GTE Sylvania QB2420A Molded Case Circuit Breaker

Description:

The Zinsco QB2420-A is a 20 Amp, 2-pole molded case circuit breaker designed for use in Zinsco / GTE Sylvania panelboards. It operates on 240V systems and features a thermal-magnetic trip mechanism that protects circuits from overloads and short circuits. This breaker belongs to the QB24 series and uses a bolt-on mounting design, ensuring a secure connection to the panel bus. It is often labeled as a “Zinsco-type” breaker and is considered rare due to limited availability in the surplus market.

Applications:

The Zinsco QB2420-A breaker is commonly used in residential and light commercial electrical systems for 240V branch circuits such as small HVAC units, water heaters, and dedicated appliance loads requiring 20A protection. It is installed in Zinsco bolt-on panels typically found in older electrical systems and is mainly used today for maintenance or replacement of existing equipment rather than new installations.

Technical Specifications:

• Manufacturer: Zinsco / GTE Sylvania
• Model / Part Number: QB2420-A
• Product Type: Molded Case Circuit Breaker (Bolt-On)
• Poles: 2-Pole
• Current Rating: 20 Amps
• Voltage Rating: 240 VAC
• Mounting: Bolt-on (QB series)
• Interrupt Rating: ~10 kAIC @ 240V
• Trip Type: Thermal-magnetic (LI)
• Phase: Single-phase
• Status: Discontinued / obsolete

Common Replacements:

• Square D QOB220 2-Pole 20A Bolt-On Circuit Breaker
• Siemens BQD220 2-Pole 20A Bolt-On Breaker
• Eaton BAB2020H 2-Pole 20A Bolt-On Breaker