Siemens REF3B090 EF3B090 - 90A 3 Pole Molded Case Circuit Breaker
- 90A
- 3 Pole
- Bolt-On
Siemens
REF3B090
EF3B090 - 90A 3 Pole Molded Case Circuit Breaker
Brand
Siemens
SKU
REF3B090
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Siemens EF3B090 - 90A 3 Pole Molded Case Circuit Breaker
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Description
Engineered for industrial power distribution, the Siemens REF3B090 operates as a 90-amp, 3-pole legacy circuit breaker. It delivers reliable thermal-magnetic protection with fixed long-time and instantaneous trip functions. This E-frame component mounts securely into older Siemens and I-T-E panelboards via a bolt-on connection. It frequently replaces aging EF3B090 breakers, though the series is now superseded by the ED63B090. The unit provides an 18 kAIC rating at 240VAC and 14 kAIC at 480V.Specifications
| Brand | Siemens |
|---|---|
| Part Number | REF3B090-R |
| Series | EF |
| Amperage | 90A |
| 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, Switchboards |
| 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, Alarm Switch, Undervoltage Release |
|---|---|
| Accessories | Load Side Lugs Included |
| Standards | NEMA AB-1, UL 489 |
| Approval | CSA, UL |
| Temp Rating | 40C |
| Construction Features | Non-Interchangeable Trip |
Product FAQs
6 answersWhich panelboards and switchboards are compatible with the Siemens EF3B090?
This legacy E-frame breaker is designed to bolt into older Siemens and I-T-E enclosures. It is specifically compatible with FC-1 panelboards and FC-20 switchboards.
Is the Siemens EF3B090 obsolete, and what is the direct replacement?
Yes, the EF3B090 is a legacy breaker that has been superseded. Facilities looking to upgrade or replace this unit can cross-reference it with the newer Siemens ED63B090, which serves as the modern equivalent.
How does the EF3B090 mount into the panelboard?
This is a bolt-on molded case circuit breaker. It secures directly to the panelboard bus using bolted connections, ensuring a stable and reliable contact in commercial and industrial environments.
What are the interrupting capacity (AIC) ratings for this 90A breaker?
The EF3B090 provides an interrupting capacity of 18kA at 240VAC, 14kA at 480VAC, 14kA at 600VAC, and 10kA at 250VDC, making it suitable for standard interrupting capacity applications across both AC and DC systems.
What wire sizes and materials are accepted by the load side lugs on the EF3B090?
The included load side lugs accept wire gauges from 10 AWG up to 1/0 AWG. The terminals are rated for use with both copper (Cu) and aluminum (Al) conductors, providing flexibility for various field wiring requirements.
What type of trip unit is equipped on the EF3B090?
It features a non-interchangeable, thermal-magnetic trip unit with fixed long-time and instantaneous (LI) trip functions. This provides reliable, standard overcurrent and short-circuit protection without the need for field adjustments.
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