Reading a Cutler Hammer Catalog Number: Frame, Poles, Amps, in That Order
Breakers are the one product category where guessing is dangerous rather than merely expensive. A breaker has to be listed for the panel it goes into, and no amount of physical fit proves that. The good news is that Cutler Hammer catalog numbers are readable. On 184 of the 218 parts here the number resolves cleanly into frame, pole count and amperage, and once you can read that, the collection stops being a wall of codes.
The frame is the first and least reversible decision
The frame is the letter group at the front of the number, and it decides the panel the breaker belongs in, the mounting method and the interrupting rating. Get the frame wrong and nothing else matters. Two terms in the table below are worth defining first: a quad is a single device holding two independent two pole breakers, and a tandem holds two single pole breakers in one slot. The nine largest frames below account for 157 of the 218 breakers here, and smaller frames make up the rest. Everything on this page also sits in circuit breakers, where you can compare Cutler Hammer against the other breaker manufacturers on one grid.
BAB is the largest frame here at 34 parts, bolt-on, covering 15A to 125A at 120/240V with a 10 kAIC interrupting rating. BR at 26 parts is plug-on, 15A to 110A at 120/240V, also 10 kAIC. QBHW at 21 parts is bolt-on across 15A to 125A at 120/240V but rated 22 kAIC.
GHB is the 480V frame, 21 bolt-on parts from 15A to 100A rated 14 kAIC, and QC adds 18 bolt-on parts from 10A to 100A at 120/240V at 10 kAIC. The BQ and BQC quad and tandem group covers 15 plug-on parts from 15A to 50A at 10 kAIC, and QBGFT with QBGFEP covers 11 bolt-on ground fault parts over the same amperage span.
Two smaller frames matter for specific reasons. BRH is seven plug-on parts from 15A to 125A at 120/240V rated 22 kAIC. HMCP is four motor circuit protectors from 30A to 150A at 480V and 600V, rated as high as 65 kAIC.
Two comparisons in that table do real work. BR and BRH are the same physical frame at different interrupting ratings, 10 kAIC against 22 kAIC, so a panel with a higher available fault current needs the BRH part rather than the cheaper BR. GHB is the 480V frame, and it is the one to reach for on three phase commercial gear where the BAB and BR families do not belong.
What the digits after the frame mean
Once the frame letters end, the next digit is the pole count and the digits after that are the amperage. QC3015 is a QC frame, three pole, 15 amp. BAB2015 is a BAB frame, two pole, 15 amp. GHB2100 is a GHB frame, two pole, 100 amp. The pattern is consistent enough to read a quote without a catalog open beside you.
The leading letters are the frame, as in GHB, and they set the panel, the mounting and the interrupting rating. The next single digit is the pole count, running 1 through 4. The digits after that are the amperage. Any trailing letters mark a variant, such as H for a higher rating or GF for a ground fault version.
The trailing letters are the one segment not to read from memory. A trailing H does not consistently mean the same thing across every frame in this range, so treat it as a flag to open the listing rather than as a decoded value. Broader background on panel and overcurrent selection sits in the electrical guides.
Quad and tandem numbers double up
Eighteen parts here use a doubled number because the device holds two independent breakers in one body. BQ240230 is a four pole quad made of a two pole 40 amp section and a two pole 30 amp section, and the title confirms it as 40/30A. BRD230250 reads the same way as 30 amp and 50 amp. BQ2202115 carries three values because the device combines three sections.
The reason to care is space and listing. A quad occupies the physical width of two breakers while providing four poles, which is how a full panel gets another circuit without a subpanel. It also has to be listed for that specific loadcenter, and quad and tandem acceptance varies by panel rather than by breaker, so the panel label is the authority. Larger distribution equipment across the catalog sits in power and distribution.
Cutler Hammer, Eaton and Westinghouse on the same shelf
Eaton's own product history states that in 1994 Eaton acquired the Distribution and Control Business Unit of Westinghouse and integrated it with its Cutler-Hammer business unit. The practical result is that one catalog number can appear in the channel under three different brand names, and it shows up inside this catalog too. Of the 218 titles in this collection, 182 say Cutler Hammer, 17 say Eaton, 10 say Eaton Cutler Hammer and two say Westinghouse.
Lumera lists Cutler Hammer and Eaton as separate collections and there is no catalog number shared between them, so they are complementary rather than duplicated. Several frames, however, are split across both. If a search in one collection comes up empty, the table below says where else to look. Every figure was counted from the live collections rather than taken from a catalog.
