed for industrial environments. It features fixed thermal and adjustable magnetic trip settings to accommodate specific loads. The breaker fits into GE J600 enclosures, A-Series panelboards, and switchboards. Facilities upgrading legacy systems can replace this unit with an ABB Tmax XT5 using a retrofit kit.Specifications
| Brand | ABB / General Electric |
|---|---|
| Part Number | THJK436300-R |
| Series | THJK |
| Amperage | 300A |
| Poles | 3 |
| Mounting Style | Unit Mount |
| Voltage | 240VAC, 480VAC, 600VAC, 250VDC, 500VDC |
| Phase | 3 |
| AIC Rating | 65kA @ 240VAC, 35kA @ 480VAC, 25kA @ 600VAC, 40kA @ 250VDC, 20kA @ 500VDC |
| Terminal Type | Lugs |
|---|---|
| For Use With | GE J600 Enclosures, GE A-Series Panelboards, GE Switchboards, GE Motor Control Centers |
| Wire Gauge | (1) 6 AWG - 600 kcmil (Cu/Al) or (2) 2/0 AWG - 250 kcmil (Cu/Al) |
| Max Wire | 600 kcmil |
| Min Wire | 6 AWG |
| Trip Technology | Thermal Magnetic |
|---|---|
| Trip Function Code | LI |
| Trip Function | Long-Time, Instantaneous |
| Trip Adjustability | Fixed Thermal, Adjustable Magnetic |
| Available Options | Shunt Trip, Auxiliary Switch, Undervoltage Release, Alarm Switch, Line Side Lugs |
|---|---|
| Accessories | Load Side Lugs Included (TCAL43) |
| Standards | CSA C22.2 No. 5, NEMA AB-1, UL 489 |
| Approval | CSA, UL |
| Temp Rating | 40C |
| Construction Features | High Interrupting Capacity, Interchangeable Trip Unit, Reverse Feed, Trip-Free Mechanism |
Product FAQs
7 answersWhat enclosures and panelboards are compatible with the THJK436300?
This J-Frame breaker is designed for integration into GE J600 enclosures, GE A-Series panelboards, GE switchboards, and GE motor control centers. It is commonly used to support 300A distribution in legacy GE infrastructure.
What wire sizes and configurations are accepted by the lugs on the THJK436300?
The standard lugs support dual-wire configurations. You can terminate either a single 6 AWG to 600 kcmil conductor or two 2/0 AWG to 250 kcmil conductors per phase. Both copper and aluminum wires are accepted.
Can the THJK436300 be used in DC voltage applications?
Yes, this breaker is rated for DC systems in addition to standard AC voltages. It provides an interrupting capacity of 40kAIC at 250VDC and 20kAIC at 500VDC, making it suitable for specific industrial DC distribution.
How does the adjustable magnetic trip work on the THJK436300?
While the thermal overload protection is fixed at 300A, the magnetic trip is adjustable. This allows electricians to tune the instantaneous short-circuit response to coordinate with downstream breakers or to ride through motor inrush currents without nuisance tripping.
What does the LI trip function code indicate on this breaker?
The LI designation means the trip unit provides Long-Time (L) and Instantaneous (I) protection. The Long-Time function prevents damage from sustained overloads, while the Instantaneous function clears high-fault short circuits immediately.
How does the THJK436300 mount into a panelboard?
This is a unit-mount, bolt-on circuit breaker. It requires bolted connections directly to the bus or mounting pan in compatible GE switchboards and panelboards, ensuring a secure, high-amperage connection.
Is the THJK436300 a direct replacement for older GE J-Frame breakers?
Yes, it is a direct replacement for legacy 300A, 3-pole GE J600 frame breakers with matching interrupting ratings. Since ABB acquired GE Industrial Solutions, these legacy frames have transitioned to limited production, making them essential for maintaining existing GE A-Series panels without requiring full retrofits.
SuperClub
Join free. Get 500 SuperPoints.
Earn points on eligible purchases and redeem them at checkout.
100 SuperPoints = $1 off.
Warranties
Add an extra year of protection
60-Day Warranty
Your purchase includes 60 days of SuperBreakers warranty coverage.
Add a 1-year warranty extension in your cart.
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.
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.