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Siemens EF3B040 Molded Case Circuit Breaker
- 40A
- 3 Pole
- Bolt-On
Siemens
EF3B040
Molded Case Circuit Breaker
Brand
Siemens
SKU
EF3B040
Quantity
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Siemens EF3B040 - 40A 3 Pole Molded Case Circuit Breaker
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Description
Engineered for commercial applications, this 40A three-pole molded case circuit breaker provides reliable fixed thermal-magnetic protection. Designed for older infrastructure, it installs into Siemens P1, P2, and P3 panelboards as well as legacy I-T-E enclosures. For modern upgrades, this unit is replaced by the current ED63B040 model. Rated for 18kA at 240VAC and 14kA at 480VAC, it handles standard facility distribution needs while utilizing standard load side lugs.Specifications
| Brand | Siemens |
|---|---|
| Part Number | EF3B040-R |
| Series | EF |
| Amperage | 40A |
| Poles | 3 |
| Mounting Style | Bolt-On |
| Voltage | 240VAC, 480VAC, 600VAC, 250VDC |
| Phase | 3 |
| AIC Rating | 18kA @ 240VAC, 14kA @ 480VAC, 14kA @ 600VAC, 10kA @ 250VDC |
| Terminal Type | Lugs |
|---|---|
| For Use With | Siemens P1, P2, P3 Panelboards, Legacy I-T-E Panelboards |
| Wire Gauge | 10-1/0 AWG (Cu/Al) |
| Max Wire | 1/0 AWG |
| Min Wire | 10 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, Undervoltage Release, Alarm Switch |
|---|---|
| Accessories | Load Side Lugs Included |
| Standards | NEMA AB-1, UL 489 |
| Approval | CSA, UL |
| Temp Rating | 40C |
| Construction Features | HACR Rated, Non-Interchangeable Trip |
Product FAQs
5 answersIs the Siemens EF3B040 circuit breaker obsolete?
Yes, the EF3B040 is a legacy E-frame breaker that is no longer in active production. For modern panel upgrades, it is typically replaced by the current Siemens ED63B040 model.
Which panelboards are compatible with the EF3B040?
This breaker is designed to install directly into Siemens P1, P2, and P3 panelboards, as well as legacy I-T-E enclosures.
Are load side lugs included with the EF3B040?
Yes, this breaker comes complete with load side lug terminals that accept 10 AWG to 1/0 AWG copper or aluminum conductors.
What type of protection does the trip unit provide?
It features a thermal-magnetic trip unit with fixed thermal and fixed magnetic settings, delivering standard long-time and instantaneous (LI) overcurrent protection.
Is the EF3B040 suitable for HVAC applications?
Yes, this breaker is HACR rated, making it approved for use with heating, air conditioning, and refrigeration equipment.
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Reviews
Review summary
Customers rate this product 5.0 out of 5 based on 2 reviews.
Total 5 star reviews: 2 Total 4 star reviews: 0 Total 3 star reviews: 0 Total 2 star reviews: 0 Total 1 star reviews: 0
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Rating
2 reviews
- VGVictor G.Verified BuyerRated 5 out of 5 stars11/6/25Breakers fit my needs
I wish I would of shopped this I found exact breaker for 400.00 cheaper
- RFRobert F.ReviewingSiemens EF3A100 - 100A 3 Pole Motor Circuit ProtectorI recommend this productRated 5 out of 5 stars7/25/22Fast order and service for a part in good condition
Fast order and service for a part in good condition.