Engineered for high-demand residential applications, the Siemens MP290 is a 90A, two-pole miniature breaker. It provides robust thermal-magnetic protection for 120/240V systems. This legacy plug-on breaker is specifically designed to fit older Murray and Siemens load centers. It serves as a direct replacement for aging infrastructure and is officially superseded by the Q290 model, ensuring continued compatibility. With a 10kA interrupting capacity, the breaker features a common trip mechanism.
What is the direct replacement for the Murray MP290?
Siemens acquired Murray and officially superseded the MP-T series with the Siemens QP line. The Siemens Q290 is the direct, manufacturer-approved replacement for the legacy Murray MP290.
Can I install a Siemens Q290 in a panel that specifies Murray MP290?
Yes. A UL classification letter confirms that Siemens QP breakers are authorized replacements for Murray MP-T breakers. They are physically and electrically identical and can be safely installed in panels labeled for Type MP, MP-A, or MP-C breakers.
How much panel space is required to install the MP290?
The MP290 is a standard full-size breaker that requires two 1-inch spaces (2 inches total) on the panel bus.
What wire sizes are accepted by the MP290 terminals?
The box lugs on this breaker accept 8 AWG to 2/0 AWG copper or aluminum conductors. Ensure proper torque is applied during installation as specified on the breaker face or panel label.
What type of protection does the LI trip function provide?
The LI designation indicates a thermal-magnetic trip unit with Long-Time and Instantaneous functions. The thermal element (Long-Time) prevents overheating from sustained overloads, while the magnetic element (Instantaneous) trips immediately during a short circuit.
Can the MP290 be used as a back-fed main breaker?
Yes, it can be used as a back-fed main breaker in compatible load centers, provided it is secured with an approved breaker hold-down retainer kit (such as the ECMBR1) to comply with NEC requirements.
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Reviews
Review summary
Customers rate this product 5.0 out of 5 based on 4 reviews.
Thank you so much for sending me a 100 amp breaker that was in the condition that you said it would be in.With out your breaker I would still be in the dark Thank you David