ZINSCO HQB243040 50AMP 240V 3 POLE BOLT-ON (CHALLENGER SYLVANIA)

Description:

The Zinsco / Challenger / GTE Sylvania HQB243040 is a 3-pole 40 Amp bolt-on molded case circuit breaker used in industrial and commercial electrical distribution systems. It provides overcurrent protection for 240V three-phase circuits and is typically installed in Zinsco bolt-on panelboards and switchgear. This breaker is commonly used for protecting motors, machinery, and feeder circuits in legacy systems.

Applications:

The Zinsco HQB243040 breaker is widely used in industrial panels, motor control centers, and three-phase distribution systems where moderate load protection is required. It functions as a branch or feeder breaker for equipment such as pumps, compressors, and small industrial machines. It is part of the Zinsco HQB/QB series, which is now obsolete and discontinued but still found in older installations.

Technical Specifications:

• Manufacturer: Zinsco / GTE Sylvania / Challenger
• Model / Part Number: HQB243040 / QB243040
• Product Type: Molded Case Circuit Breaker (Bolt-On)
• Poles: 3-Pole
• Current Rating: 40 Amps
• Voltage Rating: 240 VAC
• Phase: 3-phase
• Interrupt Rating: ~10 kAIC @ 240V
• Trip Type: Thermal-magnetic (LI – long-time & instantaneous)
• Mounting: Bolt-on
• Function: Overcurrent and short circuit protection
• Status: Discontinued / obsolete

Common Replacements:

• Square D QOB340 3‑Pole 40A Bolt‑On Breaker
• Schneider Electric Multi9 3‑Pole 40A Breaker
• Generic 40A 3‑Pole Industrial Circuit Breaker