Find the Square D breaker catalog number for a given amperage and pole count
Pick the Square D line, pole count, and amperage to get a catalog-number candidate with its interrupting rating, limited to the audited QO, QOB, and Homeline tables.
Use this breaker part number lookup when you know the amperage and pole count but need the matching Square D catalog number. Pick QO plug-on, QOB bolt-on, or Homeline, then choose an amperage from the published ladder for that line and pole count.
The finder assembles the number from the Square D ordering grammar and decodes it back through the same audited tables before showing it. The result states whether the exact row was individually verified or whether the number is grammar valid and backed by the interrupting-rating matrix. It does not check price, availability, panel compatibility, series rating, selective coordination, or code approval.
Already have a number? Decode it. Read every segment against the same source tables.
Square D Breaker Decoder →Size the branch conductors after the breaker rating and load basis are confirmed.
Wire Sizing Calculator →Check whether a proposed load fits the selected breaker and panel capacity.
Can I Run This On That? →How It Works
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Enter requirements
Choose QO plug-on, QOB bolt-on, or Homeline, then select the pole count and an amperage from the sourced ladder. The amperage field is not freeform.
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Review candidate numbers
Read the primary catalog-number candidate and its status. A verified catalog row was individually enumerated. A grammar-valid row is assembled from the ordering rules and backed by a sourced interrupting-rating band.
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Read the code breakdown
Check the series, pole, amperage, rating, and feature segments produced by the round-trip decoder. The finder suppresses a number if the decoded result does not agree with the selected inputs.
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Check assumptions and gaps
Read the interrupting-rating notes, scope boundary, and panel-listing caution. A needs-source result shows no number until the missing manufacturer row is available.
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Share or export
Save the selection in a shareable URL or export the candidate and its source notes to CSV or PDF. Verify the final choice against the current catalog, breaker label, and panelboard label.
Built For
- A service electrician knows the panel calls for a QO plug-on, 2-pole, 20 A breaker. The finder returns the sourced candidate and its rating breakdown, then the electrician checks the panelboard label and the physical breaker label before ordering.
- An estimator has a Homeline panel schedule with a 1-pole 20 A branch. The finder returns the verified Homeline row, and the estimator confirms that the catalog number is listed on the panel label before adding it to the takeoff.
- A maintenance technician is told a replacement must meet 22 kA. The finder separates the VH high-interrupt candidate from 10 kA base and H variants, then the technician verifies available fault current, the panel listing, and the current manufacturer table.
Features & Capabilities
What changes between QO, QOB, and Homeline
QO is plug-on, QOB is bolt-on, and Homeline is a separate plug-on line with its own bus design and catalog prefix. The line, pole count, and amperage are selected only from the packet data.
Interrupting rating and what the suffixes mean
Base, H, and VH results are kept separate so the voltage and interrupting-rating differences remain visible.
What the number means
Every candidate is decoded back through the audited parser. The displayed breakdown comes from that decode, not from a second hand-written explanation table. Already have a number? Decode it.
Will it fit my panel?
Physically identical does not mean listed for the panel. Check the panelboard label for tested and listed catalog numbers, then keep the reviewed selection with the share and export controls.
Worked example: QO 2-pole 20 A
| Field | Value | Source basis |
|---|---|---|
| Input | QO plug-on, 2 poles, 20 A, no minimum interrupting rating | Selected parameters |
| Catalog number | QO220 | Verified CATALOG_ROWS entry |
| Series | QO plug-on | CATALOG_ROWS.series |
| Poles | 2 | CATALOG_ROWS.poles |
| Amperage | 20 A | CATALOG_ROWS.amp_rating_a |
| Voltage | 120/240 Vac | CATALOG_ROWS.voltage_rating_vac |
| Interrupting rating | 10 kA AIR | CATALOG_ROWS.interrupting_rating_aic |
| At 48 VDC | 5 kA | QO_QOB_AIC row for QO, 2 poles, 10 to 70 A |
| Segment breakdown | QO = plug-on series; 2 = pole count; 20 = ampere rating | Round-trip decoder |
| Rating variants | QO220VH = 22 kA; QO220H = 240 Vac common-trip at 10 kA | QO_QOB_AIC sourced bands |
Assumptions
- The selected amperage comes from the published standard ladder for the chosen line and pole count.
- The interrupting rating is read from the Schneider matrix on the full catalog number. It is never inferred from one suffix letter.
- A grammar-valid result is backed by the ordering grammar and an interrupting-rating band but may not be an individually enumerated catalog row.
- The optional minimum interrupting rating is a filter. It does not calculate available fault current at the panel.
Limitations
- Physically identical does not mean listed for the panel. Check the panelboard label for the breaker catalog numbers tested and listed for that panel.
- Series rating, selective coordination, available fault current, NEC acceptability, and AHJ approval are outside this tool.
- Price, availability, lifecycle status, and lead time are not checked.
- Siemens QP, Eaton BR and CH, PowerPacT, QOU, QOH, QH, QHB, dual-function, HID, switching-neutral, EPD, and high-magnetic feature breakers are outside the V1 build set.
- The current Schneider digest, the physical breaker label, and the panelboard label control the final order.
References
- Square D QO and QOB Miniature Circuit Breakers Catalog (Table 1 Interrupting Ratings) + Digest QO/Homeline catalog page. Document number: 0730CT9801R1/08. Revision: 07/2008 (Class 730); cross-checked vs 2020 Digest page + se.com, pin Digest 178 page/table before launch. Clause or table: Table 1: Interrupting Ratings (p5); Table 1.1 (QO) / Table 1.36 (HOM). Captured on 2026-06-27.
- Homeline source carried by the packet: USESI brochure 660697, Table 1.36.
- Current Schneider Electric Digest Plus QO Plug-On Circuit Breakers table. It independently enumerates QO220 and QO220H, places QO220H in the 2-pole 240 Vac common-trip column, and rates the row 10 k AIR. Accessed 2026-07-27.
- Current Schneider product records independently corroborate QO220, QO220VH, and HOM120. Accessed 2026-07-27.
- Schneider Electric FAQ FA120545, Can the QO branch circuit breakers be installed in the Homeline load centers OR can Homeline branch circuit breakers be installed in QO load centers? It confirms that QO and Homeline branch breakers are limited to their matching load-center lines. Accessed 2026-07-27.
- Schneider Electric FAQ FA174503, What breakers does a QO Load Center take? Last modified 2026-02-26. It lists accepted QO families and states that QOB and HOM variants do not fit a QO load center. Accessed 2026-07-27.
- Schneider Electric FAQ FA109246, Will other manufacturers branch circuit breakers work in Square D QO or Homeline load centers? Last modified 2026-04-17. It states that the load centers are tested, listed, and labeled for Square D circuit breakers. Accessed 2026-07-27.