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Siemens NGB3B100B Molded Case Circuit Breaker

  • 100A
  • 3 Pole
  • Bolt-On
Siemens NGB3B100B
Molded Case Circuit Breaker
Brand Siemens
SKU NGB3B100B
Select Item Condition
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  • 100A
  • 3 Pole
  • Bolt-On

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Siemens NGB3B100B - 100A 3 Pole Molded Case Circuit Breaker

Siemens NGB3B100B - 100A 3 Pole Molded Case Circuit Breaker

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$370.00 In Stock

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Description

Providing 100A of thermal-magnetic protection, the Siemens NGB3B100B is a 3-pole MCCB for commercial facilities. Unlike the standard NGB3B100, this model includes factory-installed load side lugs for immediate wiring. This unit bolts into Siemens P1, P2, and P3 panelboards. As an NGB frame breaker, it serves as an exact replacement for older systems, though Siemens recommends the 3VA51 series for new builds. It delivers 100kAIC at 240VAC and 25kAIC at 480Y/277VAC, and is HACR rated.

Specifications

Key specifications
Brand Siemens
Series NGB
Amperage 100A
Poles 3
Mounting Style Bolt-On
Voltage 240VAC, 480Y/277VAC, 600Y/347VAC, 125/250VDC
Phase 3
AIC Rating 100kA @ 240VAC, 25kA @ 480Y/277VAC, 14kA @ 600Y/347VAC, 14kA @ 125/250VDC
Fit and installation
Terminal Type Lugs
For Use With Siemens P1, P2, P3 Panelboards
Wire Gauge 8-1/0 AWG (Cu), 8-2/0 AWG (Al)
Max Wire 1/0 AWG (Cu), 2/0 AWG (Al)
Min Wire 8 AWG
Protection and operation
Trip Technology Thermal Magnetic
Trip Function Code LI
Trip Function Long-Time, Instantaneous
Trip Adjustability Fixed Thermal, Fixed Magnetic
Standards and features
Available Options Shunt Trip, Auxiliary Switch, Alarm Switch, Padlock Attachment
Accessories Load Side Lugs
Standards CSA C22.2 No. 5, UL 489, NEMA AB 1
Approval CSA, HACR, UL
Temp Rating 40C
Construction Features HACR Rated, Reverse Feed

Product FAQs

6 answers
What panelboards are compatible with the Siemens NGB3B100B?

The NGB3B100B is a bolt-on molded case circuit breaker designed specifically for installation in Siemens P1, P2, and P3 series lighting and distribution panelboards.

How does the NGB3B100B connect to the electrical system?

This NGB frame breaker utilizes a bolt-on line side connection that fastens directly to the panelboard busbar. The load side features factory-installed lugs for securing branch circuit wiring.

Does the NGB3B100B include wire lugs?

Yes, it comes with factory-installed load side lugs that accept 8-1/0 AWG copper (Cu) or 8-2/0 AWG aluminum (Al) conductors.

Can the NGB3B100B replace older GB series breakers?

Yes, as an NGB frame molded case circuit breaker, it serves as an exact replacement for legacy Siemens and ITE GB family breakers in existing panelboards.

What is the difference between Siemens NGB and NGG circuit breakers?

Both series utilize the same thermal-magnetic trip mechanisms, but they feature different mounting styles. The NGB frame is configured with a bolt-on line side specifically for panelboard mounting, while the NGG frame is designed for standalone base or DIN rail mounting.

Are the trip settings adjustable on the NGB3B100B?

No, this breaker features a fixed thermal and fixed magnetic trip unit. It delivers factory-set long-time and instantaneous (LI) protection for 100-amp loads and cannot be adjusted in the field.

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Reviews

4.5
Rated 4.5 out of 5 stars
Based on 8 reviews
Rating
Ratings
8 reviews
  • JH
    John H.
    Verified Buyer
    Reviewing
    Siemens NGB3B015B - 15A 3 Pole Molded Case Circuit Breaker
    I recommend this product
    Rated 5 out of 5 stars
    9/16/26
    480v breakers

    The breakers work great

  • BP
    Bland P.
    Verified Buyer
    Reviewing
    Siemens NGB3B100 - 100A 3 Pole Molded Case Circuit Breaker
    I do not recommend this product
    Rated 1 out of 5 stars
    7/22/26
    NO LUGS!!

    I ordered this breaker and it arrived with no lugs. It was advertised as new so we didn't open the box and check until the shutdown we needed it for. When we discovered the lugs were missing we sent an email requesting a set overnighted. We didn't get a response for a couple of days, at which point we had already ordered lugs from their competitor Simply Breakers. They asked for pictures and questioned weather we had ordered the correct breaker asking if we needed lugs on both sides. This is a panel breaker and their is only one configuration that I am aware of which is bolted to bus in panel and wires to the three lugs on the other side. I have never had to order lugs separately for this style of breaker. They asked for pictures of box and what was in it, of course at this point the breaker is already installed and the box is thrown away. I sent a receipt for the overnight lugs from Simply breakers and asked for whatever credit they could provide. I received crickets to date. I have never had a problem with an order in the past from super breakers, but they are to busy to even respond to my request so I will think twice before I order anything from them again. It will be my last option once all others have been exhausted. Use Simply Breakers they have better stock and service.

  • PF
    Paul F.
    Verified Buyer
    Reviewing
    Siemens NGB3B060B - 60A 3 Pole Molded Case Circuit Breaker
    I recommend this product
    Rated 5 out of 5 stars
    6/24/26
    Great service, quick shippin

    Need I say more.I have used SB. When we need it and need it quickly Always have what I need.

  • BP
    BJ P.
    Verified Buyer
    Reviewing
    Siemens NGB3B020B - 20A 3 Pole Molded Case Circuit Breaker
    I recommend this product
    Rated 5 out of 5 stars
    5/11/26
    NGB3B020B

    I recently purchased the NGB3B020B and I’m very satisfied with the quality and performance. The breaker feels solid and well-made, and installation was straightforward. It works exactly as expected and provides reliable protection for my electrical setup. Shipping was fast and the product arrived in excellent condition. I would definitely purchase from this seller again.

  • RS
    Radovan S.
    Verified Buyer
    Reviewing
    Siemens NGB3B050B - 50A 3 Pole Molded Case Circuit Breaker
    I recommend this product
    Rated 5 out of 5 stars
    3/9/26
    Absolutely amazing service.

    On Time