Four frames sit in both collections. BR is 26 parts here against nine in the Eaton collection and CH splits evenly at three each, so search both. BRH is mostly here at seven against two, while CHF leans the other way at two here against nine, and BRP likewise at two against four. QBGFEP is four here and two there.
Five frames appear only in this collection: BAB, GHB, QC, QBHW and HMCP. Going the other way, BRN, CHFN, BD and the surge devices are in the Eaton collection and not here.
One caution that belongs on every page like this. A shared brand lineage is not a statement that any two breakers substitute for each other. Match the catalog number, then confirm the panel is listed to accept that breaker, and treat the panel label rather than the brand name as the authority. Where the panel is a different manufacturer entirely, such as the Square D range, assume the breakers are not interchangeable unless the panel label explicitly says otherwise.
Where these breakers sit in the catalog
All 218 parts appear in both the circuit breaker collection and the power distribution collection, so the brand is fully cross-shoppable by type. Nothing from this brand appears in surge protection, and neither do the three plug-on surge devices in the sister Eaton collection, so panel-mounted surge units are reachable only from the brand pages.
The collection holds one item that is not a breaker at all. BRSF125 is a sub feed lug block for a BR loadcenter, filed under the breaker product type. Read the title rather than the type on that one.
What to confirm before ordering a breaker
The fields below decide whether the device is safe and legal in the panel, not just whether it fits. Overcurrent protection is inspected and the authority having jurisdiction has the final say. That boundary is set out in Lumera's installation and code disclaimer.
- Panel listing. The panel label lists which breakers it accepts. That label governs, not the brand name or the physical fit.
- Frame. BAB, BR, QC, GHB and the rest are not interchangeable with each other.
- Mounting. Bolt-on and plug-on are different panel interiors. Titles here name 101 bolt-on and 54 plug-on parts.
- Interrupting rating. From 10 kAIC to 65 kAIC across the range. This must meet or exceed the available fault current at the panel.
- Voltage. 120/240V on 113 parts, 240V on 53, 480V on 37, plus a small number at 600V and 277V.
- Pole count and amperage. Read both from the catalog number and confirm against the title, since a few titles and numbers disagree.
- Device type. Standard thermal magnetic, GFCI, arc fault, tandem, quad or motor circuit protector. A motor circuit protector is not a branch circuit breaker.
- Quad and tandem acceptance. Set by the loadcenter, not by the breaker. Check the panel schedule before ordering.
Frame, panel and brand-name questions on Cutler Hammer breakers
Is a Cutler Hammer breaker the same as an Eaton breaker?
They come from the same manufacturer lineage, and Eaton's published product history describes integrating the Westinghouse distribution and control business with its Cutler-Hammer business in 1994. That is why you see the same catalog numbers listed under Cutler Hammer, Eaton and sometimes Westinghouse. It is not a license to substitute. Match the catalog number, then confirm the panel label lists that breaker, because acceptance is decided by the panel.
What is the difference between BR and BRH?
Interrupting rating. Both are the same plug-on frame across the same amperage span, but the BR parts here are rated 10 kAIC and the BRH parts are rated 22 kAIC. If the available fault current at your panel exceeds 10,000 amps, the BR part is not adequate and the BRH is the one to specify. The higher rating costs more and there is no reason to pay for it where the fault current does not require it.
Which frame do I need for a 480 volt panel?
In this range that is GHB, which covers 21 parts from 15A to 100A at 480V with a 14 kAIC rating. The BAB, BR, QC and QBHW families here are 120/240V and 240V devices and do not belong on a 480V system. There are also four HMCP motor circuit protectors rated to 600V, but those protect motor branch circuits and are not general purpose breakers.
What is a quad breaker and will it fit my panel?
A quad is one device containing two independent two pole breakers, so it delivers four poles in the width of two. BQ240230 is a 40 amp and a 30 amp section in one body. Whether it fits is decided entirely by the loadcenter, since panels are listed for specific tandem and quad devices and many positions in a panel will not accept them. Read the panel label and the schedule before ordering.
Can I put a Cutler Hammer breaker in another manufacturer's panel?
Only where the panel label specifically lists it, which is uncommon across manufacturers. Physical fit proves nothing, because the listing covers the bus connection, the interrupting rating and the way the device seats under fault conditions. Treat a breaker from one manufacturer in another manufacturer's panel as unacceptable unless the label says otherwise in writing.
How do I read a catalog number I have never seen?
Take the letters at the front as the frame, the next single digit as the pole count, and the digits after that as the amperage. On that reading BAB3070 comes out as a BAB frame, three pole, 70 amp. Where the number has two amperage groups it is a quad or tandem device. Trailing letters vary in meaning, so open the listing rather than guessing at them.
