SIEMENS
SIEMENS BQ3B040 circuit breaker 40 A 240 V AC 3-pole bolt-on
Three-pole bolt-on breaker rated 40 A at 240 V AC with 10 kA interrupting capacity for Siemens panelboards
- 40 A three-pole protection for 240 V AC circuits
- 10 kA interrupting rating handles high fault currents
- Bolt-on mounting fits Siemens panelboards directly
- Lug terminals accept 8 AWG to 4 AWG aluminium or 6 AWG copper
- Operates up to 104 °F in a 125 A frame
Purpose and fit
The Siemens BQ3B040 is a three-pole miniature circuit breaker rated at 40 amps and 240 volts AC. It is designed for bolt-on installation in compatible Siemens panelboards and protects three-phase circuits in residential or light commercial settings.
Capacity and limits
The breaker carries a maximum AIR rating of 10 kA at 240 volts AC and fits a 125 amp frame size. It accepts copper wire from 8 AWG to 6 AWG and aluminium wire from 8 AWG to 4 AWG. Operation is rated up to 104 degrees Fahrenheit and it has no DC voltage rating.
Mounting and accessories
The unit uses a bolt-on mounting style with lug terminals for secure panelboard connection. No additional accessories or software are included in the package. The toggle actuator provides manual switching and trip indication.
Highlights
- 40 A three-pole protection for 240 V AC circuits
- 10 kA interrupting rating handles high fault currents
- Bolt-on mounting fits Siemens panelboards directly
- Lug terminals accept 8 AWG to 4 AWG aluminium or 6 AWG copper
- Operates up to 104 °F in a 125 A frame
Specifications
| Brand | Siemens |
|---|---|
| Model | BQ3B040 |
Questions about this item
Will the BQ3B040 bolt-on breaker fit alongside older Siemens BQ-series breakers in the same panelboard?
Yes, the BQ3B040 uses the same bolt-on mounting style and BQ frame size 125A, so it installs directly into compatible Siemens panelboards that accept BQ-series breakers.
How can I verify the 40 A, 240 V AC, 3-pole breaker is operating correctly after installation?
Switch the toggle actuator to the on position and confirm the circuit carries load without tripping; the breaker should remain latched up to its 10 kA interrupting rating at 240 V AC.
Does the BQ3B040 come with terminal lugs, or must I purchase wire connectors separately?
The breaker includes a terminal connection lug that accepts 8 AWG to 4 AWG aluminium or 6 AWG copper wire, so no separate lugs are required for conductors within that range.
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