Siemens FJ3B100 Molded Case Circuit Breaker
- 100A
- 3 Pole
- Bolt-On
Quantity
Siemens FJ3B100 - 100A 3 Pole Molded Case Circuit Breaker
Re-Certified
Quantity
Description
Engineered for robust power distribution, this 100A, 3-pole molded case circuit breaker utilizes fixed thermal and magnetic trip elements to protect against overloads and short circuits. It mounts securely into legacy Siemens and I-T-E enclosures, specifically fitting FC, CDP, and SB panelboards. While this FJ-type frame is an older design, it remains a vital replacement component and is superseded by the FD63B100. The breaker operates safely up to 600VAC, offering a 22 kAIC rating at 240VAC.Specifications
| Brand | Siemens |
|---|---|
| Part Number | FJ3B100 |
| Series | FJ |
| Amperage | 100A |
| Poles | 3 |
| Mounting Style | Bolt-On |
| Voltage | 600VAC, 250VDC |
| Phase | 3 |
| AIC Rating | 22kA @ 240VAC, 14kA @ 480VAC, 14kA @ 600VAC, 10kA @ 250VDC |
| Frame Type | FJ |
|---|---|
| Terminal Type | Lugs |
| For Use With | Siemens / I-T-E Panelboards (e.g., FC, CDP, SB) |
| Wire Gauge | 6 AWG - 350 kcmil (Cu/Al) |
| Max Wire | 350 kcmil |
| Min Wire | 6 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, Padlock Attachment |
|---|---|
| Accessories | Lugs |
| Standards | UL 489, CSA C22.2 No. 5, NEMA AB-1 |
| Approval | CSA, UL |
| Temp Rating | 40C |
| Construction Features | Non-Interchangeable Trip, Reverse Feed |
Product FAQs
5 answersWhich panelboards are compatible with the FJ3B100 circuit breaker?
This breaker is designed to mount into legacy Siemens and I-T-E enclosures. It specifically fits FC, CDP, and SB series panelboards and switchboards.
Is the FJ3B100 an obsolete model, and what is the direct replacement?
Yes, the FJ frame is a legacy design originally manufactured by I-T-E and Siemens. It has been superseded by the FD63B100. Note that physical dimensions and mounting hardware may differ slightly depending on your specific enclosure.
Can the trip unit on the FJ3B100 be adjusted in the field?
No, this breaker features a fixed thermal and fixed magnetic trip unit. The long-time and instantaneous trip settings are factory calibrated and cannot be modified by the user.
What type of conductors can be used with the factory lugs on this breaker?
The standard lugs on the FJ3B100 are rated for both copper and aluminum (Cu/Al) conductors, accepting wire sizes from 6 AWG up to 350 kcmil.
Does the FJ3B100 support field-installable accessories?
While accessories like shunt trips and auxiliary switches were manufactured for the FJ frame, they can be difficult to install in the field. It is recommended that only experienced technicians attempt to retrofit internal accessories into these legacy breakers.
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Reviews
Review summary
Customers rate this product 5.0 out of 5 based on 3 reviews.
- JMJoseph M.Verified BuyerReviewingSiemens / ITE FJ3S225 - 225A 3 Pole Molded Case SwitchI recommend this productRated 5 out of 5 stars3/20/26Siemens / ITE FJ3S225 - 225A 3 Pole Molded Case Switch
Correct item.
- BGBrad G.ReviewingSiemens / ITE FJ3B200 - 200A 3 Pole Molded Case Circuit BreakerI recommend this productRated 5 out of 5 stars5/19/21Great Service
We have had great luck with this company!! Great shipping and excellent customer service!
- CGClyde G.ReviewingSiemens FJ3B225 - 225A 3 Pole Molded Case Circuit BreakerI recommend this productRated 5 out of 5 stars3/8/18Had good results with your
Had good results with your people they was very helpful. Shipping was good and on time and products was right.