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Siemens Q2125 Molded Case Circuit Breaker
- 125A
- 2 Pole
- Plug-On
Siemens
Q2125
Molded Case Circuit Breaker
Brand
Siemens
SKU
Q2125
Quantity
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Siemens Q2125 - 125A 2 Pole Molded Case Circuit Breaker
New
Quantity
Quantity
Siemens Q2125 - 125A 2 Pole Molded Case Circuit Breaker
New
Quantity
| Brand | Siemens |
|---|---|
| Part Number | Q2125 |
| Series | Q |
| Amperage | 125A |
| Poles | 2 |
| Mounting Style | Plug-On |
| Voltage | 120/240VAC |
| Phase | 1 |
| AIC Rating | 10kA @ 120/240VAC |
| Frame Type | Q |
|---|---|
| Terminal Type | Lugs |
| For Use With | Siemens Load Centers, Siemens P1 Panelboards |
| Wire Gauge | 2-1/0 AWG (Cu), 1/0-2/0 AWG (Al) |
| Max Wire | 2/0 AWG |
| Min Wire | 2 AWG |
| Trip Technology | Thermal Magnetic |
|---|---|
| Trip Function Code | LI |
| Trip Function | Long-Time, Instantaneous |
| Trip Adjustability | Fixed |
| Available Options | Padlock Attachment |
|---|---|
| Standards | UL 489, CSA C22.2 No. 5, HACR Rated |
| Approval | CSA, UL |
| Temp Rating | 40C |
| Construction Features | Common Trip, HACR Rated |
Sold out
Quantity
Siemens Q2125 - 125A 2 Pole Molded Case Circuit Breaker
Re-Certified
Quantity
| Brand | Siemens |
|---|---|
| Part Number | Q2125-R |
| Series | Q |
| Amperage | 125A |
| Poles | 2 |
| Mounting Style | Plug-On |
| Voltage | 120/240VAC |
| Phase | 1 |
| AIC Rating | 10kA @ 120/240VAC |
| Frame Type | Q |
|---|---|
| Terminal Type | Lugs |
| For Use With | Siemens Load Centers, Siemens P1 Panelboards |
| Wire Gauge | 2-1/0 AWG (Cu), 1/0-2/0 AWG (Al) |
| Max Wire | 2/0 AWG |
| Min Wire | 2 AWG |
| Trip Technology | Thermal Magnetic |
|---|---|
| Trip Function Code | LI |
| Trip Function | Long-Time, Instantaneous |
| Trip Adjustability | Fixed |
| Available Options | Padlock Attachment |
|---|---|
| Standards | UL 489, CSA C22.2 No. 5, HACR Rated |
| Approval | CSA, UL |
| Temp Rating | 40C |
| Construction Features | Common Trip, HACR Rated |
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Description
Engineered for residential and commercial distribution, the Siemens Q2125 provides 125A of thermal-magnetic protection against overloads and short circuits. This two-pole plug-on breaker mounts into Siemens load centers and P1 panelboards. It serves as an exact cross-reference replacement for the discontinued MP2125, ensuring seamless compatibility for older installations. Rated for 120/240VAC with a 10kAIC capacity, the unit features common trip functionality and is HACR rated.Specifications
| Brand | Siemens |
|---|---|
| Part Number | Q2125 |
| Series | Q |
| Amperage | 125A |
| Poles | 2 |
| Mounting Style | Plug-On |
| Voltage | 120/240VAC |
| Phase | 1 |
| AIC Rating | 10kA @ 120/240VAC |
| Frame Type | Q |
|---|---|
| Terminal Type | Lugs |
| For Use With | Siemens Load Centers, Siemens P1 Panelboards |
| Wire Gauge | 2-1/0 AWG (Cu), 1/0-2/0 AWG (Al) |
| Max Wire | 2/0 AWG |
| Min Wire | 2 AWG |
| Trip Technology | Thermal Magnetic |
|---|---|
| Trip Function Code | LI |
| Trip Function | Long-Time, Instantaneous |
| Trip Adjustability | Fixed |
| Available Options | Padlock Attachment |
|---|---|
| Standards | UL 489, CSA C22.2 No. 5, HACR Rated |
| Approval | CSA, UL |
| Temp Rating | 40C |
| Construction Features | Common Trip, HACR Rated |
Product FAQs
8 answersWhich load centers are compatible with the Siemens Q2125 breaker?
The Q2125 is a Type QP plug-on breaker designed for Siemens EQ, PL, ES, and Ultimate series load centers, as well as Siemens P1 panelboards.
Can I use the Siemens Q2125 to replace an old ITE or Gould breaker?
Yes. Siemens manufactures current-generation Type QP breakers as direct, code-compliant replacements for legacy ITE and Gould Q2125 branch breakers.
How many panel spaces does the Q2125 circuit breaker require?
This 2-pole Type QP breaker requires two adjacent standard 1-inch panel spaces, utilizing 2 inches of total bus space.
What accessory is required if the Q2125 is used as a back-fed main breaker?
When installing this Type QP breaker as a back-fed main, the National Electrical Code requires a hold-down retainer clip, such as the Siemens ECMBR1, to mechanically secure the breaker to the panel bus.
Are the lugs on the Q2125 breaker rated for aluminum conductors?
Yes, the factory-installed lugs accept both copper and aluminum wiring. When using aluminum conductors, the terminals accommodate 1/0 AWG to 2/0 AWG wire sizes.
What applications is a 125A 2-pole Type QP breaker typically used for?
A 125-amp branch breaker is frequently used as a feeder breaker for residential subpanels, outbuildings, or to supply power to heavy-duty electrical equipment, provided the panel bus is rated for the load.
Does the Q2125 trip both poles simultaneously during a fault?
Yes. The breaker features an internal common trip mechanism. If a thermal overload or short circuit is detected on either leg, both poles disconnect simultaneously to ensure system safety.
Is the Siemens Q2125 breaker HACR rated?
Yes, this thermal-magnetic breaker is HACR rated, making it suitable and approved for protecting heating, air conditioning, and refrigeration equipment circuits.
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Reviews
Review summary
Customers rate this product 5.0 out of 5 based on 47 reviews.
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.
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Rating
47 reviews
- CGCrocefissa G.Verified BuyerReviewingSiemens Q115 - 15A 1 Pole Miniature Circuit BreakerI recommend this productRated 5 out of 5 stars9/18/26Quick delivery and great price.
The circuit breakers are at a great cost.
- JBJason B.Verified BuyerReviewingSiemens Q2150B - 150A 2 Pole Molded Case Circuit BreakerI recommend this productRated 5 out of 5 stars9/18/26Great experience
The product was exactly what I needed and it arrived on time.
- DQDon Q.Verified BuyerReviewingSiemens Q3100 - 100A 3 Pole Molded Case Circuit BreakerI recommend this productRated 5 out of 5 stars9/14/26Siemens breaker
Great customer experience, great prices and fast shipping... Definitely will be buying her again.
- CSChristopher S.Verified BuyerRated 5 out of 5 stars8/12/26Siemens 60
Perfect new condition
- GSGeorge S.Verified BuyerReviewingSiemens Q2150B - 150A 2 Pole Molded Case Circuit BreakerI recommend this productRated 5 out of 5 stars3/4/26Great service
Every time I call or go online you have the parts I'm looking for.