ZINSCO QFL3125 U 125A 240V 3-pole Molded Case Circuit Breaker

Description:

The Zinsco QFL3125 U is a 125 Amp, 3-pole molded case circuit breaker designed for use in Zinsco / GTE Sylvania panelboards. It operates on 240V three-phase systems and features a thermal-magnetic trip mechanism that provides protection against overloads and short circuits. It belongs to the QFL series and is typically configured as a bolt-on or fixed-mounted breaker, ensuring a secure connection to the panel bus. Standard specifications for comparable QFL/QFB series breakers confirm a 125A rating, 3 poles, and 240V operation with an approximate interrupt rating of 10 kAIC.

Applications:

The Zinsco QFL3125 breaker is commonly used in commercial and industrial electrical systems requiring 125A three-phase protection, such as distribution panels, feeder circuits, motor control centers, and heavy-duty machinery. It is specifically intended for legacy Zinsco panelboards and is primarily used today for maintenance or replacement of existing installations rather than new installations.

Technical Specifications:

• Manufacturer: Zinsco / GTE Sylvania
• Model / Part Number: QFL3125 U
• Product Type: Molded Case Circuit Breaker
• Poles: 3-Pole
• Current Rating: 125 Amps
• Voltage Rating: 240 VAC
• Phase: 3-phase
• Mounting: Bolt-on / fixed mount (QFL series typical)
• Trip Type: Thermal-magnetic
• Interrupt Rating: ~10 kAIC @ 240V
• Function: Overcurrent and short circuit protection
• Status: Obsolete / discontinued

Common Replacements:

• Square D QOB3125 3-Pole 125A Bolt-On Circuit Breaker
• Siemens BQD3125 3-Pole 125A Bolt-On Breaker
• Eaton BAB3125H 3-Pole 125A Bolt-On Breaker