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Square D QOB330 three-pole bolt-on breaker with paddle actuator

SQUARE D

SQUARE D QOB330 30A 3 Pole 120/240V AC circuit breaker

SKU CH-JKA9-CQ0MA

Three-pole miniature breaker rated 30 A at 120/240 V AC with 10 kA interrupting capacity, bolt-on mounting for QO load centres

  • 30 A protection for three-phase loads
  • 10 kA interrupting rating handles fault current
  • Bolt-on mounting fits QO panelboards
  • 48 V DC rating adds application flexibility
  • Pressure-plate terminals simplify wire connections

Three-pole 30 A circuit protection

The SQUARE D QOB330 is a bolt-on miniature circuit breaker rated at 30 A and 120/240 V AC for three-phase panels. It fits QO-series load centres and NQOD panelboards using a pressure-plate terminal connection.

Thermal behaviour in normal operation

The breaker carries its rated current continuously at the listed minimum operating temperature of 77 Degrees F. Its standard thermal-magnetic trip curve protects conductors without nuisance tripping during everyday load fluctuations.

Sustained overload response

Under prolonged overcurrent the thermal element trips to protect wiring, while the magnetic element provides a 10 kA interrupting rating at 120/240 V AC for short-circuit events. The 48 V DC rating does not extend AC fault-current performance.

How it compares

Measured against everything we stock in Breakers & Circuit Protection, at today’s prices. Recalculated every night.

Price $208.99
Pricier than about 82% of the 1,135 comparable items (median $54.99).

Specifications

Product
Brand nameSQUARE D

Questions about this item

How do I bolt the QOB330 into a QO load center and what step is often missed?

Align the bolt-on base with the panel bus, tighten the mounting screws to the specified torque, then press the paddle actuator until it latches — many installers forget to verify the pressure-plate terminals are fully seated on the conductors.

What maintenance or replacement will the 30 A three-pole breaker need over time?

Periodically check the bolt-on mounting hardware and pressure-plate terminal torque; if the paddle actuator becomes stiff or the 10 kA interrupting rating is exceeded during a fault, replace the breaker.

What is the first limit reached when the QOB330 runs continuously at full load?

The 30 A thermal trip curve opens the contacts before the 77 °F minimum operating temperature or the 10 kA interrupting capacity becomes a factor.

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