Eaton CH vs Siemens QP: Complete Comparison Guide

Eaton CH and Siemens QP are both popular residential circuit breaker lines, but they serve different market segments. The Eaton CH is a premium breaker with a classified 22,000 AIC interrupting rating — more than double the Siemens QP's standard 10,000 AIC. This makes the CH the better choice for locations with high available fault current. However, the QP is more affordable and offers better panel expansion options with tandem breakers. This guide breaks down every difference to help you understand which line fits your needs.

Eaton CH vs Siemens QP Comparison

NOT Interchangeable — Different Manufacturers, Different Panels

Eaton CH breakers will NOT fit in a Siemens panel, and Siemens QP breakers will NOT fit in an Eaton CH panel. These are products from different manufacturers with completely different bus stab designs, mounting mechanisms, and panel slot dimensions. If you have an existing panel, you must buy breakers that match your panel manufacturer and type. This comparison is most relevant for new construction or panel upgrade decisions.

The AIC Rating Advantage (Eaton CH)

The biggest technical difference is the AIC (Ampere Interrupting Capacity) rating. Eaton CH breakers are classified at 22,000 AIC — meaning they can safely interrupt fault currents up to 22,000 amps. Siemens QP is rated at 10,000 AIC. This matters when your panel is located near a utility transformer, in a commercial area with large service, or anywhere the utility has identified available fault current above 10,000A. In these locations, a 10,000 AIC breaker may not safely clear a fault, potentially causing an arc flash or fire.

When the AIC Rating Matters

For most suburban residential installations, available fault current at the panel is well under 10,000A, making both CH and QP adequate. However, if your home is within 50 feet of a pad-mounted transformer, in a dense urban area, or if your utility has provided a fault current study showing available current above 10,000A, the CH's 22,000 AIC rating provides a genuine safety advantage. Some jurisdictions now require fault current labels on panels — check yours.

The Expansion Advantage (Siemens QP/QT)

Siemens panels offer better expansion options through the QT tandem breaker line. QT breakers fit two circuits in one panel slot, letting you add circuits without upgrading the panel. While Eaton does make CHT tandem breakers, the Siemens QT line is more widely available and more Siemens panels accept them. If future expansion is a priority, Siemens panels with tandem-rated positions offer more flexibility.

Price and Availability

Siemens QP breakers are typically $3–$5 cheaper per unit than Eaton CH breakers. A standard QP120 runs $5–$9, while a CH120 runs $8–$14. The price premium for CH reflects the higher AIC rating and Eaton's manufacturing costs. Both lines are available at major retailers, though CH may be harder to find in the eastern US where Eaton BR dominates. Siemens QP is available nationwide at Home Depot, Lowe's, and electrical supply houses.

Verdict

If you already have a panel, match your breaker to the panel type. For new installations, choose Eaton CH if you need the 22,000 AIC rating (near transformers, high fault current areas) or want the extra safety margin. Choose Siemens QP if budget is a priority, you want better tandem expansion options, or your available fault current is well under 10,000A. Both are quality products — the CH simply offers more fault current protection at a higher price point.

Frequently Asked Questions

Can I use an Eaton CH breaker in a Siemens panel?

No. Eaton CH and Siemens QP breakers are from different manufacturers with incompatible designs. They will NOT fit in each other's panels. Always match breakers to your panel manufacturer and type.

Is Eaton CH better than Siemens QP?

CH has a higher AIC rating (22,000A vs 10,000A), making it better for high fault current locations. QP is cheaper and has better tandem options. For standard residential use under 10,000A available fault current, both are adequate.

Why is the AIC rating important?

AIC (Ampere Interrupting Capacity) is the maximum fault current the breaker can safely interrupt. If available fault current at your panel exceeds the breaker's AIC rating, the breaker may fail to clear the fault safely, potentially causing an arc flash or fire.

How do I find out my available fault current?

Contact your utility company and request the available fault current at your service entrance. Some utilities provide this information on your meter panel label. You can also hire an electrician to perform a fault current study.