Siemens EF3B025 Molded Case Circuit Breaker
- 25A
- 3 Pole
- Bolt-On
Quantity
Siemens EF3B025 - 25A 3 Pole Molded Case Circuit Breaker
Re-Certified
Quantity
Description
Serving commercial facilities, the Siemens EF3B025 is a 3-pole, 25A molded case circuit breaker. This legacy EF frame device provides essential thermal-magnetic protection for circuits up to 600VAC. Designed for secure installation, it bolts into Siemens P1, P2, P3, and vintage I-T-E panelboards. When upgrading panels, the ED63B025 serves as its modern substitute. With a capacity of 14kAIC at 480V and 18kAIC at 240V, this HACR-rated breaker ensures reliable performance for HVAC loads.Specifications
| Brand | Siemens |
|---|---|
| Part Number | EF3B025 |
| Series | EF |
| Amperage | 25A |
| Poles | 3 |
| Mounting Style | Bolt-On |
| Voltage | 240VAC, 480VAC, 600VAC, 250VDC |
| Phase | 3 |
| AIC Rating | 18kA @ 240VAC, 14kA @ 480VAC, 14kA @ 600VAC, 10kA @ 250VDC |
| Frame Type | EF |
|---|---|
| Terminal Type | Lugs |
| For Use With | Siemens P1, P2, P3 Panelboards, Legacy I-T-E Panelboards |
| Wire Gauge | 14-10 AWG (Cu), 12-10 AWG (Al) |
| Max Wire | 10 AWG |
| Min Wire | 14 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, Undervoltage Release |
|---|---|
| Accessories | Lugs |
| Standards | NEMA AB 1, UL 489 |
| Approval | CSA, UL |
| Temp Rating | 40C |
| Construction Features | HACR Rated, Non-Interchangeable Trip |
Product FAQs
10 answersWhich panelboards are compatible with the EF3B025 circuit breaker?
This breaker is designed to bolt into Siemens P1, P2, and P3 panelboards, as well as legacy I-T-E panelboards.
Is there a modern replacement for the legacy EF3B025?
Yes. While the EF3B025 is a legacy EF-frame device, the Siemens ED63B025 serves as its modern substitute for panel upgrades.
Can this breaker replace older I-T-E EF-frame breakers?
Yes, this Siemens breaker is a direct replacement for vintage I-T-E EF-frame breakers with matching specifications, ensuring compatibility with older installations.
What does the LI trip function code indicate on this breaker?
The LI designation stands for Long-Time and Instantaneous trip functions. It provides thermal protection against sustained overloads (Long-Time) and magnetic protection against sudden short circuits (Instantaneous).
Are the trip settings adjustable on the EF3B025?
No, this breaker features fixed thermal and fixed magnetic trip elements. The trip thresholds are factory-set and cannot be adjusted in the field.
Is the EF3B025 suitable for DC power systems?
Yes, in addition to its AC ratings, this breaker is rated for 250VDC applications with an interrupting capacity of 10kAIC.
Is the EF3B025 rated for HVAC equipment?
Yes, this breaker is HACR rated, meaning it is certified for use with heating, air conditioning, and refrigeration equipment loads.
What wire sizes and materials are supported by the breaker lugs?
The terminals accept 14 to 10 AWG copper (Cu) wire, or 12 to 10 AWG aluminum (Al) wire.
How does the EF3B025 mount into the panelboard?
It utilizes a bolt-on connection type, meaning it must be mechanically bolted directly to the panelboard busbar for a secure electrical connection.
What safety precautions are required when installing a bolt-on breaker?
Always de-energize the main power to the panelboard before installation. Verify the power is completely off using a standard voltage tester, and ensure all work is performed by a qualified electrician following local codes.
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Reviews
Review summary
Customers rate this product 5.0 out of 5 based on 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.