[Lifetime Warranty] 40 Amp DC Miniature Circuit Breaker 120V/240V
40 Amp DC miniature circuit breaker with 1-pole thermal magnetic trip and retail packaging.
Internal view and exterior of 40 Amp DC miniature circuit breaker for 120V/240V systems.
Single-pole 40 Amp DC miniature circuit breaker with 120V/240V rating and red toggle switch.
40 Amp DC miniature circuit breaker with red switch and overload protection features.
Collage showing a 40 Amp DC miniature circuit breaker installed in an electrical panel with solar and lighting systems.
40 Amp DC miniature circuit breaker showing temperature resistance range from -13°F to 140°F.
Technician installing a 40 Amp DC miniature circuit breaker in an electrical panel.
40 Amp DC miniature circuit breaker with 1-pole thermal magnetic trip and retail packaging.
Internal view and exterior of 40 Amp DC miniature circuit breaker for 120V/240V systems.
Single-pole 40 Amp DC miniature circuit breaker with 120V/240V rating and red toggle switch.
40 Amp DC miniature circuit breaker with red switch and overload protection features.
Collage showing a 40 Amp DC miniature circuit breaker installed in an electrical panel with solar and lighting systems.
40 Amp DC miniature circuit breaker showing temperature resistance range from -13°F to 140°F.
Technician installing a 40 Amp DC miniature circuit breaker in an electrical panel.
Lifetime Warranty

[Lifetime Warranty] 40 Amp DC Miniature Circuit Breaker 120V/240V

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40 Amp DC Miniature Circuit Breaker 120V/240V

Key Features

  • Current Rating: 40 Amps
  • Voltage Rating: 120V/240V DC
  • Poles: 1
  • Interrupting Capacity: 10 kA
  • Protection Type: Thermal-magnetic overload and short-circuit protection
  • Mounting Style: Standard 35mm DIN rail
  • Actuator: Trip-free toggle mechanism with clear on/off status indicator

Replaces / Cross-Reference Part Numbers

  • SRDZ47-63Z
  • Note: This is a DC-rated circuit breaker. Verify all electrical specifications before substituting for other models.

Compatibility & Fitment

  • Application: Designed for DC circuits such as solar photovoltaic (PV) systems, battery energy storage, and other DC power distribution applications.
  • Enclosure Fitment: Mounts on standard 35mm DIN rails inside compatible breaker panels, enclosures, and combiner boxes.
  • Wire Compatibility: Accepts wire gauges appropriate for 40A circuits per local electrical codes.

When to Replace

  • Fails to trip during a known overcurrent or short-circuit event.
  • Trips repeatedly under normal load conditions.
  • Will not reset after being tripped and the fault is cleared.
  • Exhibits physical damage, including cracks, chips, or signs of burning/melting.
  • The housing feels excessively hot during standard operation.

Installation Tips

  • Disconnect and lock out all power sources before beginning installation.
  • Verify breaker ratings match the specific requirements of the DC circuit.
  • Mount securely onto the DIN rail, ensuring a firm connection.
  • Connect line and load side wiring using the correct wire gauge.
  • Tighten terminal screws to the manufacturer-specified torque to prevent poor connections and overheating.
  • After installation, restore power and verify proper circuit operation.
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  • Swift Reaction

    Swift Reaction

    With fast magnetic arc extinguishing , the miniature circuit breaker reacts to overload & short circuits extremely fast
  • Robust Plastic Shell

    Robust Plastic Shell

    Flame retardant material makes the product sturdy and durable
  • Cold & Heat Resistant

    Cold & Heat Resistant

    This product adopts operating ambient temperatures from -13°F to 140°F that can withstand harsh conditions & resistant to cold and heat
  • Easy To Install

    Easy To Install

    The installation just takes a few minutes and will save you at least a hundred bucks in labor
PRECISION PROTECTION FOR EVERY CONNECTION

PRECISION PROTECTION FOR EVERY CONNECTION

Brand Model Number
Product pole number 1P
Rated current 40A
Rated voltage 120V/240V
Operating ambient temperature -13°F(-25℃) ~ 140°F(60℃)

FAQ

This 40 Amp, 2-pole miniature circuit breaker is designed to be compatible with various industry-standard load centers. It serves as a direct replacement for models including QO240, QOU240, QOB2401021, and HOM240.
This is a 2-pole thermal magnetic circuit breaker rated for 40 Amps. It is designed for 120/240V systems and features an interrupting rating of 10 kilo-Amps (10kA). It is also HACR rated, making it suitable for use with heating, air conditioning, and refrigeration equipment.
You likely need a replacement if the breaker trips immediately upon being reset, fails to stay in the 'on' position, or shows visible signs of damage such as scorching, melting, or a persistent burning smell. Additionally, if the breaker feels loose when plugged into the panel or fails to provide power to the circuit despite being in the 'on' position, it should be tested and replaced.
Installation is straightforward for those familiar with electrical panels, but it requires extreme caution. You must turn off the main power to the load center before beginning. The process involves snapping the breaker into the bus bar and securing the wires into the lug terminals. If you are not comfortable working with electrical panels, it is recommended to hire a licensed electrician to ensure the connections are torqued to the correct specifications.
Before installing, inspect the bus bar in your panel for any signs of pitting, corrosion, or heat damage. Ensure that the wire gauge being used is appropriate for a 40 Amp load. If the existing wire is damaged or undersized, replacing the breaker alone will not resolve the underlying issue and may create a fire hazard.