Built for commercial panelboards, the Siemens NGB3B020B is a 20A, 3-phase molded case circuit breaker with thermal-magnetic trip technology. It provides reliable long-time and instantaneous protection for industrial systems. The breaker is designed to mount into Siemens P1, P2, and P3 panels using a secure bolt-on connection. Featuring HACR, HID, and SWD ratings, it supports versatile applications. For modern upgrades, it is replaced by the 3VA5120-4ED31-0AA0 using a mounting strap kit.
What panelboards accept the Siemens NGB3B020B circuit breaker?
This branch breaker is designed specifically for installation in Siemens P1, P2, and P3 series lighting and distribution panelboards.
How does the NGB3B020B differ from Siemens BQD series breakers?
Both NGB and BQD series breakers share the same physical footprint and are used in Siemens P-series panelboards. However, the NGB series provides significantly higher interrupting capacities, such as 100kA at 240VAC, making it suitable for systems with higher available fault currents.
Can this 3-pole breaker be used in direct current (DC) systems?
Yes, the NGB3B020B carries a DC rating of 14kA at 125/250VDC, making it an appropriate choice for specific industrial controls, battery plants, and other DC power configurations.
What wire sizes do the factory lugs accommodate?
The factory-installed mechanical lugs accept 14 to 6 AWG copper wire and 12 to 6 AWG aluminum wire. Always ensure proper torque specifications are applied during termination.
How does the bolt-on mounting style benefit industrial installations?
Bolt-on breakers are fastened directly to the panelboard bus with screws. This creates a secure, low-resistance electrical connection that prevents loosening from vibration, which is critical in commercial and heavy industrial environments.
What protection does the fixed thermal-magnetic trip unit provide?
The non-adjustable thermal-magnetic (LI) trip mechanism offers dual-level safety. The thermal element responds to sustained overloads to prevent overheating, while the magnetic element trips instantaneously to clear severe short circuits and protect downstream equipment.
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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.
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.
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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
Review summary
Customers rate this product 4.5 out of 5 based on 8 reviews.
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