The Q24020 is a Type QT quadplex miniature circuit breaker from Siemens, delivering 40A and 20A protection in a space-saving plug-on design. Built for residential applications, it allows installers to add multiple circuits without requiring a larger enclosure. Mounts into compatible Siemens load centers that accept Type QT breakers. Featuring a non-common trip mechanism and a 10kAIC rating at 120/240VAC, this legacy breaker is replaced by the Q24020CT2 model.
What panels are compatible with the Siemens Q24020 circuit breaker?
The Q24020 is designed for use in Siemens load centers that accept Type QT quadplex breakers. It requires two full panel spaces and a notched bus bar designed for CTL (Circuit Total Limiting) breakers.
What circuits does the Q24020 quadplex breaker provide?
This quad breaker provides two independent 240V circuits in a single unit: one 40A double-pole circuit and one 20A double-pole circuit. It occupies two standard 1-inch spaces in the panel.
Does the Q24020 feature a common trip mechanism?
No, the standard Q24020 features a non-common trip mechanism. If a common trip mechanism is required for your application, you will need the Q24020CT2 model.
Does the Q24020 require a CTL panel?
Yes, as a standard Type QT breaker, it features a rejection clip and is designed exclusively for CTL (Circuit Total Limiting) load centers that are rated to accept tandem or quadplex breakers. It will not seat properly in non-CTL spaces.
What wire sizes are accepted by the lugs on the Q24020?
The terminals accept 8 to 6 AWG copper wire or 8 to 4 AWG aluminum wire. Ensure you torque the lugs to the manufacturer specifications during installation.
Is the Q24020 the same as the Q24020CT2?
They are similar in amperage and footprint, but the Q24020 has a non-common trip mechanism, whereas the Q24020CT2 features a common trip mechanism. Check your local electrical code requirements to determine which version is required for your specific load.
What is the difference between the Q24020 and the Q24020NC?
The Q24020 is a CTL (Circuit Total Limiting) breaker with a rejection clip, designed for modern panels. The Q24020NC is a non-CTL version without the rejection clip, intended for use in older panels that do not have notched bus bars.
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Reviews
Review summary
Customers rate this product 5.0 out of 5 based on 48 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.