Skip to main content
Expedited shipping available at checkout

Siemens NGB3B045B Molded Case Circuit Breaker

  • 45A
  • 3 Pole
  • Bolt-On
Siemens NGB3B045B
Molded Case Circuit Breaker
Brand Siemens
SKU NGB3B045B
Select Item Condition
Earn 591 SuperPoints
  • 45A
  • 3 Pole
  • Bolt-On

Quantity

Bulk Pricing
Send your parts list for a volume quote.
Siemens NGB3B045B - 45A 3 Pole Molded Case Circuit Breaker

Siemens NGB3B045B - 45A 3 Pole Molded Case Circuit Breaker

New

$591.60 In Stock

Quantity

Similar Items

Description

Operating at up to 600Y/347VAC, the Siemens NGB3B045B is a 3-pole, 45A molded case circuit breaker. It provides essential LI protection for commercial electrical systems. This SENTRON series breaker bolts into Siemens P1, P2, P3, P4, and P5 panelboards. It features a trip-free mechanism, is HACR rated, and accepts standard lug connections. Offering 100kAIC at 240VAC, it delivers high-performance fault clearing. It is replaced by 3VA5145-4ED36-0AA0 (requires kit for P1-P3 panels).

Specifications

Key specifications
Brand Siemens
Part Number NGB3B045B
Series NGB
Amperage 45A
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, P4, P5 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 (3TC1GG20)
Standards CSA C22.2 No. 5, UL 489, NEMA AB 1
Approval CSA, HACR, UL
Temp Rating 40C
Construction Features HACR Rated, Reverse Feed, Trip-Free Mechanism

Product FAQs

8 answers
Which Siemens panelboards accept the NGB3B045B breaker?

This bolt-on breaker is designed for use in Siemens P1, P2, P3, P4, and P5 series panelboards. It mounts directly to the panel bus using bolted connections.

What wire sizes and materials are supported by the lugs on this breaker?

The factory-installed lugs accept 8 AWG to 1/0 AWG copper wire, or 8 AWG to 2/0 AWG aluminum wire. Ensure proper torque specifications are followed during installation as noted on the breaker faceplate.

Can the NGB3B045B be used in DC applications?

Yes, this breaker is rated for DC systems up to 125/250V DC with a maximum interrupting capacity of 14kAIC.

Are the thermal and magnetic trip settings adjustable on the NGB3B045B?

No, this breaker features fixed thermal and fixed magnetic trip elements for both long-time and instantaneous protection.

What frame size does the NGB3B045B belong to?

It is part of the Siemens Sentron series GB and GG frame group. This is a compact molded case frame commonly used for branch circuit protection in commercial panelboards.

Does this breaker provide ground fault or arc fault protection?

No, the NGB3B045B provides standard thermal-magnetic protection for overloads and short circuits only. It does not include GFCI or AFCI circuitry.

How does the NGB3B045B connect to the panelboard bus?

It utilizes a bolt-on connection type. You will need the appropriate mounting hardware to secure the breaker directly to the busbars in compatible Siemens panelboards.

What is the maximum interrupting rating for this breaker on a 480V system?

When installed in a 480Y/277V AC system, the breaker carries a 25kAIC interrupting rating. For 240V AC systems, the rating increases to 100kAIC.

SuperClub

Join free. Get 500 SuperPoints.

Earn points on eligible purchases and redeem them at checkout.

100 SuperPoints = $1 off.

Warranties

60-Day Warranty

Your purchase includes 60 days of SuperBreakers warranty coverage.

Get a Quote

Don’t see what you’re looking for?

We source obsolete and hard-to-find parts every day.

Shipping

Free Shipping Policy

Parcel shipments with item value over $99 qualify for free economy shipping within the continental US. Please call to confirm special handling instructions. We do not charge a handling fee or require a minimum amount on any order. SuperBreakers does not ship on customer accounts.

Read our full shipping policy

Same Day Shipping

We strive to ship out your items the same day the order is placed. In rare circumstances SuperBreakers may reserve up to 5 business days to consolidate orders for complete shipment.

Expedited Shipments

Orders being shipped via Next Day Air, 2 Day Shipping or 3 Day Shipping must be received by 3 PM EST to guarantee same-day shipments. Expedited orders only ship on normal business days. Shipments will NOT be sent out on Saturdays and Sundays.

International Shipping

All International orders require a $1,000 minimum order threshold. Due to the special nature of these shipments, we require that these be placed with a SuperBreakers representative. Additional shipping and instructions will apply. All International Orders are Non-Cancel and Non-Refundable.

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