Key Technical Specifications
- Product Model: TB43300
- Manufacturer: General Electric (GE)
- Product Type: Molded Case Circuit Breaker
- Amperage Rating: 300 Amp
- Number of Poles: 3
- Voltage Rating: 600 Volt
- Breaker Frame Type: TB4
- Mounting Style: Bolt-on (Verify with panel specs)
- Interrupting Rating: Verify specific AIC rating based on application
- Application: Industrial power distribution and motor protection
Product Introduction
The GE TB43300 is a 3-pole, 300-amp molded case circuit breaker designed for 600-volt industrial power distribution systems. It serves as a critical protective device in motor control centers, switchboards, and panelboards, safeguarding electrical circuits against overloads and short circuits.Built on GE’s reliable TB4 frame platform, the TB43300 provides robust mechanical and electrical performance in demanding industrial environments. This breaker is commonly specified for heavy machinery feeds, main feeder protection, and large motor branch circuits where dependable fault interruption is mandatory.
Installation & Configuration Guide
Preparation (10 min)
- Verify the TB43300 amperage and voltage ratings match the panel schedule.
- Confirm bolt-on mounting hardware is available and torqued to spec.
- Wear appropriate PPE and follow arc flash safety protocols. (Lockout/tagout is non-negotiable at 600V.)
Removal (5–10 min)
- De-energize the panel and verify zero energy with a calibrated meter.
- Disconnect line and load conductors from the breaker terminals.
- Remove the mounting bolts and carefully extract the breaker from the panel.
Installation (10 min)
- Position the TB43300 in the panel and secure with mounting bolts.
- Torque all terminal connections to GE’s specified values (typically 25-30 in-lbs for this frame size — verify with manual).
- Reconnect line and load conductors, ensuring proper phase rotation.
Power-On & Test (10 min)
- Perform insulation resistance test (megger) before energizing.
- Energize the panel and verify voltage at the breaker terminals.
- Test the breaker’s trip mechanism using a secondary injection test set if available.
Troubleshooting Quick Reference
| Symptom | Probable Cause | Action |
|---|---|---|
| Breaker won’t close | Mechanism tripped or damaged | Reset breaker fully; inspect for mechanical damage |
| Immediate trip on close | Downstream fault or wrong rating | Megger test load side; verify 300A rating is correct |
| Overheating at terminals | Loose connections or corrosion | Re-torque terminals; inspect for pitting or discoloration |
| Nuisance tripping | Overload or worn trip unit | Monitor load current; test trip unit calibration |
| Physical damage | Age or previous fault event | Inspect arc chute and contacts; replace if compromised |
Dimensions, Mounting & Wiring Notes
- Frame Size: TB4 (Standard GE molded case frame)
- Mounting: Bolt-on to panel backplane
- Terminal Type: Line and load lug terminals (verify lug size for 300A conductors)
- Wiring Note: Use copper or aluminum conductors rated for 75°C or 90°C; torque all connections to manufacturer spec
FAQ
Can I use this breaker in a Siemens or Square D panel?
No. The TB43300 is designed for GE panelboards and bus structures. Cross-brand breaker compatibility is rare and typically violates UL listings. Always match the breaker to the panel manufacturer.Is this a thermal-magnetic or electronic trip breaker?
The TB43300 is typically a thermal-magnetic breaker in the TB4 frame. However, verify the specific trip unit designation on the breaker label, as some TB4 frames support interchangeable trip units.What does “RE-Certified” mean for this product?
RE-Certified means the breaker has been previously energized and undergone a detailed 12-point quality inspection and testing process to verify electrical, mechanical, and electromechanical function. It includes a 1-year warranty.I need to replace a TB43300AF14F, will this work?
The base model TB43300 covers the 300A/3P/600V specification. Suffixes like AF14F often indicate specific accessories, trip curves, or UL listings. Verify the suffix requirements with your panel documentation or contact us for cross-reference.Do you offer NETA testing on this breaker?
Yes. We can provide NETA-compliant testing performed by accredited technicians. This includes contact resistance, insulation resistance, and primary injection testing. NETA testing fees vary by product.What’s the interrupting rating for this breaker?
The interrupting capacity varies by specific catalog number and application. Check the breaker label for the exact AIC rating (e.g., 25kA, 35kA, 65kA at 600V). Never install a breaker with an AIC rating below the available fault current.How long is the warranty?
RE-Certified breakers carry a full 1-year no-hassle warranty. RE-Certified Plus units include NETA testing and a 2-year warranty with 100% money-back guarantee.
