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Siemens Q140 Miniature Circuit Breaker
- 40A
- 1 Pole
- Plug-On
Siemens
Q140
Miniature Circuit Breaker
Brand
Siemens
SKU
Q140
Quantity
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Siemens Q140 - 40A 1 Pole Miniature Circuit Breaker
New
Quantity
Quantity
Siemens Q140 - 40A 1 Pole Miniature Circuit Breaker
New
Quantity
| Brand | Siemens |
|---|---|
| Part Number | Q140 |
| Series | Q |
| Amperage | 40A |
| Poles | 1 |
| Mounting Style | Plug-On |
| Voltage | 120VAC |
| Phase | 1 |
| AIC Rating | 10kA @ 120VAC |
| Frame Type | Q |
|---|---|
| Terminal Type | Lugs |
| For Use With | Siemens Load Centers, Murray Load Centers (post-2002), Siemens Panelboards |
| Wire Gauge | 8-6 AWG (Cu), 8-4 AWG (Al) |
| Max Wire | 6 AWG (Cu), 4 AWG (Al) |
| Min Wire | 8 AWG |
| Trip Technology | Thermal Magnetic |
|---|---|
| Trip Function Code | LI |
| Trip Function | Long-Time, Instantaneous |
| Trip Adjustability | Fixed |
| Available Options | Padlock Attachment |
|---|---|
| Standards | CSA C22.2 No. 5, HACR, UL 489 |
| Approval | CSA, UL |
| Temp Rating | 40C |
| Construction Features | Insta-Wire, HACR Rated |
Sold out
Quantity
Siemens Q140 - 40A 1 Pole Miniature Circuit Breaker
Re-Certified
Quantity
| Brand | Siemens |
|---|---|
| Part Number | Q140-R |
| Series | Q |
| Amperage | 40A |
| Poles | 1 |
| Mounting Style | Plug-On |
| Voltage | 120VAC |
| Phase | 1 |
| AIC Rating | 10kA @ 120VAC |
| Frame Type | Q |
|---|---|
| Terminal Type | Lugs |
| For Use With | Siemens Load Centers, Murray Load Centers (post-2002), Siemens Panelboards |
| Wire Gauge | 8-6 AWG (Cu), 8-4 AWG (Al) |
| Max Wire | 6 AWG (Cu), 4 AWG (Al) |
| Min Wire | 8 AWG |
| Trip Technology | Thermal Magnetic |
|---|---|
| Trip Function Code | LI |
| Trip Function | Long-Time, Instantaneous |
| Trip Adjustability | Fixed |
| Available Options | Padlock Attachment |
|---|---|
| Standards | CSA C22.2 No. 5, HACR, UL 489 |
| Approval | CSA, UL |
| Temp Rating | 40C |
| Construction Features | Insta-Wire, HACR Rated |
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Description
Serving as a dependable solution for residential and light commercial distribution, this 40A single-pole device provides standard 10kAIC thermal-magnetic protection. It snaps securely into Siemens load centers and is fully UL-listed for use in Murray enclosures manufactured after 2002. Electricians frequently utilize this size for dedicated equipment circuits or subpanel feeds. The HACR certification guarantees safe integration with heating and cooling systems across various installations.Specifications
| Brand | Siemens |
|---|---|
| Part Number | Q140 |
| Series | Q |
| Amperage | 40A |
| Poles | 1 |
| Mounting Style | Plug-On |
| Voltage | 120VAC |
| Phase | 1 |
| AIC Rating | 10kA @ 120VAC |
| Frame Type | Q |
|---|---|
| Terminal Type | Lugs |
| For Use With | Siemens Load Centers, Murray Load Centers (post-2002), Siemens Panelboards |
| Wire Gauge | 8-6 AWG (Cu), 8-4 AWG (Al) |
| Max Wire | 6 AWG (Cu), 4 AWG (Al) |
| Min Wire | 8 AWG |
| Trip Technology | Thermal Magnetic |
|---|---|
| Trip Function Code | LI |
| Trip Function | Long-Time, Instantaneous |
| Trip Adjustability | Fixed |
| Available Options | Padlock Attachment |
|---|---|
| Standards | CSA C22.2 No. 5, HACR, UL 489 |
| Approval | CSA, UL |
| Temp Rating | 40C |
| Construction Features | Insta-Wire, HACR Rated |
Product FAQs
8 answersCan I use the Siemens Q140 in a Murray load center?
Yes, the Siemens Q140 is UL listed for use in Murray load centers manufactured after 2002. Siemens acquired Murray, making QP breakers the approved replacements for these panels.
What is the difference between a Q140 and a QP140?
There is no difference in the physical breaker. Q140 is the Siemens catalog number, while QP refers to the breaker family and frame type. They are the exact same thermal magnetic circuit breaker.
Does the Siemens Q140 replace older ITE or Gould breakers?
Yes, the Siemens Q140 is the direct replacement for older ITE and Gould 40A, 1-pole QP type circuit breakers. It is designed to fit the same load centers and meter combinations.
Can I install the Siemens Q140 in a Square D or Eaton load center?
No, Siemens QP breakers are not UL listed for use in Square D, Eaton, or GE load centers. They are strictly designed for Siemens, post-2002 Murray, ITE, and Gould panels.
What is the recommended lug torque for the Q140 breaker?
For the Siemens Q140, the recommended torque is 40 lb-in for 8 AWG wire, and 45 lb-in for 6 AWG and 4 AWG wire. Always verify the exact torque specifications printed on the side of the breaker before installation.
Is the Siemens Q140 HACR rated?
Yes, the Siemens Q140 is HACR rated, making it suitable for use with heating, air conditioning, and refrigeration equipment that requires this specific certification.
Can I use this 1-pole Q140 breaker for a 240V application?
No, the Q140 is a 1-pole breaker rated for 120VAC. For a 240V application requiring 40 amps, you must use a 2-pole breaker, such as the Siemens Q240.
Does the Q140 provide GFCI or AFCI protection?
No, the Q140 is a standard thermal magnetic circuit breaker. It does not provide Ground Fault Circuit Interrupter (GFCI) or Arc Fault Circuit Interrupter (AFCI) protection. If your circuit requires dual function or AFCI protection, you will need a QAF or QF series breaker.
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Parcel shipments with item value over $99 qualify for free economy shipping within the continental US. Please call to confirm special handling instructions. We do not charge a handling fee or require a minimum amount on any order. SuperBreakers does not ship on customer accounts.
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All International orders require a $1,000 minimum order threshold. Due to the special nature of these shipments, we require that these be placed with a SuperBreakers representative. Additional shipping and instructions will apply. All International Orders are Non-Cancel and Non-Refundable.
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.