ZINSCO QB24-100N U 100A 2P 240V Molded Case Circuit Breaker QB24100N

Description:

The Zinsco QB24-100N U is a 2-pole 100 Amp molded case circuit breaker designed for use in Zinsco / GTE Sylvania panelboards. It operates at 240 VAC and features a thermal-magnetic trip mechanism that protects circuits from overloads and short circuits. This model belongs to the QB24 series and uses a bolt-on mounting design, ensuring a secure electrical and mechanical connection to the panel bus.

Applications:

This breaker is commonly used in residential and commercial distribution systems as a main or feeder breaker for subpanels, large appliances, HVAC units, and other high-load equipment requiring 100A protection. It is typically installed in older Zinsco bolt-on panelboards and is now considered obsolete, often replaced with modern equivalents for improved safety and reliability.

Technical Specifications:

• Manufacturer: Zinsco / GTE Sylvania
• Model / Part Number: QB24-100N / QB2100 equivalent
• Product Type: Molded Case Circuit Breaker (Bolt-On)
• Poles: 2-Pole
• Current Rating: 100 Amps
• Voltage Rating: 240 VAC
• Phase: Single-phase
• Interrupt Rating: ~10 kAIC @ 240V
• Trip Type: Thermal-magnetic (LI – long-time & instantaneous)
• Mounting: Bolt-on (QB series)
• Function: Overcurrent and short circuit protection
• Status: Discontinued / obsolete

Common Replacements:

• Square D QOB2100 2-Pole 100A Bolt-On Circuit Breaker
• Siemens Q2100 / BQD2100 2-Pole 100A Circuit Breaker
• Eaton BAB2100H 2-Pole 100A Bolt-On Breaker