Part of the QP series, the Siemens Q340 provides 40A, 3-pole circuit protection for commercial and industrial applications. It utilizes thermal-magnetic technology to safely interrupt overloads. This plug-on breaker installs into compatible Siemens load centers and panelboards. It serves as a seamless replacement for discontinued MP340 breakers, making it ideal for system maintenance. Rated for 10kAIC at 240VAC, the unit features a common trip mechanism and is HACR rated.
Which load centers accept the Siemens Q340 circuit breaker?
The Q340 Type QP breaker is designed for use in Siemens 3-phase PL, PN, SN, and ES series load centers, as well as compatible Siemens commercial panelboards.
Can the Q340 be used to replace legacy Murray or ITE breakers?
Yes. Siemens has officially designated Type QP breakers as the UL listed replacements for discontinued Murray Type MP breakers. The Q340 directly replaces the legacy Murray MP340 and original ITE Q340.
How much panel space is required to install the Q340?
As a 3-pole breaker with a standard 1-inch width per pole, the Q340 requires three adjacent full-size spaces in a 3-phase panelboard.
What are the catalog numbers for the higher interrupting rating versions of the Q340?
The standard Q340 has a 10kAIC rating. For systems with higher available fault current requirements, use the Q340H (Type QPH) for 22kAIC or the Q340HH (Type HQP) for 65kAIC at 240VAC.
Is the Siemens Q340 HACR rated?
Yes, this breaker is HACR rated, meaning it is approved for use with heating, air conditioning, and refrigeration equipment that requires certified group motor protection.
Can a 3-pole Q340 be installed in a standard single-phase residential load center?
No. Three-pole circuit breakers require a 3-phase load center or commercial panelboard to properly align with and connect to three distinct internal bus bars.
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Reviews
Review summary
Customers rate this product 5.0 out of 5 based on 47 reviews.
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Reviews Summary
Generated by AI from 91 most recent customer reviews
Last updated 8/1/25
Customers say these circuit breakers arrive quickly and match their specifications perfectly. Many reviews mention success finding hard-to-locate specialty breakers through this supplier. Common feedback includes praise for the accurate product descriptions, reliable shipping, and competitive pricing. While some note occasional stock limitations, users consistently report the breakers fit and function as intended.