Description
🌐 Product Overview
The Terasaki TL-800F is a heavy-duty, high-capacity molded case circuit breaker (MCCB) engineered for the protection of low-voltage electrical distribution networks and industrial power systems. With a nominal current rating optimized at 700A, this circuit breaker delivers superior overcurrent, short-circuit, and thermal overload protection. It is widely recognized for its robust breaking capacity, arc-extinguishing reliability, and stable performance within demanding motor control centers and main distribution switchboards.
⚙️ Technical Specifications
- Series: TemBreak Series / Heavy Industrial MCCB Line
- Dimensions: 410mm x 210mm x 145mm
- Weight: 11.50 kg
- Origin: Japan
- Rated Current (In): 700A
- Number of Poles: 3 Poles (3P)
- Rated Operational Voltage (Ue): 690V AC
- Rated Insulation Voltage (Ui): 800V AC
- Trip Unit Type: Adjustable Thermal-Magnetic or Electronic Trip Unit
🚀 Application Fields
- Main Switchboards: Serves as the primary incoming or outgoing feeder protection unit in low-voltage main distribution boards (MV/LV substations).
- Marine Power Systems: Installed in shipboard electrical grids to provide reliable short-circuit protection under heavy vibrational conditions.
- Heavy Manufacturing Plants: Protects large industrial motor control panels, busbar systems, and power-hungry production machinery.
- Data Centers & Infrastructure: High-amperage backup power distribution and automatic transfer switch (ATS) coupling systems.
📖 Product Instructions
- Mounting: Position and bolt the breaker onto a clean, flat mounting plate within the switchgear cabinet. Maintain specified clearances to metallic walls to safely dissipate arc gases.
- Cable Termination: Secure copper or aluminum busbars/cables to the front-connection terminal extensions using high-tensile bolts. Apply the recommended manufacturer torque setting to prevent local overheating.
- Adjustment: Set the adjustable thermal (overload) and magnetic (short-circuit) pick-up dials on the front face of the trip unit to match the calculated protection coordination curves of the facility.
✅ Initial Startup Checklist
- Verify the breaker’s rated current (700A) matches the circuit load profile and cable carrying capacity.
- Check that all line-side and load-side terminal connections are securely tightened to specification.
- Confirm the phase barriers are installed correctly between the terminal poles to prevent phase-to-phase flashover.
- Manually cycle the breaker handle through “ON”, “OFF”, and “TRIP” (via the push-to-trip button) to ensure smooth mechanical operation before energizing.
🛠️ Maintenance & Care
- Terminal Torque Audits: Conduct an annual thermal inspection (infrared thermography) and re-torque connections to eliminate contact resistance.
- Mechanism Lubrication: Cycle the breaker mechanically 3-5 times during scheduled shutdown periods to prevent the internal latching linkages from seizing.
- Enclosure Cleaning: Clean the molded resin casing with a dry lint-free cloth to remove carbon deposits and ambient dust, which can form conductive tracking paths.
⚠️ Safety Precautions
- De-energization: Never perform installation, adjustment, or maintenance on the circuit breaker while line-side voltage is active. Use proper lockout/tagout (LOTO) protocols.
- Arc Exhaust Clearance: Keep the ventilation exhaust vents at the top of the breaker clear from obstruction to ensure safe pressure relief during fault interruption.
- Weight Warning: Utilize proper lifting techniques or mechanical assists when positioning the 11.50 kg unit into deep switchgear compartments.
🔍 Troubleshooting & FAQ
- Q: The breaker handle rests in the middle position and will not reset to the “ON” position. What is wrong?
- A: The middle position indicates a tripped state. To re-engage the contacts, you must first push the handle firmly down past the “OFF” position until it clicks (resetting the internal mechanism), then throw it upward to “ON”.
- Q: The unit trips immediately upon attempting to close the breaker handle. What does this imply?
- A: This indicates a persistent high-level short circuit or severe grounding fault downstream. Do not force the handle closed; isolate the downstream load and check for shorted phases or catastrophic insulation breakdown before re-testing.
- Q: Can the thermal trip threshold be modified while the breaker is carrying a load?
- A: It is highly advised to adjust the dials only when the system is isolated or running completely offline to avoid safety hazards or accidental trips caused by physical dial movement.
