Siemens REF3B040 EF3B040 - 40A 3 Pole Molded Case Circuit Breaker
- 40A
- 3 Pole
- Bolt-On
Siemens
REF3B040
EF3B040 - 40A 3 Pole Molded Case Circuit Breaker
Brand
Siemens
SKU
REF3B040
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Siemens EF3B040 - 40A 3 Pole Molded Case Circuit Breaker
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Description
Part of the legacy E-Frame series, the Siemens REF3B040 is a 40A, 3-pole molded case circuit breaker designed for robust commercial use. It utilizes fixed thermal and magnetic trip units to deliver precise long-time and instantaneous (LI) protection. Designed to fit Siemens and I-T-E panelboards, this bolt-on breaker acts as an exact substitute for the obsolete EF3B040. With a maximum rating of 600VAC and 14 kAIC at 480V, this unit includes load side lugs and accommodates 14-1/0 AWG wire.Specifications
| Brand | Siemens |
|---|---|
| Part Number | REF3B040-R |
| Series | EF Frame |
| 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/ITE Panelboards, Motor Control Centers |
| Wire Gauge | 14-1/0 AWG (Cu), 12-1/0 AWG (Al) |
| Max Wire | 1/0 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, Undervoltage Release, Alarm Switch |
|---|---|
| Accessories | Load Side Lugs |
| Standards | CSA C22.2 No. 5, NEMA AB-1, UL 489 |
| Approval | CSA, UL |
| Temp Rating | 40C |
| Construction Features | Non-Interchangeable Trip |
Product FAQs
6 answersWhich panelboards are compatible with the Siemens EF3B040 circuit breaker?
This legacy E-frame breaker is designed to bolt into older Siemens P1, P2, and P3 panelboards, as well as legacy ITE enclosures and motor control centers.
What is the modern replacement for the EF3B040 circuit breaker?
The Siemens ED63B040 is the current ED-frame equivalent. It serves as the direct replacement for this legacy 40A E-frame breaker in commercial distribution systems.
What type of wire connections does the EF3B040 require?
The breaker comes equipped with standard mechanical lugs that accept 14 to 1/0 AWG copper or 12 to 1/0 AWG aluminum conductors. Always verify that the wire gauge matches the circuit requirements and is torqued to the manufacturer specifications.
Can the trip curve be adjusted on the EF3B040?
No, this breaker features a fixed thermal-magnetic trip unit. The long-time and instantaneous (LI) protection settings are factory-calibrated and cannot be modified in the field.
Is the EF3B040 suitable for HVAC equipment?
Yes, this breaker is HACR rated, meaning it is approved for use with heating, air conditioning, and refrigeration equipment that requires this specific circuit protection standard.
How does the EF3B040 mount into the panelboard?
It utilizes a bolt-on mounting style, meaning the breaker must be physically bolted to the panelboard bus connections rather than snapping or plugging into place. Ensure the panel is de-energized before installation.
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