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Square D Q1B340 Molded Case Circuit Breaker
- 40A
- 3 Pole
- Bolt-On
Square D
Q1B340
Molded Case Circuit Breaker
Brand
Square D
SKU
Q1B340
Quantity
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Square D Q1B340 - 40A 3 Pole Molded Case Circuit Breaker
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Description
Providing 40A of reliable overcurrent defense, the Square D Q1B340 is a 3-pole molded case circuit breaker designed for 240VAC systems. It features fixed thermal and magnetic trip units to handle overloads, boasting a 10kAIC rating. Designed for bolt-on installation, this breaker fits into older Square D NQO and NQOB panelboards. Replacing a Q1B breaker with a newer QOB model requires an SK5668 bracket, making this exact replacement a simpler solution. It complies with UL 489 standards.Specifications
| Brand | Square D |
|---|---|
| Part Number | Q1B340 |
| Series | Q1B |
| Amperage | 40A |
| Poles | 3 |
| Mounting Style | Bolt-On |
| Voltage | 240VAC |
| Phase | 3 |
| AIC Rating | 10kA @ 240VAC |
| Frame Type | Q1B |
|---|---|
| Terminal Type | Box Lugs |
| For Use With | Square D NQO, NQOB Panelboards |
| Wire Gauge | #8-2 AWG |
| Max Wire | 2 AWG |
| Min Wire | 8 AWG |
| Trip Technology | Thermal Magnetic |
|---|---|
| Trip Function Code | LI |
| Trip Function | Long-Time, Instantaneous |
| Trip Adjustability | Fixed Thermal, Fixed Magnetic |
| Available Options | Shunt Trip, Auxiliary Switch, Alarm Switch |
|---|---|
| Accessories | Load Side Lugs Included |
| Standards | CSA C22.2 No. 5, HACR Rated, UL 489 |
| Approval | CSA, UL |
| Temp Rating | 40C |
| Construction Features | Visual Trip Indicator, Common Trip |
Product FAQs
4 answersWhich panelboards are compatible with the Q1B340 breaker?
This breaker is designed specifically for older Square D NQO and NQOB commercial panelboards that require bolt-on connections.
Can a newer QOB breaker replace the legacy Q1B340?
Yes, a newer QOB model can be substituted, but it requires an SK5668 mounting bracket to fit properly. Using an exact Q1B340 replacement avoids the need for adapter kits.
What wire gauge range is supported by the Q1B340 terminals?
The box lugs on this breaker accept wire sizes from 8 AWG to 2 AWG. Always verify the correct conductor size for your 40A load and temperature ratings according to the National Electrical Code.
What type of protection do the LI trip functions provide?
The Long-Time and Instantaneous (LI) designations refer to the thermal-magnetic trip unit. The thermal element provides a delayed trip for sustained overloads, while the magnetic element trips instantly during short circuits.
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Reviews
Review summary
Customers rate this product 5.0 out of 5 based on 1 review.
Total 5 star reviews: 1 Total 4 star reviews: 0 Total 3 star reviews: 0 Total 2 star reviews: 0 Total 1 star reviews: 0
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1 review
- MCMichael C.ReviewingSquare D Q1B3100 - 100A 3 Pole Molded Case Circuit BreakerI recommend this productRated 5 out of 5 stars2/11/22Fast Service.
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