Zinsco QCB QCB270 2 Pole 70 Amp 240V Circuit Breaker

Description:

The Zinsco QCB270 is a 70 Amp, 2-pole molded case circuit breaker designed for use in Zinsco / GTE Sylvania panelboards. It operates on 120/240V systems and features a thermal-magnetic trip mechanism that protects circuits from overloads and short circuits. It belongs to the QCB series and is typically a bolt-on type breaker, providing a secure mechanical and electrical connection to the panel bus. Product listings confirm its configuration as 70A, 2-pole, 240V with bolt-on mounting.

Applications:

The Zinsco QCB270 breaker is commonly used in residential and light commercial electrical systems for 240V circuits requiring 70A protection, such as HVAC systems, subpanels, compressors, and heavy-duty equipment loads. It is specifically intended for legacy Zinsco bolt-on panels and is primarily used today for maintenance or replacement of existing installations.

Technical Specifications:

• Manufacturer: Zinsco / GTE Sylvania / Challenger
• Model / Part Number: QCB270
• Product Type: Molded Case Circuit Breaker (Bolt-On)
• Poles: 2-Pole
• Current Rating: 70 Amps
• Voltage Rating: 120/240 VAC
• Mounting: Bolt-on (QCB series)
• Trip Type: Thermal-magnetic
• Interrupt Rating: ~10 kAIC @ 240V (typical class)
• Phase: Single-phase
• Function: Overcurrent and short circuit protection
• Status: Obsolete / discontinued

Common Replacements:

• Connecticut Electric UBIZ270B 2-Pole 70A Zinsco Replacement Breaker
• Siemens Q270 2-Pole 70A Circuit Breaker
• Square D QOB270 2-Pole 70A Bolt-On Circuit Breaker